Deploy Rails App to Gcloud

Deploy a sample Rails application to Gcloud using k8s and kubernetes_helper gem.

Create a sample rails app

rails new sample_k8s
cd sample_k8s

• Add sample message
  • add root 'application#hello' to config/routes.rb
  • add the following to app/controllers/application.rb

      def hello
        render inline: 'Hello world'
      end  
    

    

• Start server: rails s -e prodution
• Visit http://localhost:3000

Prepare application for k8s

• Add Dockerfile to define app dependencies in a container
• Add .dockerignore to exclude unnecessary files like node_modules
• Test container: docker build .
• Create project on gcloud: https://console.cloud.google.com
• Enable kubernetes engine by navigating to: https://console.cloud.google.com/kubernetes/list
• Install k8s helper: gem install kubernetes_helper -v '~>1.0'

Setup application in k8s (Following .kubernetes/readme.md instructions)

• Create project on gcloud
  https://console.cloud.google.com

• Enable kubernetes engine by navigating to: https://console.cloud.google.com/kubernetes/list

• Login gcloud: gcloud auth login
• Connect project: gcloud config set project my-project
• Create cluster: gcloud container clusters create my-cluster --preemptible

• Connect cluster: gcloud container clusters get-credentials my-cluster --zone europe-west4-a

• Edit .kubernetes/settings.rb (Step #6 from .kubernetes/readme.md)
  Changed: app_name = is_production ? ‘sample_k8s’ : ‘sample_k8s_beta’
  Changed: command: ‘rails s’
  Make cloud_secret_name: nil # for now using default sqlite instead of gcloud sql (mysql or postgres)
  Set gcloud settings in continuous_deployment{…}

• Skip step #7 (using sqlite for testing purpose)

• Register app secrets (rails_env = “production” 64 base encoded)
  Edit secrets.yml DEPLOY_ENV=beta kubernetes_helper run_yml 'secrets.yml' 'kubectl create'

• Create application pods: DEPLOY_ENV=beta kubernetes_helper run_yml 'deployment.yml' 'kubectl create'

  kubectl get pod
  ==> sample-k8s-beta-748f5546-9scb7              1/2     ImagePullBackOff   0          12s
  

  “ImagePullBackOff” is because app container is missing.

• Create service: DEPLOY_ENV=beta kubernetes_helper run_yml 'service.yml' 'kubectl create'

• Reserve a static ip address:
  DEPLOY_ENV=beta kubernetes_helper run_command "gcloud compute addresses create <%=ingress.ip_name%> --global"

  gcloud compute addresses list
  ==> sample-k8s-beta-static-ip        35.227.200.216  EXTERNAL RESERVED
  

• Register ingress to receive http calls
  DEPLOY_ENV=beta kubernetes_helper run_yml 'ingress.yml' 'kubectl create'

  kubectl get ingress
  ==> sample-k8s-beta-ingress        <none>   *   80      6s
  

• Deploy application container

  DEPLOY_ENV=beta kubernetes_helper run_deployment 'cd.sh'
  

  

  kubectl get pod
  ==> sample-k8s-beta-ff6d794dc-nccm9             2/2     Running       0          26s
  

• Visit application by the generated ip (http://35.227.200.216)

Extra steps

• Setup domain name (Step #12)
  • Visit your domain manager and point your domain or subdomain to the reserved ip: 35.227.200.216
  • Edit .kubernetes/settings.rb to set your domain name
  • Update ingress DEPLOY_ENV=beta kubernetes_helper run_yml 'ingress.yml' 'kubectl apply'
  • Visit your domain (depends on your provider can take more than 15 minutes to propagate ssl and domain name)
• Replace sqlite into Cloud sql
  • Create your database on cloud sql
  • Set your configurations in secrets.yml
  • Set your cloud sql info in cloud_sql_instance and cloud_secret_name
  • Download your cloudsql credentials from https://console.cloud.google.com/iam-admin/iam
  • Register secrets on k8s: DEPLOY_ENV=beta kubernetes_helper run_command "kubectl create secret generic <%=deployment.cloud_secret_name%> --from-file=credentials.json=<path-to-downloaded/credentials.json>"
  • Apply secret changes: DEPLOY_ENV=beta kubernetes_helper run_yml 'secrets.yml' 'kubectl apply'
  • Apply deployment changes: DEPLOY_ENV=beta kubernetes_helper run_yml 'deployment.yml' 'kubectl apply'
• Run sidekiq service
  • Edit settings.rb and set the correct values for job_name, job_command, job_services
  • Apply deployment changes: DEPLOY_ENV=beta kubernetes_helper run_yml 'deployment.yml' 'kubectl apply'
  • List pods:

    kubectl get pod
    ==>
    sample-k8s-beta-748f5546-tj59k              2/2     Running       0          5s
    sample-k8s-beta-job-78c9c64f6-pd6cf         1/2     Running         0          4s