Symfony ❤︎ K8S

Who am I?

Kubernetes: where it came from

Inspired by Google's Borg project (C++) https://en.wikipedia.org/wiki/Kubernetes#History

Kubernetes: basic structure

• Master node(s)
  etcd, API server, scheduler, controller manager
• Worker nodes
  kubelet, Kube-proxy & container runtime
• kubectl
  Installation: https://kubernetes.io/docs/tasks/tools/install-kubectl/

Main resources

Ingress

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: my-sf-demo
spec:
  rules:
    - host: my-sf-demo.alessandrolai.dev
      http:
        paths:
          - path: /
            backend:
              serviceName: nginx
              servicePort: 80
  tls:
    - hosts:
        - my-sf-demo.alessandrolai.dev

Service

apiVersion: v1
kind: Service
metadata:
  name: nginx
spec:
  ports:
    - port: 80
  selector:
    app: my-sf-demo
    tier: php

Deployment

apiVersion: apps/v1
kind: Deployment
metadata:
  name: php
spec:
  replicas: 2
  template:
    spec:
      containers:
      - image: docker.facile.it/facile/my-sf-demo-nginx:prod
        name: nginx
        ports:
        - containerPort: 80
      - image: docker.facile.it/facile/my-sf-demo-php:prod
        name: php
        env:
          - name: DATABASE_PASSWORD
            valueFrom:
              secretKeyRef:
                name: my-database
                key: password

Cron

apiVersion: batch/v1beta1
kind: CronJob
metadata:
  name: prod-cron-hello-world
spec:
  schedule: "0 23 * * *"
  suspend: false
  successfulJobsHistoryLimit: 3
  jobTemplate:
  template:
    spec:
      template:
        spec:
          containers:
          - image: docker.facile.it/facile/my-sf-demo-nginx:prod
            name: nginx
            ports:
            - containerPort: 80
          - image: docker.facile.it/facile/my-sf-demo-php:prod
            name: php
            env:
              - name: DATABASE_PASSWORD
                valueFrom:
                  secretKeyRef:
                    name: my-database
                    key: password

Objective: CI/CD pipeline

Last year's talk - Video

Deploy (?)

Deploy:
  stage: Deploy
  script:
  - kubectl set image deployment/very-simple-app php=$PHP_IMAGE 
  - kubectl rollout status deployment/very-simple-app
  only:
  - master

Result:

$ kubectl set image deployment/very-simple-app php="${!PHP_IMAGE_VAR}"
deployment "very-simple-app" images updated

$ kubectl rollout status deployment/very-simple-app
Waiting for rollout to finish: 1 old replicas are pending termination...
Waiting for rollout to finish: 1 old replicas are pending termination...
Waiting for rollout to finish: 5 of 6 updated replicas are available...
deployment "very-simple-app" successfully rolled out

What Helm does:

• Templating
• Package manager (charts)
• Deployer

Demo!

Chart folder

Template example

{{- $host := $.Values.app.url | trimPrefix "https://" | quote -}}

apiVersion: extensions/v1beta1
kind: Ingress
metadata:
  name: {{ $.Values.app.name }}-ingress
spec:
  rules:
    - host: {{ $host }}
      http:
        paths:
          - path: /
            backend:
              serviceName: {{ $.Values.nginx.name }}
              servicePort: {{ $.Values.nginx.port }}
  tls:
    - hosts:
        - {{ $host }}

values.yaml

app:
  name: sfday-demo
  env: ~
  url: ~

nginx:
  port: 80
  name: nginx
  image: ~
  resources:
    requests:
      memory: 16M
      cpu: 10m
    limits:
      memory: 32M
      cpu: 50m
php:
  name: php
  image: ~
  replicas: 2
  resources:
    requests:
      memory: 63M
      cpu: 25m
    limits:
      memory: 128M
      cpu: 250m

Local dump/test

helm-template: helm-template-prod helm-template-staging

helm-template-prod:
  rm -rf k8s/prod/*
  @docker-compose run --rm helm /bin/sh -c "
    helm template /var/www/sfday/charts/SFday-demo/ \
      --output-dir /var/www/sfday/k8s/prod \
      --set app.env=prod \
      --set app.tag=prod-abcd1234 \
      --set app.url=https://prod.example.com/ \
      --set gitlabRegistrySecret=secret-sfday-prod \
      --set php.image=registry.com/myproject/php \
      --set nginx.image=registry.com/myproject/nginx"

helm-template-staging:
  rm -rf k8s/staging/*
  @docker-compose run --rm helm /bin/sh -c "
    helm template /var/www/sfday/charts/SFday-demo/ \
      --output-dir /var/www/sfday/k8s/staging \
      --set app.env=staging \
      --set app.tag=staging-abcd1234 \
      --set app.url=https://staging.example.com/ \
      --set gitlabRegistrySecret=secret-sfday-staging \
      --set php.image=registry.com/myproject/php \
      --set nginx.image=registry.com/myproject/nginx"

Helm in action

.helm_job:
  image: $CI_REGISTRY_IMAGE/helm:2.14.3
  before_script: []
  cache: {}
  services: []

.deploy_template:
  stage: Deploy
  extends: .helm_job
  script:
    - >
      helm init \
        --upgrade \
        --wait \
        --tiller-namespace="$KUBE_NAMESPACE"
    - >
      helm upgrade \
        --install \
        --atomic \
        --namespace="$KUBE_NAMESPACE" \
        --tiller-namespace="$KUBE_NAMESPACE" \
        --set app.env="$CI_ENVIRONMENT_SLUG" \
        --set app.tag="$APP_ENV-$CI_COMMIT_SHORT_SHA" \
        --set app.url="$CI_ENVIRONMENT_URL" \
        --set gitlabRegistrySecret="gitlab-docker-registry" \
        --set php.image=$PHP_IMAGE \
        --set nginx.image=$NGINX_IMAGE \
        --set dockerRegistry="$CI_REGISTRY_IMAGE" \
        "sfday-demo-$CI_ENVIRONMENT_SLUG" \
        charts/SFday-demo/

...and now, dynamic review environments!

Deploy review:
  extends:
    - .deploy_template
    - .review_template
  variables:
    APP_ENV: review
  environment:
    url: http://$CI_ENVIRONMENT_SLUG.sfday.demo/
    on_stop: Stop review

Stop review:
  stage: Stop
  when: manual
  extends:
    - .review_template
    - .helm_job
  environment:
    action: stop
  script:
    - >
      helm delete \
        --tiller-namespace="$KUBE_NAMESPACE" \
        "sfday-demo-$CI_ENVIRONMENT_NAME"

Questions?

References

• Demo repository with CI/CD pipelines
• kubectl installation
  (remember to install autocomplete too!)
• K8s docs
• K8s API reference
• Helm docs
• Sprig (Go Template) docs
• GitLab CI docs

Please rate my talk on Joind.in:
https://joind.in/talk/910a4

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