Методические материалы Лохтурова Вячеслава

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====== Система Kubernetes ======

  * [[https://habr.com/ru/companies/vk/articles/645985/|Почему Kubernetes — это новый Linux: 4 аргумента]]

  * [[https://kubernetes.io/ru/docs/home/|Документация по Kubernetes (на русском)]]

  * [[https://youtu.be/sLQefhPfwWE|youtube Введение в Kubernetes на примере Minikube]]
  * [[https://www.youtube.com/playlist?list=PLg5SS_4L6LYvN1RqaVesof8KAf-02fJSi|youtube Kubernetes на Русском Языке
12 видео]]

  * [[https://habr.com/ru/company/domclick/blog/577964/|Ультимативный гайд по созданию CI/CD в GitLab с автодеплоем в Kubernetes на голом железе всего за 514$ в год ( ͡° ͜ʖ ͡°)]]
  * [[https://habr.com/ru/company/flant/blog/513908/|Полноценный Kubernetes с нуля на Raspberry Pi]]
  * [[https://habr.com/ru/companies/domclick/articles/566224/|Различия между Docker, containerd, CRI-O и runc]]
  * [[https://daily.dev/blog/kubernetes-cni-comparison-flannel-vs-calico-vs-canal|Kubernetes CNI Comparison: Flannel vs Calico vs Canal]]
  * [[https://habr.com/ru/companies/slurm/articles/464987/|Хранилища в Kubernetes: OpenEBS vs Rook (Ceph) vs Rancher Longhorn vs StorageOS vs Robin vs Portworx vs Linstor]]
  * [[https://parshinpn.ru/ru/blog/external-connectivity-kubernetes-calico|Настраиваем сетевую связность внешнего узла с кластером Kubernetes (route reflector)]]

  * [[https://habr.com/ru/company/vk/blog/542730/|11 факапов PRO-уровня при внедрении Kubernetes и как их избежать]]

  * [[https://github.com/dgkanatsios/CKAD-exercises|A set of exercises that helped me prepare for the Certified Kubernetes Application Developer exam]]

  * [[https://www.youtube.com/watch?v=XZQ7-7vej6w|Наш опыт с Kubernetes в небольших проектах / Дмитрий Столяров (Флант)]]

  * [[https://habr.com/ru/companies/aenix/articles/541118/|Ломаем и чиним Kubernetes]]



===== Инструмент командной строки kubectl =====

  * [[https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands]]
  * [[https://kubernetes.io/ru/docs/reference/kubectl/cheatsheet/|Шпаргалка по kubectl]]

==== Установка ====

=== Linux ===
<code>
# curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl

# chmod +x kubectl

# mv kubectl /usr/local/bin/
</code>

=== Windows ===

  * [[https://kubernetes.io/docs/tasks/tools/install-kubectl-windows/|Install and Set Up kubectl on Windows]]

<code>
cmder$ curl -LO "https://dl.k8s.io/release/v1.29.0/bin/windows/amd64/kubectl.exe"

cmder$ mv kubectl.exe /usr/bin
</code>

==== Подключение к кластеру ====

<code>
mkdir ~/.kube/

scp root@192.168.X.2N1:.kube/config ~/.kube/

cat ~/.kube/config
</code><code>
...
    server: https://192.168.X.2N1:6443
...
</code><code>
kubectl version

kubectl get all -o wide --all-namespaces
kubectl get all -o wide -A
</code>
=== Настройка автодополнения ===
<code>
kube1:~# less /etc/bash_completion.d/kubectl.sh

  или

$ cat ~/.profile
</code><code>
#...
source <(kubectl completion bash)

alias k=kubectl
complete -F __start_kubectl k
#...
</code>

=== Подключение к другому кластеру ===

<code>
gitlab-runner@server:~$ scp root@kube1:.kube/config .kube/config_kube1

gitlab-runner@server:~$ cat .kube/config_kube1
</code><code>
...
    .kube/config_kube1
...
</code><code>
gitlab-runner@server:~$ export KUBECONFIG=~/.kube/config_kube1

gitlab-runner@server:~$ kubectl get nodes
</code>

===== Установка minikube =====

  * [[https://minikube.sigs.k8s.io/docs/start/|Documentation/Get Started/minikube start]]
  * [[https://stackoverflow.com/questions/42564058/how-can-i-use-local-docker-images-with-minikube|How can I use local Docker images with Minikube?]]

<code>
root@server:~# apt install -y curl wget apt-transport-https

root@server:~# wget https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64

root@server:~# mv minikube-linux-amd64 /usr/local/bin/minikube

root@server:~# chmod +x /usr/local/bin/minikube
</code>

  * Технология Docker [[Технология Docker#Предоставление прав непривилегированным пользователям]]

<code>
gitlab-runner@server:~$ time minikube start --driver=docker --insecure-registry "server.corpX.un:5000"
real    41m8.320s
...

gitlab-runner@server:~$ minikube status

gitlab-runner@server:~$ minikube ip
</code>


==== minikube kubectl ====
<code>
gitlab-runner@server:~$ minikube kubectl -- get pods -A

gitlab-runner@server:~$ cat ~/.profile
</code><code>
#...
# not work in gitlab-ci
alias kubectl='minikube kubectl --'
#...
</code><code>
gitlab-runner@server:~$ kubectl get pods -A
</code>

или

<code>
# cp -v /home/gitlab-runner/.minikube/cache/linux/amd64/v*/kubectl /usr/local/bin/
</code>

или

  * [[#Инструмент командной строки kubectl]]

==== minikube addons list ====
<code>
gitlab-runner@server:~$ minikube addons list

gitlab-runner@server:~$ minikube addons configure registry-creds
...
Do you want to enable Docker Registry? [y/n]: y
-- Enter docker registry server url: http://server.corpX.un:5000
-- Enter docker registry username: student
-- Enter docker registry password:
...

gitlab-runner@server:~$ minikube addons enable registry-creds
</code>

==== minikube start stop delete ====
<code>
gitlab-runner@server:~$ ###minikube stop

gitlab-runner@server:~$ ### minikube delete
gitlab-runner@server:~$ ### rm -rv .minikube/

gitlab-runner@server:~$ ###minikube start
</code>
===== Кластер Kubernetes =====


==== Развертывание через kubeadm ====

  * [[https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/install-kubeadm/|Installing kubeadm]]
  * [[https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/|kubernetes.io Creating a cluster with kubeadm]]

  * [[https://www.linuxtechi.com/install-kubernetes-on-ubuntu-22-04/|How to Install Kubernetes Cluster on Ubuntu 22.04]]
  * [[https://www.linuxtechi.com/install-kubernetes-cluster-on-debian/|https://www.linuxtechi.com/install-kubernetes-cluster-on-debian/|How to Install Kubernetes Cluster on Debian 12 | 11]]

  * [[https://www.baeldung.com/ops/kubernetes-cluster-components|Kubernetes Cluster Components]]


=== Подготовка узлов ===

<code>
node1# ssh-keygen

node1# ssh-copy-id node2
node1# ssh-copy-id node3

node1# bash -c '
swapoff -a
ssh node2 swapoff -a
ssh node3 swapoff -a
'

node1# bash -c '
sed -i"" -e "/swap/s/^/#/" /etc/fstab
ssh node2 sed -i"" -e "/swap/s/^/#/" /etc/fstab
ssh node3 sed -i"" -e "/swap/s/^/#/" /etc/fstab
'
</code>

=== Установка ПО ===

=== !!! Обратитесь к преподавателю !!! ===

== Установка и настройка CRI ==
<code>
node1_2_3# apt-get install -y docker.io

Проверяем, если: 
node1# containerd config dump | grep SystemdCgroup
не равно:
           SystemdCgroup = true
то, выполняем следующие 4-ре команды:

bash -c 'mkdir -p /etc/containerd/
ssh node2 mkdir -p /etc/containerd/
ssh node3 mkdir -p /etc/containerd/
'
bash -c 'containerd config default > /etc/containerd/config.toml
ssh node2 "containerd config default > /etc/containerd/config.toml"
ssh node3 "containerd config default > /etc/containerd/config.toml"
'
bash -c 'sed -i "s/SystemdCgroup \= false/SystemdCgroup \= true/g" /etc/containerd/config.toml
ssh node2 sed -i \"s/SystemdCgroup \= false/SystemdCgroup \= true/g\" /etc/containerd/config.toml
ssh node3 sed -i \"s/SystemdCgroup \= false/SystemdCgroup \= true/g\" /etc/containerd/config.toml
'
bash -c 'service containerd restart
ssh node2 service containerd restart
ssh node3 service containerd restart
'
</code>
== Подключаем репозиторий и устанавливаем ПО ==
<code>
bash -c 'mkdir -p /etc/apt/keyrings
ssh node2 mkdir -p /etc/apt/keyrings
ssh node3 mkdir -p /etc/apt/keyrings
'

bash -c 'curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg
ssh node2 "curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg"
ssh node3 "curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.30/deb/Release.key | gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg"
'

bash -c 'echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /" | tee /etc/apt/sources.list.d/kubernetes.list
ssh node2 echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /" \| tee /etc/apt/sources.list.d/kubernetes.list
ssh node3 echo "deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.30/deb/ /" \| tee /etc/apt/sources.list.d/kubernetes.list
'

bash -c 'apt-get update && apt-get install -y kubelet kubeadm kubectl
ssh node2 "apt-get update && apt-get install -y kubelet kubeadm kubectl"
ssh node3 "apt-get update && apt-get install -y kubelet kubeadm kubectl"
'
Время выполнения: 2 минуты
</code>

=== Инициализация master ===

  * [[https://stackoverflow.com/questions/70416935/create-same-master-and-working-node-in-kubenetes|Create same master and working node in kubenetes]]

<code>
root@node1:~# kubeadm init --pod-network-cidr=10.244.0.0/16 --apiserver-advertise-address=192.168.X.201
Время выполнения: 3 минуты

root@node1:~# mkdir -p $HOME/.kube

root@node1:~# cp -i /etc/kubernetes/admin.conf $HOME/.kube/config
</code>
=== Настройка сети ===
<code>
root@nodeN:~# lsmod | grep br_netfilter
</code>
  * [[Управление ядром и модулями в Linux#Модули ядра]]
<code>
root@node1:~# kubectl apply -f https://raw.githubusercontent.com/coreos/flannel/master/Documentation/kube-flannel.yml
</code>
=== Проверка работоспособности ===
<code>
root@node1:~# kubectl get pod --all-namespaces -o wide

root@node1:~# kubectl get --raw='/readyz?verbose'
</code>

=== Подключение worker ===

<code>
root@node2_3:~# curl -k https://node1:6443/livez?verbose

root@node2_3:~# kubeadm join 192.168.X.201:6443 --token NNNNNNNNNNNNNNNNNNNN \
        --discovery-token-ca-cert-hash sha256:NNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNNN

root@node2_3:~# curl -sSL http://127.0.0.1:10248/healthz

root@node1:~# kubeadm token list

root@node1:~# kubeadm token create --print-join-command
</code>
=== Проверка состояния ===
<code>
root@node1:~# kubectl cluster-info

root@node1:~# kubectl get nodes -o wide

root@node1:~# kubectl describe node node2
</code>

=== Удаление узла ===

  * [[https://stackoverflow.com/questions/56064537/how-to-remove-broken-nodes-in-kubernetes|How to remove broken nodes in Kubernetes]]

<code>
$ kubectl cordon kube3

$ time kubectl drain kube3 #--ignore-daemonsets --delete-emptydir-data --force

$ kubectl delete node kube3
</code>

=== Удаление кластера ===

  * [[https://stackoverflow.com/questions/44698283/how-to-completely-uninstall-kubernetes|How to completely uninstall kubernetes]]

<code>
node1# bash -c '
kubeadm reset
ssh node2 kubeadm reset
ssh node3 kubeadm reset
'
</code>

=== Настройка доступа к Insecure Private Registry ===
=== !!! Обратитесь к преподавателю !!! ===

  * [[https://github.com/containerd/containerd/issues/4938|Unable to pull image from insecure registry, http: server gave HTTP response to HTTPS client #4938]]
  * [[https://github.com/containerd/containerd/issues/3847|Containerd cannot pull image from insecure registry #3847]]

  * [[https://mrzik.medium.com/how-to-configure-private-registry-for-kubernetes-cluster-running-with-containerd-cf74697fa382|How to Configure Private Registry for Kubernetes cluster running with containerd]]
  * [[https://github.com/containerd/containerd/blob/main/docs/PLUGINS.md#version-header|containerd/docs/PLUGINS.md migrate config v1 to v2]]

== сontainerd ==

<code>
root@node1:~# mkdir -p /etc/containerd/

root@node1:~# ###containerd config default > /etc/containerd/config.toml

root@node1:~# cat /etc/containerd/config.toml
</code><code>
...
      [plugins."io.containerd.grpc.v1.cri".registry.mirrors]
        [plugins."io.containerd.grpc.v1.cri".registry.mirrors."server.corpX.un:5000"]
          endpoint = ["http://server.corpX.un:5000"]
...
</code><code>
node1# bash -c '
ssh node2 mkdir -p /etc/containerd/
ssh node3 mkdir -p /etc/containerd/
scp /etc/containerd/config.toml node2:/etc/containerd/config.toml
scp /etc/containerd/config.toml node3:/etc/containerd/config.toml
systemctl restart containerd
ssh node2 systemctl restart containerd
ssh node3 systemctl restart containerd
'

root@nodeN:~# containerd config dump | less
</code>

== сontainerd v3 ==

  * [[https://stackoverflow.com/questions/79305194/unable-to-pull-image-from-insecure-registry-http-server-gave-http-response-to/79308521#79308521]]

<code>
# mkdir -p /etc/containerd/certs.d/server.corpX.un:5000/

# cat /etc/containerd/certs.d/server.corpX.un:5000/hosts.toml
</code><code>
[host."http://server.corpX.un:5000"]
  capabilities = ["pull", "resolve", "push"]
  skip_verify = true
</code><code> 
# systemctl restart containerd.service
</code>

Проверка

<code>
root@nodeN:~# crictl -r unix:///run/containerd/containerd.sock pull server.corpX.un:5000/student/gowebd

root@kubeN:~# crictl pull server.corpX.un:5000/student/pywebd2
</code>
==== Развертывание через Kubespray ====

  * [[https://github.com/kubernetes-sigs/kubespray]]
  * [[https://habr.com/ru/companies/domclick/articles/682364/|Самое подробное руководство по установке высокодоступного (почти ಠ ͜ʖ ಠ ) Kubernetes-кластера]]
  * [[https://habr.com/ru/companies/X5Tech/articles/645651/|Bare-metal kubernetes-кластер на своём локальном компьютере]]
  * [[https://internet-lab.ru/k8s_kubespray|Kubernetes — установка через Kubespray]]
  * [[https://www.mshowto.org/en/ubuntu-sunucusuna-kubespray-ile-kubernetes-kurulumu.html|Installing Kubernetes on Ubuntu Server with Kubespray]]
  * [[https://kubernetes.io/docs/setup/production-environment/tools/kubespray/|Installing Kubernetes with Kubespray]]

=== Подготовка к развертыванию через Kubespray ===

  * [[Язык программирования Python#Виртуальная среда Python]]

<code>
(venv1) server# ssh-keygen

(venv1) server# ssh-copy-id kube1;ssh-copy-id kube2;ssh-copy-id kube3;ssh-copy-id kube4;

(venv1) server# git clone https://github.com/kubernetes-sigs/kubespray

(venv1) server# cd kubespray/

(venv1) server:~/kubespray# git tag -l

(venv1) server:~/kubespray# git checkout tags/v2.26.0
  или
(venv1) server:~/kubespray# git checkout tags/v2.27.0

(venv1) server:~/kubespray# time pip3 install -r requirements.txt

(venv1) server:~/kubespray# cp -rvfpT inventory/sample inventory/mycluster

(venv1) server:~/kubespray# cat inventory/mycluster/hosts.yaml
</code><code>
all:
  hosts:
    kube1:
    kube2:
    kube3:
    kube4:
  children:
    kube_control_plane:
      hosts:
        kube1:
        kube2:
    kube_node:
      hosts:
        kube1:
        kube2:
        kube3:
    etcd:
      hosts:
        kube1:
        kube2:
        kube3:
    k8s_cluster:
      children:
        kube_control_plane:
        kube_node:
    calico_rr:
      hosts: {}
</code><code>
(venv1) server:~/kubespray# ansible all -m ping -i inventory/mycluster/hosts.yaml
</code>

  * [[Сервис Ansible#Использование модулей]] Ansible для отключения swap
  * [[Сервис Ansible#Использование ролей]] Ansible для настройки сети

=== Развертывание кластера через Kubespray ===
<code>
~/kubespray# time ansible-playbook -i inventory/mycluster/hosts.yaml cluster.yml
real    45m31.796s

kube1# less ~/.kube/config

~/kubespray# ###time ansible-playbook -i inventory/mycluster/hosts.yaml reset.yml
real    7m31.796s
</code>

=== Добавление узла через Kubespray ===

  * [[https://github.com/kubernetes-sigs/kubespray/blob/master/docs/operations/nodes.md|Adding/replacing a node (github.com/kubernetes-sigs/kubespray)]]
  * [[https://nixhub.ru/posts/k8s-nodes-scale/|K8s - добавление нод через kubespray]]
  * [[https://blog.unetresgrossebite.com/?p=934|Redeploy Kubernetes Nodes with KubeSpray]]

<code>
~/kubespray# cat inventory/mycluster/hosts.yaml
</code><code>
all:
  hosts:
...
    kube4:
...
    kube_node:
      hosts:
...
        kube4:
...
</code><code>
(venv1) server:~/kubespray# time ansible-playbook -i inventory/mycluster/hosts.yaml cluster.yml
real    6m31.562s

~/kubespray# ###time ansible-playbook -i inventory/mycluster/hosts.yaml --limit=kube4 scale.yml
real    17m37.459s

$ kubectl get nodes -o wide
</code>

=== Добавление insecure_registries через Kubespray ===
<code>
~/kubespray# cat inventory/mycluster/group_vars/all/containerd.yml
</code><code>
...
containerd_insecure_registries:
  "server.corpX.un:5000": "http://server.corpX.un:5000"
containerd_registry_auth:
  - registry: server.corpX.un:5000
    username: student
    password: Pa$$w0rd
...
</code><code>
~/kubespray# time ansible-playbook -i inventory/mycluster/hosts.yaml cluster.yml
user    46m37.151s

# less /etc/containerd/config.toml
</code>

=== Управление дополнениями через Kubespray ===
<code>
~/kubespray# cat inventory/mycluster/group_vars/k8s_cluster/addons.yml
</code><code>
...
helm_enabled: true
...
ingress_nginx_enabled: true
ingress_nginx_host_network: true
...
</code>
===== Базовые объекты k8s =====

==== Deployment, Replica Sets, Pods ====

  * [[https://kubernetes.io/docs/tasks/inject-data-application/define-command-argument-container/|Define a Command and Arguments for a Container]]
  * [[https://kubernetes.io/ru/docs/reference/kubectl/docker-cli-to-kubectl/|kubectl для пользователей Docker]]
  * [[https://kubernetes.io/docs/tasks/run-application/run-stateless-application-deployment/|Run a Stateless Application Using a Deployment]]


<code>
$ kubectl api-resources

$ ###kubectl run -ti --rm my-debian --image=debian --overrides='{"spec": { "nodeSelector": {"kubernetes.io/hostname": "kube4"}}}'

$ kubectl run my-debian --image=debian -- "sleep" "60"

$ kubectl get pods

kubeN# crictl ps | grep debi
kubeN# crictl images
nodeN# ctr ns ls
nodeN# ctr -n=k8s.io image ls | grep debi

$ kubectl delete pod my-debian
$ ###kubectl delete pod my-debian --grace-period=0 --force

$ kubectl create deployment my-debian --image=debian -- "sleep" "infinity"

$ kubectl get all
$ kubectl get deployments
$ kubectl get replicasets
</code>
  * [[#Настройка автодополнения]]
<code>
$ kubectl attach my-debian-NNNNNNNNN-NNNNN

$ kubectl exec -ti my-debian-NNNNNNNNN-NNNNN -- bash
Ctrl-D
</code>
  * [[Технология Docker#Анализ параметров запущенного контейнера изнутри]]
<code>
$ kubectl get deployment my-debian -o yaml
</code>
  * [[Переменные окружения]] EDITOR
<code>
$ kubectl edit deployment my-debian

$ kubectl get pods -o wide

$ kubectl delete deployment my-debian
</code>

==== Manifest ====

  * [[https://kubernetes.io/docs/reference/glossary/?all=true#term-manifest|Kubernetes Documentation Reference Glossary/Manifest]]
<code>
$ cat my-debian-deployment.yaml
</code><code>
apiVersion: apps/v1
kind: ReplicaSet
#kind: Deployment
metadata:
  name: my-debian
spec:
  selector:
    matchLabels:
      app: my-debian
  replicas: 2
  template:
    metadata:
      labels:
        app: my-debian
    spec:
      containers:
      - name: my-debian
        image: debian
        command: ["/bin/sh"]
        args: ["-c", "while :;do echo -n random-value:;od -A n -t d -N 1 /dev/urandom;sleep 5; done"]
        resources:
          requests:
            memory: "64Mi"
            cpu: "250m"
          limits:
            memory: "128Mi"
            cpu: "500m"
      restartPolicy: Always
</code><code>
$ kubectl apply -f my-debian-deployment.yaml #--dry-run=client #-o yaml

$ kubectl logs -l app=my-debian -f
...
$ kubectl delete -f my-debian-deployment.yaml
</code>

==== namespace для своего приложения ====

==== Deployment ====

  * [[https://stackoverflow.com/questions/52857825/what-is-an-endpoint-in-kubernetes|What is an 'endpoint' in Kubernetes?]]
  * [[https://matthewpalmer.net/kubernetes-app-developer/articles/kubernetes-volumes-example-nfs-persistent-volume.html|How to use an NFS volume]]
  * [[https://www.kryukov.biz/kubernetes/lokalnye-volumes/emptydir/|emptyDir]]
  * [[https://hub.docker.com/_/httpd|The Apache HTTP Server Project - httpd Docker Official Image]]
  * [[https://habr.com/ru/companies/oleg-bunin/articles/761662/|Дополнительные контейнеры в Kubernetes и где они обитают: от паттернов к автоматизации управления]]
  * [[https://stackoverflow.com/questions/39436845/multiple-command-in-poststart-hook-of-a-container|multiple command in postStart hook of a container]]
  * [[https://stackoverflow.com/questions/33887194/how-to-set-multiple-commands-in-one-yaml-file-with-kubernetes|How to set multiple commands in one yaml file with Kubernetes?]]

<code>
$ kubectl create namespace my-ns

$ kubectl get namespaces

$ ### kubectl create deployment my-webd --image=server.corpX.un:5000/student/webd:latest --replicas=2 -n my-ns

$ ### kubectl delete deployment my-webd -n my-ns

$ mkdir ??webd-k8s/; cd $_

$ cat my-webd-deployment.yaml
</code><code>
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-webd
#  annotations:
#    kubernetes.io/change-cause: "update to ver1.2"
spec:
  selector:
    matchLabels:
      app: my-webd
  replicas: 2
  template:
    metadata:
      labels:
        app: my-webd
    spec:
      containers:
      - name: my-webd

#        image: server.corpX.un:5000/student/webd
#        image: server.corpX.un:5000/student/webd:ver1.N
#        image: httpd
#        args: ["gunicorn", "app:app", "--bind", "0.0.0.0:8000", "-k", "uvicorn.workers.UvicornWorker"]

#        imagePullPolicy: "Always"

#        lifecycle:
#          postStart:
#            exec:
#              command:
#              - /bin/sh
#              - -c
#              - |
#                #test -f /usr/local/apache2/htdocs/index.html && exit 0
#                mkdir -p /usr/local/apache2/htdocs/
#                cd /usr/local/apache2/htdocs/
#                echo "<h1>Hello from apache2 on $(hostname) at $(date)</h1>" > index.html
#                echo "<img src=img/logo.gif>" >> index.html

#        env:
#        - name: PYWEBD_DOC_ROOT
#          value: "/usr/local/apache2/htdocs/"
#        - name: PYWEBD_PORT
#          value: "4080"
#        - name: APWEBD_HOSTNAME
#          value: "apwebd.corpX.un"
#        - name: KEYCLOAK_HOSTNAME
#          value: "keycloak.corpX.un"
#        - name: REALM_NAME
#          value: "corpX"

#        livenessProbe:
#          httpGet:
#            port: 80
#            #scheme: HTTPS

#        volumeMounts:
#        - name: htdocs-volume
#          mountPath: /usr/local/apache2/htdocs


#        volumeMounts:
#        - name: nfs-volume
#          mountPath: /var/www

#      volumes:
#      - name: htdocs-volume
#        emptyDir: {}


#      volumes:
#      - name: nfs-volume
#        nfs:
#          server: server.corpX.un
#          path: /var/www

#      initContainers:
#      - name: load-htdocs-files
#        image: curlimages/curl
##        command: ['sh', '-c', 'mkdir /mnt/img; curl http://val.bmstu.ru/unix/Media/logo.gif > /mnt/img/logo.gif']
#        command: ["/bin/sh", "-c"]
#        args:
#        - |
#          test -d /mnt/img/ && exit 0
#          mkdir /mnt/img; cd /mnt/img
#          curl http://val.bmstu.ru/unix/Media/logo.gif > logo.gif
#          ls -lR /mnt/
#        volumeMounts:
#        - mountPath: /mnt
#          name: htdocs-volume

</code><code>
$ kubectl apply -f my-webd-deployment.yaml -n my-ns #--dry-run=client #-o yaml

$ kubectl get all -n my-ns -o wide

$ kubectl describe -n my-ns pod/my-webd-NNNNNNNNNN-NNNNN

$ kubectl -n my-ns logs pod/my-webd-NNNNNNNNNN-NNNNN #-c load-htdocs-files

$ kubectl logs -l app=my-webd -n my-ns 
(доступны опции -f, --tail=2000, --previous)

$ kubectl scale deployment my-webd --replicas=3 -n my-ns

$ kubectl delete pod/my-webd-NNNNNNNNNN-NNNNN -n my-ns
</code>

=== Версии deployment ===

  * [[https://learnk8s.io/kubernetes-rollbacks|How do you rollback deployments in Kubernetes?]]
  * [[https://kubernetes.io/docs/concepts/workloads/controllers/deployment/#updating-a-deployment|Updating a Deployment]]

<code>
$ ###kubectl rollout pause deployment my-webd-dep -n my-ns
$ ###kubectl set image deployment/my-webd-dep my-webd-con=server.corpX.un:5000/student/gowebd:ver1.2 -n my-ns
$ ###kubectl rollout resume deployment my-webd-dep -n my-ns

$ ###kubectl rollout status deployment/my-webd-dep -n my-ns

$ kubectl rollout history deployment/my-webd -n my-ns
</code><code>
REVISION  CHANGE-CAUSE
1         <none>
...
N         update to ver1.2
</code><code>
$ kubectl rollout history deployment/my-webd --revision=1 -n my-ns
</code><code>
...
    Image:      server.corpX.un:5000/student/webd:ver1.1
...
</code><code>
$ kubectl rollout undo deployment/my-webd --to-revision=1 -n my-ns

$ kubectl annotate deployment/my-webd kubernetes.io/change-cause="revert to ver1.1" -n my-ns

$ kubectl rollout history deployment/my-webd -n my-ns
</code><code>
REVISION  CHANGE-CAUSE
2         update to ver1.2
...
N+1        revert to ver1.1
</code>

==== Service ====

  * [[https://kubernetes.io/docs/concepts/services-networking/service/|Kubernetes Documentation Concepts Services, Load Balancing, and Networking Service]]
  * [[https://alesnosek.com/blog/2017/02/14/accessing-kubernetes-pods-from-outside-of-the-cluster/|Accessing Kubernetes Pods From Outside of the Cluster]]
  * [[https://stackoverflow.com/questions/33069736/how-do-i-get-logs-from-all-pods-of-a-kubernetes-replication-controller|How do I get logs from all pods of a Kubernetes replication controller?]]


<code>
$ ### kubectl expose deployment my-webd --type=NodePort --port=80 -n my-ns

$ ### kubectl delete svc my-webd -n my-ns

$ cat my-webd-service.yaml
</code><code>
apiVersion: v1
kind: Service
metadata:
  name: my-webd
spec:
#  type: NodePort
#  type: LoadBalancer
#  loadBalancerIP: 192.168.X.64
  selector:
    app: my-webd
  ports:
  - protocol: TCP
    port: 80
#    targetPort: 4080
#    nodePort: 30111
</code><code>
$ kubectl apply -f my-webd-service.yaml -n my-ns

$ kubectl describe svc my-webd -n my-ns

$ kubectl get endpoints -n my-ns
  или 
$ kubectl get endpointslice -n my-ns
</code>
=== NodePort ===

  * [[https://www.baeldung.com/ops/kubernetes-nodeport-range|Why Kubernetes NodePort Services Range From 30000 – 32767]]

<code>
$ kubectl get svc my-webd -n my-ns
NAME              TYPE       CLUSTER-IP       EXTERNAL-IP   PORT(S)        AGE
my-webd-svc   NodePort   10.102.135.146   <none>        80:NNNNN/TCP   18h

$ curl http://kube1,2,3:NNNNN
</code>
== NodePort Minikube ==
<code>
$ minikube service list

$ minikube service my-webd --url -n my-ns
http://192.168.49.2:NNNNN

$ curl http://192.168.49.2:NNNNN
</code>

=== LoadBalancer ===

== MetalLB ==

  * [[https://www.adaltas.com/en/2022/09/08/kubernetes-metallb-nginx/|Ingresses and Load Balancers in Kubernetes with MetalLB and nginx-ingress]]

  * [[https://metallb.universe.tf/installation/|Installation]]
  * [[https://metallb.universe.tf/configuration/_advanced_ipaddresspool_configuration/|Advanced AddressPool configuration]]
  * [[https://metallb.universe.tf/configuration/_advanced_l2_configuration/|Advanced L2 configuration]]

<code>
$ kubectl apply -f https://raw.githubusercontent.com/metallb/metallb/v0.14.3/config/manifests/metallb-native.yaml

$ kubectl -n metallb-system get all

$ cat first-pool.yaml
</code><code>
---
apiVersion: metallb.io/v1beta1
kind: IPAddressPool
metadata:
  name: first-pool
  namespace: metallb-system
spec:
  addresses:
  - 192.168.X.64/28
  autoAssign: false
#  autoAssign: true
---
apiVersion: metallb.io/v1beta1
kind: L2Advertisement
metadata:
  name: first-pool-advertisement
  namespace: metallb-system
spec:
  ipAddressPools:
  - first-pool
  interfaces:
  - eth0
</code><code>
$ kubectl apply -f first-pool.yaml

...
$ kubectl get svc my-webd -n my-ns
NAME      TYPE           CLUSTER-IP     EXTERNAL-IP     PORT(S)        AGE
my-webd   LoadBalancer   10.233.23.29   192.168.X.64   80:NNNNN/TCP   50s


$ #kubectl delete -f first-pool.yaml && rm first-pool.yaml

$ #kubectl delete -f https://raw.githubusercontent.com/metallb/metallb/v0.14.3/config/manifests/metallb-native.yaml
</code>

=== ClusterIP ===
<code>
kube1# host my-webd.my-ns.svc.cluster.local 169.254.25.10

kube1# curl my-webd.my-ns.svc.cluster.local
</code>

== port-forward ==

  * [[#Инструмент командной строки kubectl]]

<code>
node1/kube1# kubectl port-forward -n my-ns --address 0.0.0.0 services/my-webd 1234:80

cmder> kubectl port-forward -n my-ns services/my-webd 1234:80
</code>

  * http://192.168.X.2N1:1234
  * http://localhost:1234

<code>
node1/kube1# kubectl -n my-ns delete pod/my-webd...
</code>

== kubectl proxy ==

  * [[#Инструмент командной строки kubectl]]

<code>
kube1:~# kubectl proxy --address='0.0.0.0' --accept-hosts='^*$'

cmder> kubectl proxy
</code>

  * http://192.168.X.2N1:8001/api/v1/namespaces/my-ns/services/my-webd:80/proxy/
  * http://localhost:8001/api/v1/namespaces/my-ns/services/my-webd:80/proxy/


==== Удаление объектов ====
<code>
$ kubectl get all -n my-ns

$ kubectl delete -n my-ns -f my-webd-deployment.yaml,my-webd-service.yaml

или

$ kubectl delete namespace my-ns
</code>

==== Ingress ====

  * [[https://kubernetes.github.io/ingress-nginx/deploy/#quick-start|NGINX ingress controller quick-start]]
  * [[#Работа с готовыми Charts]]

=== Minikube ingress-nginx-controller ===

  * [[https://kubernetes.io/docs/tasks/access-application-cluster/ingress-minikube/|Set up Ingress on Minikube with the NGINX Ingress Controller]]
  * [[https://www.golinuxcloud.com/kubectl-port-forward/|kubectl port-forward examples in Kubernetes]]

<code>
server# cat /etc/bind/corpX.un
</code><code>
...
webd A 192.168.49.2
</code><code>
gitlab-runner@server:~$ minikube addons enable ingress
</code>

=== Baremetal ingress-nginx-controller  ===

  * [[https://github.com/kubernetes/ingress-nginx/tags]] Версии
  * [[https://stackoverflow.com/questions/61616203/nginx-ingress-controller-failed-calling-webhook|Nginx Ingress Controller - Failed Calling Webhook]]
  * [[https://stackoverflow.com/questions/51511547/empty-address-kubernetes-ingress|Empty ADDRESS kubernetes ingress]]
  * [[https://kubernetes.github.io/ingress-nginx/deploy/#bare-metal-clusters|ingress-nginx/deploy/bare-metal-clusters]]

<code>
server# cat /etc/bind/corpX.un
</code><code>
...
webd            A       192.168.X.202
                A       192.168.X.203
gowebd          CNAME   webd
</code><code>
node1# curl https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.3.1/deploy/static/provider/baremetal/deploy.yaml | tee ingress-nginx.controller-v1.3.1.baremetal.yaml

node1# cat ingress-nginx.controller-v1.3.1.baremetal.yaml
</code><code>
...
kind: Deployment
...
spec:
...
  replicas: 3    ### insert this (equial count of worker nodes)
  template:
...
      terminationGracePeriodSeconds: 300
      hostNetwork: true                    ###insert this
      volumes:
...
</code><code>
node1# kubectl apply -f ingress-nginx.controller-v1.3.1.baremetal.yaml

node1# kubectl get all -n ingress-nginx

node1# ###kubectl delete -A ValidatingWebhookConfiguration ingress-nginx-admission

node1# ###kubectl delete -f ingress-nginx.controller-v1.3.1.baremetal.yaml
</code>

=== Ingress baremetal DaemonSet ===
<code>
kube1:~# mkdir -p ingress-nginx; cd $_

kube1:~/ingress-nginx# curl https://raw.githubusercontent.com/kubernetes/ingress-nginx/controller-v1.12.0/deploy/static/provider/baremetal/deploy.yaml | tee ingress-nginx.controller-v1.12.0.baremetal.yaml

kube1:~/ingress-nginx# cat ingress-nginx.controller-v1.12.0.baremetal.yaml
</code><code>
...
apiVersion: v1
#data: null
data:
  allow-snippet-annotations: "true"
  use-forwarded-headers: "true"
kind: ConfigMap
...
#kind: Deployment
kind: DaemonSet
...
#  strategy:
#    rollingUpdate:
#      maxUnavailable: 1
#    type: RollingUpdate
...
      hostNetwork: true                    ### insert this
      terminationGracePeriodSeconds: 300
      volumes:
...
</code><code>
kube1:~/ingress-nginx# kubectl apply -f ingress-nginx.controller-v1.12.0.baremetal.yaml

kube1:~/ingress-nginx# kubectl -n ingress-nginx get pods -o wide

kube1:~/ingress-nginx# kubectl -n ingress-nginx describe service/ingress-nginx-controller
</code><code>
...
Endpoints:                192.168.X.221:80,192.168.X.222:80,192.168.X.223:80
...
</code><code>
kube1:~/ingress-nginx# ###kubectl delete -f ingress-nginx.controller-v1.12.0.baremetal.yaml
</code>

=== Управление конфигурацией ingress-nginx-controller  ===
<code>
master-1:~$ kubectl exec -n ingress-nginx pods/ingress-nginx-controller-<TAB> -- cat /etc/nginx/nginx.conf | tee nginx.conf

master-1:~$ kubectl edit -n ingress-nginx configmaps ingress-nginx-controller
</code><code>
...
data:
  use-forwarded-headers: "true"
...
</code>

=== ingress example ===

  * [[https://stackoverflow.com/questions/49829452/why-ingress-serviceport-can-be-port-and-targetport-of-service|!!! The NGINX ingress controller does not use Services to route traffic to the pods]]
  * [[https://stackoverflow.com/questions/54459015/how-to-configure-ingress-to-direct-traffic-to-an-https-backend-using-https|how to configure ingress to direct traffic to an https backend using https]]

<code>
kube1# ### kubectl create ingress my-ingress --class=nginx --rule="webd.corpX.un/*=my-webd:80" -n my-ns

kube1# cat my-ingress.yaml
</code><code>
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: my-ingress
#  annotations:
#    nginx.ingress.kubernetes.io/canary: "true"
#    nginx.ingress.kubernetes.io/canary-weight: "30"
spec:
  ingressClassName: nginx
#  tls:
#  - hosts:
#    - gowebd.corpX.un
#    secretName: gowebd-tls
  rules:
  - host: webd.corpX.un
    http:
      paths:
      - backend:
          service:
            name: my-webd
            port:
              number: 4080
        path: /
        pathType: Prefix
  - host: gowebd.corpX.un
    http:
      paths:
      - backend:
          service:
            name: my-gowebd
            port:
              number: 80
        path: /
        pathType: Prefix
</code><code>
kube1# kubectl apply -f my-ingress.yaml -n my-ns

kube1# kubectl get ingress -n my-ns
NAME      CLASS   HOSTS                             ADDRESS                         PORTS   AGE
my-webd   nginx   webd.corpX.un,gowebd.corpX.un   192.168.X.202,192.168.X.203   80      14m
</code>
  * [[Утилита curl]]
<code>
$ curl webd.corpX.un
$ curl gowebd.corpX.un
$ curl https://gowebd.corpX.un #-kv

$ curl http://nodeN/ -H "Host: webd.corpX.un"
$ curl --connect-to "":"":kubeN:443 https://gowebd.corpX.un #-vk

$ kubectl logs -n ingress-nginx -l app.kubernetes.io/name=ingress-nginx -f

kube1# ### kubectl delete ingress my-ingress -n my-ns
</code>

=== secrets tls ===

  * [[https://devopscube.com/configure-ingress-tls-kubernetes/|How To Configure Ingress TLS/SSL Certificates in Kubernetes]]

<code>
$ kubectl create secret tls gowebd-tls --key gowebd.key --cert gowebd.crt -n my-ns
    
$ kubectl get secrets -n my-ns

$ kubectl get secret/gowebd-tls -o yaml -n my-ns

$ ###kubectl delete secret/gowebd-tls -n my-ns
</code>
=== cert-manager ===

  * [[Letsencrypt Certbot]]
  * [[https://cert-manager.io/docs/tutorials/acme/nginx-ingress/|cert-manager Securing NGINX-ingress]]
  * [[Сервис Keepalived]] для 443-го порта
  * [[Решение HAProxy]] для 80-го (cert-manager проверяет ссылку изнутри кластера)
<code>
увидеть ссылку
student@debian:~/gowebd-k8s$ kubectl -n my-ns get ingress -o yaml | less

увидеть обработчик
student@debian:~/gowebd-k8s$ kubectl -n my-ns get pods
NAME                        READY   STATUS    RESTARTS   AGE
cm-acme-http-solver-5j2pr   1/1     Running   0          28s
my-webd-78ffd6cc5f-4qplt    1/1     Running   0          4d14h
my-webd-78ffd6cc5f-zpcsh    1/1     Running   0          4d14h
</code>
==== Volumes ====

=== hostPath и nodeSelector ===

  * [[Средства программирования shell#Ресурсы Web сервера на shell]] на kube3

<code>
kube1# kubectl label nodes kube3 htdocs-node=yes

kube1# kubectl get nodes --show-labels

kube1:~/pywebd-k8s# cat my-webd-deployment.yaml
</code><code>
...
        volumeMounts:
        - name: htdocs-volume
          mountPath: /usr/local/apache2/htdocs

#        lifecycle:
#        ...

      volumes:
      - name: htdocs-volume
        hostPath:
          path: /var/www/

      nodeSelector:
        htdocs-node: "yes"

#      initContainers:
#      ...
</code>

=== PersistentVolume и PersistentVolumeClaim ===

  * [[https://qna.habr.com/q/629022|Несколько Claim на один Persistent Volumes?]]
  * [[https://serveradmin.ru/hranilishha-dannyh-persistent-volumes-v-kubernetes/|Хранилища данных (Persistent Volumes) в Kubernetes]]
  * [[https://stackoverflow.com/questions/59915899/limit-persistent-volume-claim-content-folder-size-using-hostpath|Limit persistent volume claim content folder size using hostPath]]
  * [[https://stackoverflow.com/questions/63490278/kubernetes-persistent-volume-hostpath-vs-local-and-data-persistence|Kubernetes persistent volume: hostpath vs local and data persistence]]
  * [[https://www.alibabacloud.com/blog/kubernetes-volume-basics-emptydir-and-persistentvolume_594834|Kubernetes Volume Basics: emptyDir and PersistentVolume]]

<code>
kube1:~/pv# cat my-ha-pv.yaml
</code><code>
apiVersion: v1
kind: PersistentVolume
metadata:
  name: my-pv-kube3-sz-128m-num-001
#  name: my-pv-kube3-keycloak
#  labels:
#    type: local
spec:
## comment storageClassName for keycloak
  storageClassName: my-ha-sc
  capacity:
    storage: 128Mi
#    storage: 8Gi
  accessModes:
    - ReadWriteOnce
  hostPath:
#    path: /disk2
    path: /disk2/dir1
  persistentVolumeReclaimPolicy: Retain
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - kube3
---
#...
</code><code>
kube1:~/pv# kubectl apply -f my-ha-pv.yaml

kube1# kubectl get pv

kube1# kubectl delete pv my-pv-kube3-sz-128m-num-001

kube3# mkdir -p /disk2/dir{0..3}

kube3# chmod 777 -R /disk2/

kube3# find /disk2/

kube3# ###rm -rf /disk2/
</code>

  * [[https://stackoverflow.com/questions/55639436/create-multiple-persistent-volumes-in-one-yaml]]
  * Знакомимся с [[#Helm]]

<code>
kube1:~/pv# cat my-ha-pv-chart/Chart.yaml
</code><code>
apiVersion: v2
name: my-ha-pv-chart
version: 0.1.0
</code><code>
kube1:~/pv# cat my-ha-pv-chart/values.yaml
</code><code>
volume_names:
- "dir1"
- "dir2"
- "dir3"
numVolumes: "3"
</code><code>
kube1:~/pv# cat my-ha-pv-chart/templates/my-ha-pv.yaml
</code><code>
{{ range .Values.volume_names }}
{{/* range $k, $v := until (atoi .Values.numVolumes) */}}
---
apiVersion: v1
kind: PersistentVolume
metadata:
  name: my-pv-sz-128m-num-{{ . }}
spec:
  storageClassName: my-ha-sc
  capacity:
    storage: 128Mi
  accessModes:
    - ReadWriteOnce
  hostPath:
    path: /disk2/{{ . }}/
{{/*    path: /disk2/dir{{ $v }}/ */}}
  persistentVolumeReclaimPolicy: Retain
  nodeAffinity:
    required:
      nodeSelectorTerms:
      - matchExpressions:
        - key: kubernetes.io/hostname
          operator: In
          values:
          - kube3
{{ end }}
</code><code>
kube1:~/pv# helm template my-ha-pv-chart my-ha-pv-chart/

kube1:~/pv# helm install my-ha-pv-chart my-ha-pv-chart/

kube1# kubectl get pv

kube1:~/pv# ###helm uninstall my-ha-pv-chart
</code><code>
kube1:~/pywebd-k8s# cat my-webd-pvc.yaml
</code><code>
apiVersion: v1
kind: PersistentVolumeClaim
metadata:
  name: my-webd-pvc
spec:
  storageClassName: my-ha-sc
  accessModes:
    - ReadWriteOnce
  resources:
    requests:
      storage: 64Mi
</code><code>
kube1:~/pywebd-k8s# kubectl apply -f my-webd-pvc.yaml -n my-ns

kube1:~/pywebd-k8s# kubectl get pvc -n my-ns

kube1:~/pywebd-k8s# cat my-webd-deployment.yaml
</code><code>
...
        volumeMounts:
        - name: htdocs-volume
          mountPath: /usr/local/apache2/htdocs

        lifecycle:
        ...

      volumes:
      - name: htdocs-volume
        persistentVolumeClaim:
          claimName: my-webd-pvc

      initContainers:
      ...
</code><code>
kube3# find /disk2
</code>

=== Dynamic Volume Provisioning ===

  * [[https://kubernetes.io/docs/concepts/storage/dynamic-provisioning/|Dynamic Volume Provisioning]]
  * [[https://kubernetes.io/docs/tasks/administer-cluster/change-default-storage-class/|Changing the default StorageClass]]

=== rancher local-path-provisioner ===

  * [[https://github.com/rancher/local-path-provisioner|rancher local-path-provisioner]]
  * [[https://artifacthub.io/packages/helm/ebrianne/local-path-provisioner|This chart bootstraps a  deployment on a  cluster using the  package manager]]

<code>
$ kubectl apply -f https://raw.githubusercontent.com/rancher/local-path-provisioner/v0.0.26/deploy/local-path-storage.yaml

$ kubectl get sc

$ kubectl -n local-path-storage get all

$ curl https://raw.githubusercontent.com/rancher/local-path-provisioner/v0.0.26/deploy/local-path-storage.yaml | less
/DEFAULT_PATH_FOR_NON_LISTED_NODES

ssh root@kube1 'mkdir /opt/local-path-provisioner'
ssh root@kube2 'mkdir /opt/local-path-provisioner'
ssh root@kube3 'mkdir /opt/local-path-provisioner'
ssh root@kube1 'chmod 777 /opt/local-path-provisioner'
ssh root@kube2 'chmod 777 /opt/local-path-provisioner'
ssh root@kube3 'chmod 777 /opt/local-path-provisioner'

$ ###kubectl patch storageclass local-path -p '{"metadata": {"annotations":{"storageclass.kubernetes.io/is-default-class":"true"}}}'
</code>

  * Сервис Keycloak в [[Сервис Keycloak#Kubernetes]]

<code>
$ kubectl get pvc -n my-keycloak-ns

$ kubectl get pv

$ ###kubectl -n my-keycloak-ns delete pvc data-my-keycloak-postgresql-0
</code>
=== longhorn ===

<code>
kubeN:~# apt install open-iscsi

(venv1) server:~# ansible all -f 4 -m apt -a 'pkg=open-iscsi state=present update_cache=true' -i /root/kubespray/inventory/mycluster/hosts.yaml
</code>
  * [[https://github.com/longhorn/longhorn]]
<code>
$ kubectl apply -f https://raw.githubusercontent.com/longhorn/longhorn/v1.6.0/deploy/longhorn.yaml

$ kubectl -n longhorn-system get pods -o wide --watch

Setting->General

Pod Deletion Policy When Node is Down: delete-statefuset-pod
</code>

Подключение через kubectl proxy

  * [[https://stackoverflow.com/questions/45172008/how-do-i-access-this-kubernetes-service-via-kubectl-proxy|How do I access this Kubernetes service via kubectl proxy?]]

<code>
cmder> kubectl proxy
</code>

  * http://localhost:8001/api/v1/namespaces/longhorn-system/services/longhorn-frontend:80/proxy/

Подключение через ingress

!!! Добавить пример с аутентификацией !!!
<code>
student@server:~/longhorn$ cat ingress.yaml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: longhorn-ingress
  namespace: longhorn-system
spec:
  ingressClassName: nginx
  rules:
  - host: lh.corp13.un
    http:
      paths:
      - backend:
          service:
            name: longhorn-frontend
            port:
              number: 80
        path: /
        pathType: Prefix
</code>

== Использование snapshot-ов ==

  * [[https://github.com/longhorn/longhorn/issues/63?ref=https%3A%2F%2Fgiter.vip|What should be the best procedure to recover a snapshot or a backup in rancher2/longhorn ?]]

  * Делаем снапшот
  * Что-то ломаем (удаляем пользователя)

== Остановка сервиса ==

<code>
kube1:~# kubectl -n my-keycloak-ns scale --replicas 0 statefulset my-keycloak

kube1:~# kubectl -n my-keycloak-ns scale --replicas 0 statefulset my-keycloak-postgresql
</code>

  * Volume -> Attache to Host (любой) в режиме Maintenance, Revert к снапшоту, Deattache 
  * Запускаем сервис

<code>
kube1:~# kubectl -n my-keycloak-ns scale --replicas 1 statefulset my-keycloak-postgresql

kube1:~# kubectl -n my-keycloak-ns scale --replicas 2 statefulset my-keycloak
</code>

== Использование backup-ов ==

  * Разворачиваем [[Сервис NFS]] на server 

<code>
Setting -> General -> Backup Target -> nfs://server.corp13.un:/var/www (nfs client linux не нужен)
</code>
  * Volume -> Create Backup, удаляем NS, восстанавливаем Volume из бекапа, создаем NS и создаем для Volume PV/PVC как было, устанавливаем чарт, он подхватывает pv/pvc

==== ConfigMap, Secret ====

<code>
server# scp /etc/pywebd/* kube1:/tmp/

kube1:~/pywebd-k8s# kubectl create configmap pywebd-conf --from-file=/tmp/pywebd.conf --dry-run=client -o yaml | tee my-webd-configmap.yaml

kube1:~/pywebd-k8s# cat my-webd-configmap.yaml
</code><code>
apiVersion: v1
data:
  pywebd.conf: |
    [default]
    DocumentRoot = /usr/local/apache2/htdocs
    Listen = 4443
kind: ConfigMap
metadata:
  creationTimestamp: null
  name: pywebd-conf
</code><code>
kube1:~/pywebd-k8s# kubectl apply -f my-webd-configmap.yaml -n my-ns

kube1:~/pywebd-k8s# kubectl -n my-ns get configmaps

kube1:~/pywebd-k8s# kubectl create secret tls pywebd-tls --key /tmp/pywebd.key --cert /tmp/pywebd.crt --dry-run=client -o yaml | tee my-webd-secret-tls.yaml

kube1:~/pywebd-k8s# less my-webd-secret-tls.yaml
</code><code>
apiVersion: v1
data:
  tls.crt: ...
  tls.key: ...
kind: Secret
metadata:
  creationTimestamp: null
  name: pywebd-tls
type: kubernetes.io/tls
</code><code>
kube1:~/pywebd-k8s# rm -rv /tmp/pywebd.*

kube1:~/pywebd-k8s# kubectl apply -f my-webd-secret-tls.yaml -n my-ns

kube1:~/pywebd-k8s# kubectl -n my-ns get secrets

kube1:~/pywebd-k8s#  kubectl create secret docker-registry regcred --docker-server=server.corpX.un:5000 --docker-username=student --docker-password='strongpassword' -n my-ns

kube1:~/pywebd-k8s# cat my-webd-deployment.yaml
</code><code>
...
      imagePullSecrets:
      - name: regcred

      containers:
      - name: my-webd
        image: server.corpX.un:5000/student/pywebd:ver1.2
        imagePullPolicy: "Always"

#        env:
#          ...
...
        livenessProbe:
          httpGet:
            port: 4443
            scheme: HTTPS
...
        volumeMounts:
...
        - name: conf-volume
          subPath: pywebd.conf
          mountPath: /etc/pywebd/pywebd.conf
        - name: secret-tls-volume
          subPath: tls.crt
          mountPath: /etc/pywebd/pywebd.crt
        - name: secret-tls-volume
          subPath: tls.key
          mountPath: /etc/pywebd/pywebd.key
...
      volumes:
...
      - name: conf-volume
        configMap:
          name: pywebd-conf
      - name: secret-tls-volume
        secret:
          secretName: pywebd-tls
...
</code><code>
kubeN$ curl --connect-to "":"":<POD_IP>:4443 https://pywebd.corpX.un
</code>

==== ConfigMap ====

  * [[https://www.aquasec.com/cloud-native-academy/kubernetes-101/kubernetes-configmap/|Kubernetes ConfigMap: Creating, Viewing, Consuming & Managing]]
  * [[https://blog.lapw.at/how-to-enable-ssh-into-a-kubernetes-pod/|How to enable SSH connections into a Kubernetes pod]]

<code>
root@node1:~# cat sshd_config
</code><code>
PermitRootLogin yes
PasswordAuthentication no
ChallengeResponseAuthentication no
UsePAM no
</code><code>
root@node1:~# kubectl create configmap ssh-config --from-file=sshd_config --dry-run=client -o yaml
...

server:~# cat .ssh/id_rsa.pub
...

root@node1:~# cat my-openssh-server-deployment.yaml
</code><code>
apiVersion: v1
kind: ConfigMap
metadata:
  name: ssh-config
data:
  sshd_config: |
    PermitRootLogin yes
    PasswordAuthentication no
    ChallengeResponseAuthentication no
    UsePAM no
  authorized_keys: |
    ssh-rsa AAAAB.....C0zOcZ68= root@server.corpX.un
---
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-openssh-server
spec:
  selector:
    matchLabels:
      app: my-openssh-server
  template:
    metadata:
      labels:
        app: my-openssh-server
    spec:
      containers:
      - name: my-openssh-server
        image: linuxserver/openssh-server
        command: ["/bin/sh"]
        args: ["-c", "/usr/bin/ssh-keygen -A; usermod -p '*' root; /usr/sbin/sshd.pam -D"]
        ports:
        - containerPort: 22
        volumeMounts:
        - name: ssh-volume
          subPath: sshd_config
          mountPath: /etc/ssh/sshd_config
        - name: ssh-volume
          subPath: authorized_keys
          mountPath: /root/.ssh/authorized_keys
      volumes:
      - name: ssh-volume
        configMap:
          name: ssh-config
---
apiVersion: v1
kind: Service
metadata:
  name: my-openssh-server
spec:
  type: NodePort
  ports:
  - port: 22
    nodePort: 32222
  selector:
    app: my-openssh-server
</code><code>
root@node1:~# kubectl apply -f my-openssh-server-deployment.yaml

root@node1:~# iptables-save | grep 32222

root@node1:~# ###kubectl exec -ti my-openssh-server-NNNNNNNN-NNNNN -- bash

server:~# ssh -p 32222 nodeN
Welcome to OpenSSH Server
my-openssh-server-NNNNNNNN-NNNNN:~# nslookup my-openssh-server.default.svc.cluster.local
</code>
==== Пример с multi container pod ====

  * [[https://www.mirantis.com/blog/multi-container-pods-and-container-communication-in-kubernetes/|Kubernetes multi-container pods and container communication]]
  * [[https://stackoverflow.com/questions/39979880/kubectl-exec-into-container-of-a-multi-container-pod|kubectl exec into container of a multi container pod]]
  * [[https://betterprogramming.pub/how-to-ssh-into-a-kubernetes-pod-from-outside-the-cluster-354b4056c42b|How to SSH Into a Kubernetes Pod From Outside the Cluster]]
  * [[https://serverfault.com/questions/1013402/is-it-possible-to-expose-2-ports-in-kubernetes-pod|Is it possible to expose 2 ports in Kubernetes pod?]]

<code>
gitlab-runner@gate:~/webd$ cat my-webd-ssh-deployment.yaml
</code><code>
apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-webd-ssh
  namespace: my-ns
spec:
  selector:
    matchLabels:
      app: my-webd-ssh
  replicas: 1
  template:
    metadata:
      labels:
        app: my-webd-ssh
    spec:
      containers:
      - name: my-webd
        image: server.corpX.un:5000/student/webd:latest
        volumeMounts:
        - name: html
          mountPath: /var/www
      - name: my-ssh
        image: atmoz/sftp
        args: ["user3:password3:10003"]
        volumeMounts:
        - name: html
          mountPath: /home/user3/www
      volumes:
      - name: html
        emptyDir: {}
</code><code>
...
$ kubectl describe pod my-webd-NNNNNNNNNN-NNNNN -n my-ns

$ kubectl exec -ti -n my-ns my-webd-NNNNNNNNNN-NNNNN -c my-ssh -- bash

$ ### kubectl expose deployment my-webd-ssh --type=NodePort --port=80,22 -n my-ns

$ cat my-webd-ssh-service.yaml
</code><code>
apiVersion: v1
kind: Service
metadata:
  name: my-webd-ssh
  namespace: my-ns
spec:
  type: NodePort
  selector:
    app: my-webd-ssh
  ports:
  - name: http
    protocol: TCP
    port: 80
    targetPort: 80
  - name: ssh
    protocol: TCP
    port: 22
    targetPort: 22
</code>

===== Helm =====


==== Установка Helm ====

  * [[https://helm.sh/docs/intro/install/|Installing Helm]]
  * [[https://github.com/helm/helm/releases|helm releases]]

<code>
# wget https://get.helm.sh/helm-v3.16.4-linux-amd64.tar.gz

# tar -zxvf helm-*-linux-amd64.tar.gz

# mv linux-amd64/helm /usr/local/bin/helm

$ cat ~/.profile
</code><code>
...
source <(helm completion bash)
</code>

==== Работа с готовыми Charts ====

  * Сервис Keycloak [[Сервис Keycloak#Kubernetes]]

=== ingress-nginx ===

  * [[https://kubernetes.github.io/ingress-nginx/deploy/|NGINX Ingress Controller Installation Guide]]
  * [[https://stackoverflow.com/questions/56915354/how-to-install-nginx-ingress-with-hostnetwork-on-bare-metal|stackoverflow How to install nginx-ingress with hostNetwork on bare-metal?]]
  * [[https://devpress.csdn.net/cloud/62fc8e7e7e66823466190055.html|devpress.csdn.net How to install nginx-ingress with hostNetwork on bare-metal?]]
  * [[https://github.com/kubernetes/ingress-nginx/blob/main/charts/ingress-nginx/values.yaml]]

  * [[https://github.com/kubernetes/ingress-nginx]] --version 4.7.3

<code>
$ helm upgrade ingress-nginx --install ingress-nginx \
--set controller.hostNetwork=true,controller.publishService.enabled=false,controller.kind=DaemonSet,controller.config.use-forwarded-headers=true \
--repo https://kubernetes.github.io/ingress-nginx --namespace ingress-nginx --create-namespace

$ helm list --namespace ingress-nginx
$ helm list -A

$ kubectl get all -n ingress-nginx -o wide

$ helm delete ingress-nginx --namespace ingress-nginx


$ mkdir -p ingress-nginx; cd ingress-nginx

$ helm template ingress-nginx --repo https://kubernetes.github.io/ingress-nginx --namespace ingress-nginx | tee t1.yaml

$ helm show values ingress-nginx --repo https://kubernetes.github.io/ingress-nginx | tee values.yaml.orig

$ cat values.yaml
</code><code>
controller:
  hostNetwork: true
  publishService:
    enabled: false
  kind: DaemonSet
#  config:
#    use-forwarded-headers: true
#    allow-snippet-annotations: true
#  service:
#    type: LoadBalancer
#    loadBalancerIP: "192.168.X.64"
</code><code>
$ helm template ingress-nginx -f values.yaml --repo https://kubernetes.github.io/ingress-nginx -n ingress-nginx | tee t2.yaml

$ helm upgrade ingress-nginx -i ingress-nginx -f values.yaml --repo https://kubernetes.github.io/ingress-nginx -n ingress-nginx --create-namespace

$ kubectl exec -n ingress-nginx pods/ingress-nginx-controller-<TAB> -- cat /etc/nginx/nginx.conf | tee nginx.conf | grep use_forwarded_headers

$ kubectl -n ingress-nginx describe service/ingress-nginx-controller
...
Endpoints:                192.168.X.221:80,192.168.X.222:80,192.168.X.223:80
...

# kubectl get clusterrole -A | grep -i ingress
# kubectl get clusterrolebindings -A | grep -i ingress
# kubectl get validatingwebhookconfigurations -A | grep -i ingress

# ###helm uninstall ingress-nginx -n ingress-nginx
</code>
==== Развертывание своего приложения ====

  * [[https://helm.sh/docs/chart_template_guide/getting_started/|chart_template_guide getting_started]]
  * [[https://opensource.com/article/20/5/helm-charts|How to make a Helm chart in 10 minutes]]
  * [[https://stackoverflow.com/questions/49812830/helm-upgrade-with-same-chart-version-but-different-docker-image-tag|Helm upgrade with same chart version, but different Docker image tag]]
  * [[https://stackoverflow.com/questions/69817305/how-set-field-app-version-in-helm3-chart|how set field app-version in helm3 chart?]]

<code>
~/gowebd-k8s$ helm create webd-chart

$ less webd-chart/templates/deployment.yaml

$ cat webd-chart/Chart.yaml
</code><code>
...
description: A Helm chart WebD for Kubernetes
...
version: 0.1.1
icon: https://val.bmstu.ru/unix/Media/logo.gif
...
appVersion: "latest"
#appVersion: ver1.7   #for vanilla argocd
</code><code>
$ cat webd-chart/values.yaml
</code><code>
...
replicaCount: 2

image:
  repository: server.corpX.un:5000/student/webd
  pullPolicy: Always
...
serviceAccount:
  create: false
...
service:
#  type: NodePort
...
ingress:
  enabled: true
  className: "nginx"
...
  hosts:
    - host: webd.corpX.un
...
#  tls: []
#  tls:
#    - secretName: gowebd-tls
#      hosts:
#        - gowebd.corpX.un
...
#APWEBD_HOSTNAME: "apwebd.corp13.un"
#KEYCLOAK_HOSTNAME: "keycloak.corp13.un"
#REALM_NAME: "corp13"
</code><code>
$ less webd-chart/templates/deployment.yaml
</code><code>
...
          imagePullPolicy: {{ .Values.image.pullPolicy }}
#          env:
#          - name: APWEBD_HOSTNAME
#            value: "{{ .Values.APWEBD_HOSTNAME }}"
#          - name: KEYCLOAK_HOSTNAME
#            value: "{{ .Values.KEYCLOAK_HOSTNAME }}"
#          - name: REALM_NAME
#            value: "{{ .Values.REALM_NAME }}"
...
</code><code>
$ helm lint webd-chart/

$ helm template my-webd webd-chart/ | less

$ helm install my-webd webd-chart/ -n my-ns --create-namespace --wait

$ curl kubeN -H "Host: gowebd.corpX.un"

$ kubectl describe events -n my-ns | less

$ export HELM_NAMESPACE=my-ns

$ helm list

$ ### helm upgrade my-webd webd-chart/ --set=image.tag=ver1.10

$ helm history my-webd

$ helm rollback my-webd 1

$ helm uninstall my-webd
</code>

==== Работа со своим репозиторием ====

  * [[https://docs.gitlab.com/ee/user/packages/helm_repository/|Helm charts in the Package Registry Gitlab]]
  * [[https://github.com/chartmuseum/helm-push/#readme|helm cm-push plugin]]
  * [[https://medium.com/containerum/how-to-make-and-share-your-own-helm-package-50ae40f6c221|How to make and share your own Helm package]]
  * [[https://docs.gitlab.com/ee/user/profile/personal_access_tokens.html|Gitlab Personal access tokens]]
  * [[Инструмент GitLab#Подключение через API]] - Role: Mainteiner, api (read_registry, write_registry не нужно)

=== Добавляем приложение в свой репозиторий ===
<code>
~/gowebd-k8s$ helm repo add --username student --password NNNNN-NNNNNNNNNNNNNNNNNNN webd https://server.corpX.un/api/v4/projects/N/packages/helm/stable
"webd" has been added to your repositories

~/gowebd-k8s$ helm repo list

~/gowebd-k8s$ helm package webd-chart

~/gowebd-k8s$ tar -tf webd-chart-0.1.1.tgz

~/gowebd-k8s$ helm plugin install https://github.com/chartmuseum/helm-push

~/gowebd-k8s$ helm cm-push webd-chart-0.1.1.tgz webd

~/gowebd-k8s$ rm webd-chart-0.1.1.tgz

~/gowebd-k8s$ ### helm repo remove webd

~/gowebd-k8s$ ### helm plugin uninstall cm-push
</code>
=== Устанавливаем приложение через подключение репозитория ===
<code>
kube1:~# helm repo add webd https://server.corpX.un/api/v4/projects/N/packages/helm/stable

kube1:~# helm repo update

kube1:~# helm search repo webd

kube1:~# helm repo update webd

kube1:~# helm show values webd/webd-chart | tee values.yaml.orig

kube1:~# ###helm pull webd/webd-chart

kube1:~# helm install my-webd webd/webd-chart

kube1:~# ###helm uninstall my-webd

kube1:~# ###helm repo remove webd
</code>
=== Устанавливаем приложение без подключение репозитория ===
<code>
kube1:~# mkdir gowebd; cd gowebd

kube1:~/gowebd# ###helm pull webd-chart --repo https://server.corpX.un/api/v4/projects/N/packages/helm/stable

kube1:~/gowebd# helm show values webd-chart --repo https://server.corpX.un/api/v4/projects/N/packages/helm/stable | tee values.yaml.orig

kube1:~/gowebd# cat values.yaml
</code><code>
replicaCount: 3
image:
  tag: "ver1.1"
#REALM_NAME: "corp"
</code><code>
kube1:~/gowebd# helm upgrade my-webd -i webd-chart -f values.yaml -n my-ns --create-namespace --repo https://server.corpX.un/api/v4/projects/N/packages/helm/stable

$ curl http://kubeN -H "Host: gowebd.corpX.un"

kube1:~/gowebd# ###helm uninstall my-webd -n my-ns
</code>

==== Работа с публичными репозиториями ====

=== gitlab-runner kubernetes ===

<code>
kube1:~/gitlab-runner# kubectl create ns gitlab-runner

kube1:~/gitlab-runner# kubectl -n gitlab-runner create configmap ca-crt --from-file=/usr/local/share/ca-certificates/ca.crt

kube1:~/gitlab-runner# helm repo add gitlab https://charts.gitlab.io

kube1:~/gitlab-runner# helm repo list

kube1:~/gitlab-runner# helm search repo -l gitlab

kube1:~/gitlab-runner# helm search repo -l gitlab/gitlab-runner

kube1:~/gitlab-runner# helm show values gitlab/gitlab-runner --version 0.70.5 | tee values.yaml

kube1:~/gitlab-runner# cat values.yaml
</code><code>
...
gitlabUrl: https://server.corpX.un
...
runnerToken: "NNNNNNNNNNNNNNNNNNNNN"
...
rbac:
...
  create: true                      #change this
...
serviceAccount:
...
  create: true                      #change this
...
runners:
...
  config: |
    [[runners]]
      tls-ca-file = "/mnt/ca.crt"   #insert this
      [runners.kubernetes]
        namespace = "{{.Release.Namespace}}"
        image = "alpine"
        privileged = true           #insert this
...
securityContext:
  allowPrivilegeEscalation: true    #change this
  readOnlyRootFilesystem: false
  runAsNonRoot: true
  privileged: true                  #change this
...
#volumeMounts: []                   #comment this
volumeMounts:
  - name: ca-crt
    subPath: ca.crt
    mountPath: /mnt/ca.crt
...
#volumes: []                        #comment this
volumes:
  - name: ca-crt
    configMap:
      name: ca-crt
...
</code><code>
kube1:~/gitlab-runner# helm upgrade -i gitlab-runner gitlab/gitlab-runner -f values.yaml -n gitlab-runner --version 0.70.5

kube1:~/gitlab-runner# kubectl get all -n gitlab-runner

kube1:~/gitlab-runner# ### helm -n gitlab-runner uninstall gitlab-runner
</code>

== старая версия ==
<code>
gitlab-runner@server:~$ helm repo add gitlab https://charts.gitlab.io

gitlab-runner@server:~$ helm repo list

gitlab-runner@server:~$ helm search repo -l gitlab

gitlab-runner@server:~$ helm search repo -l gitlab/gitlab-runner

gitlab-runner@server:~$ helm show values gitlab/gitlab-runner --version 0.56.0 | tee values.yaml

gitlab-runner@server:~$ diff values.yaml values.yaml.orig
</code><code>
...
gitlabUrl: http://server.corpX.un/
...
runnerRegistrationToken: "NNNNNNNNNNNNNNNNNNNNNNNN"
...
148,149c142
<   create: true
---
>   create: false
325d317
<         privileged = true
432c424
<   allowPrivilegeEscalation: true
---
>   allowPrivilegeEscalation: false
435c427
<   privileged: true
---
>   privileged: false
</code><code>
gitlab-runner@server:~$ helm upgrade -i gitlab-runner gitlab/gitlab-runner -f values.yaml -n gitlab-runner --create-namespace --version 0.56.0

gitlab-runner@server:~$ kubectl get all -n gitlab-runner
</code>

== SSL/TLS ==

<code>
# kubectl -n gitlab-runner create configmap wild-crt --from-file=wild.crt

# cat values.yaml
</code><code>
...
gitlabUrl: https://server.corpX.un/
...
  config: |
    [[runners]]
      tls-ca-file = "/mnt/wild.crt"
      [runners.kubernetes]      
...
#volumeMounts: []
volumeMounts:
  - name: wild-crt
    subPath: wild.crt
    mountPath: /mnt/wild.crt
    
#volumes: []
volumes:
  - name: wild-crt
    configMap:
      name: wild-crt
</code>

===== Kubernetes Dashboard =====

  * https://www.bytebase.com/blog/top-open-source-kubernetes-dashboard/

  * https://kubernetes.io/docs/tasks/access-application-cluster/web-ui-dashboard/
  * https://github.com/kubernetes/dashboard/blob/master/docs/user/access-control/creating-sample-user.md

  * [[https://kubernetes.io/docs/reference/kubectl/generated/kubectl_create/kubectl_create_token/]]
  * [[https://www.jwt.io/|JSON Web Token (JWT) Debugger]]

<code>
$ kubectl apply -f https://raw.githubusercontent.com/kubernetes/dashboard/v2.7.0/aio/deploy/recommended.yaml

$ cat dashboard-user-role.yaml
</code><code>
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: admin-user
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: cluster-admin
subjects:
- kind: ServiceAccount
  name: admin-user
  namespace: kubernetes-dashboard
---
apiVersion: v1
kind: Secret
metadata:
  name: admin-user
  namespace: kubernetes-dashboard
  annotations:
    kubernetes.io/service-account.name: "admin-user"
type: kubernetes.io/service-account-token
</code><code>
$ kubectl apply -f dashboard-user-role.yaml

$ kubectl -n kubernetes-dashboard create token admin-user #--duration=1h

$ ###ps aux | grep kube-apiserver | grep service-account-key-file

$ kubectl get secret admin-user -n kubernetes-dashboard -o jsonpath={".data.token"} | base64 -d ; echo

cmder$ kubectl proxy
</code>

  * http://localhost:8001/api/v1/namespaces/kubernetes-dashboard/services/https:kubernetes-dashboard:/proxy/

===== Мониторинг =====

==== Metrics Server ====

  * [[https://kubernetes-sigs.github.io/metrics-server/Kubernetes Metrics Server]]
  * [[https://medium.com/@cloudspinx/fix-error-metrics-api-not-available-in-kubernetes-aa10766e1c2f|Fix “error: Metrics API not available” in Kubernetes]]

<code>
kube1:~/metrics-server# curl -L https://github.com/kubernetes-sigs/metrics-server/releases/download/v0.7.2/components.yaml | tee metrics-server-components.yaml

kube1:~/metrics-server# cat metrics-server-components.yaml
</code><code>
...
      containers:
      - args:
        - --cert-dir=/tmp
        - --kubelet-insecure-tls   # add this
...
</code><code>
kube1:~/metrics-server# kubectl apply -f metrics-server-components.yaml

kube1# kubectl get pods -A | grep metrics-server

kube1# kubectl top pod #-n kube-system

kube1# kubectl top pod -A --sort-by=memory

kube1# kubectl top node
</code>

==== kube-state-metrics ====

  * [[https://github.com/prometheus-community/helm-charts/tree/main/charts/kube-state-metrics]]
  * ... алерты с инфой по упавшим подам ...

<code>
kube1# helm repo add prometheus-community https://prometheus-community.github.io/helm-charts

kube1# helm repo update
kube1# helm install kube-state-metrics prometheus-community/kube-state-metrics -n vm --create-namespace

kube1# curl kube-state-metrics.vm.svc.cluster.local:8080/metrics
</code>
===== Отладка, troubleshooting =====

==== Отладка etcd ====

  * [[https://sysdig.com/blog/monitor-etcd/|How to monitor etcd]]

<code>
kubeN:~# more /etc/kubernetes/manifests/kube-apiserver.yaml

kubeN:~# etcdctl member list -w table \
  --endpoints=https://kube1:2379 \
  --cacert=/etc/ssl/etcd/ssl/ca.pem \
  --cert=/etc/ssl/etcd/ssl/node-kube1.pem \
  --key=/etc/ssl/etcd/ssl/node-kube1-key.pem

kubeN:~# etcdctl endpoint status -w table \
  --endpoints=https://kube1:2379,https://kube2:2379,https://kube3:2379 \
  --cacert=/etc/ssl/etcd/ssl/ca.pem \
  --cert=/etc/ssl/etcd/ssl/node-kube1.pem \
  --key=/etc/ssl/etcd/ssl/node-kube1-key.pem
</code>
===== Дополнительные материалы =====

==== Настройка registry-mirrors для Kubespray ====
<code>
~/kubespray# cat inventory/mycluster/group_vars/all/docker.yml
</code><code>
...
docker_registry_mirrors:
  - https://mirror.gcr.io
...
</code><code>
~/kubespray# cat inventory/mycluster/group_vars/all/containerd.yml
</code><code>
...
containerd_registries_mirrors:
  - prefix: docker.io
    mirrors:
    - host: https://mirror.gcr.io
      capabilities: ["pull", "resolve"]
      skip_verify: false
...
</code>

==== Установка kubelet kubeadm kubectl в ubuntu20 ====

  * На каждом узле нужно сделать

<code>
mkdir /etc/apt/keyrings

curl -fsSL https://pkgs.k8s.io/core:/stable:/v1.28/deb/Release.key | sudo gpg --dearmor -o /etc/apt/keyrings/kubernetes-apt-keyring.gpg

echo 'deb [signed-by=/etc/apt/keyrings/kubernetes-apt-keyring.gpg] https://pkgs.k8s.io/core:/stable:/v1.28/deb/ /' | sudo tee /etc/apt/sources.list.d/kubernetes.list

apt update && apt install -y kubeadm=1.28.1-1.1 kubelet=1.28.1-1.1 kubectl=1.28.1-1.1
</code>

==== Use .kube/config Client certs in curl ====
  * [[https://serverfault.com/questions/1094361/use-kube-config-client-certs-in-curl|Use .kube/config Client certs in curl]]
<code>
cat ~/.kube/config | yq -r '.clusters[0].cluster."certificate-authority-data"' | base64 -d - > ~/.kube/ca.pem 
cat ~/.kube/config | yq -r '.users[0].user."client-certificate-data"' | base64 -d - > ~/.kube/user.pem
cat ~/.kube/config | yq -r '.users[0].user."client-key-data"' | base64 -d - > ~/.kube/user-key.pem

SERVER_URL=$(cat ~/.kube/config | yq -r .clusters[0].cluster.server)

curl --cacert ~/.kube/ca.pem --cert ~/.kube/user.pem --key ~/.kube/user-key.pem -X GET  ${SERVER_URL}/api/v1/namespaces/default/pods/
</code>

==== bare-metal minikube ====

<code>
student@node2:~$ sudo apt install conntrack

https://computingforgeeks.com/install-mirantis-cri-dockerd-as-docker-engine-shim-for-kubernetes/
...

wget https://github.com/kubernetes-sigs/cri-tools/releases/download/v1.24.2/crictl-v1.24.2-linux-amd64.tar.gz
...

student@node2:~$ minikube start --driver=none --insecure-registry "server.corpX.un:5000"
</code>

==== minikube dashboard ====
<code>
student@node1:~$ minikube dashboard &
...
Opening http://127.0.0.1:NNNNN/api/v1/namespaces/kubernetes-dashboard/services/http:kubernetes-dashboard:/proxy/ in your default browser
...
/home/mobaxterm> ssh -L NNNNN:localhost:NNNNN student@192.168.X.10
Теперь, та же ссылка работает на win host системе
</code>

==== Подключение к minikube с другой системы ====

  * Если не minikube, то достаточно только копию .kube/config
  * [[https://habr.com/ru/company/flant/blog/345580/|см. Настройка GitLab Runner]]

<code>
student@node1:~$ tar -cvzf kube-config.tar.gz .kube/config .minikube/ca.crt .minikube/profiles/minikube

gitlab-runner@server:~$ scp student@node1:kube-config.tar.gz .

gitlab-runner@server:~$ tar -xvf kube-config.tar.gz

gitlab-runner@server:~$ cat .kube/config
</code><code>
...
    certificate-authority: /home/gitlab-runner/.minikube/ca.crt
...
    client-certificate: /home/gitlab-runner/.minikube/profiles/minikube/client.crt
    client-key: /home/gitlab-runner/.minikube/profiles/minikube/client.key
...
</code>
==== kompose ====

  * [[https://stackoverflow.com/questions/47536536/whats-the-difference-between-docker-compose-and-kubernetes|What's the difference between Docker Compose and Kubernetes?]]
  * [[https://loft.sh/blog/docker-compose-to-kubernetes-step-by-step-migration/|Docker Compose to Kubernetes: Step-by-Step Migration]]
  * [[https://kubernetes.io/docs/tasks/configure-pod-container/translate-compose-kubernetes/|Translate a Docker Compose File to Kubernetes Resources]]

<code>
root@gate:~# curl -L https://github.com/kubernetes/kompose/releases/download/v1.26.0/kompose-linux-amd64 -o kompose
root@gate:~# chmod +x kompose
root@gate:~# sudo mv ./kompose /usr/local/bin/kompose
</code>

  * [[Технология Docker#docker-compose]]
<code>
gitlab-runner@gate:~/webd$ kompose convert
gitlab-runner@gate:~/webd$ ls *yaml
gitlab-runner@gate:~/webd$ kubectl apply -f sftp-deployment.yaml,vol1-persistentvolumeclaim.yaml,webd-service.yaml,sftp-service.yaml,webd-deployment.yaml
gitlab-runner@gate:~/webd$ kubectl get all
</code>
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