GitHub Action for deploy Pull Requests in Google Kubernetes Service for Moleculer App

Description

A Github Action to deploy previews of Pull Requests to GKE via Moleculer Helm Package 🚀

Deploy previews

• build docker image + tag with meta preview tags
• publish docker image to container registry
• create an external IP address
• create a DNS.
• deploy chart / preview in Kubernetes
• add a preview comment to pull request with link to preview

Prerequisite

This action is (currently) tightly coupled to the following set of tools.

• Kubernetes cluster (GKE)
• GCP token for authentication
• google registery as container registry (could work with others, but not tested)
• Domain zone hosted on Google cloud
• Moleculer app
• Dockerfile for the application

Example deployment

name: "deploy-pr"
on:
  pull_request:
    types: [opened, edited, reopened, synchronize]
  
jobs:
  hello_world_job:
    runs-on: ubuntu-latest
    name: deploy-pr
    steps:
      - uses: knawat/github-actions-deploy-moleculer@main
        with: 
          #APPLICATION VARIABLE
          SERVICES: {api,products}
          SERVICEDIR: build/services
          MOLECULER_APM_ENABLE: 1
          AGENT_TOKEN: ${{ secrets.AGENT_TOKEN }}
          AGENT_APIKEY: ${{ secrets.AGENT_APIKEY }}
          TRANSPORTER: tcp
          MONGO_URI: '${{ secrets.MONGO_URI }}' //should include it between ''
          BASE_URL: api.example.com //The gateway URL of your app, the deployment PR URL will be 'pr-[PR_NUMBER].[BASE_URL]'
          HELM_SET: ${{ secrets.HELM_SET }} //To include any other application env var (environment.env.VAR1=VAL1)
          # GCP Configuration 
          DNS_ZONE_NAME: 'EXAMPLE-COM' //It's the cloud DNS Zone name not the DNS name (P.S. DNS name is example.com)
          GCP_PROJECT: 'example-project'
          GCP_JSON_KEY: ${{ secrets.GCP_JSON_KEY }}
          #DOCKER CONFIGURATION
          DOCKER_REGISTRY: 'gcr.io'
          IMAGE_REPO_NAME: 'api'
          IMAGE_TAGS: "$GITHUB_SHA" 
          #K8S Configuration
          CLUSTER_NAME: "cluster-dev"
          CLUSTER_LOCATION: "us-central1-c"
          CONTAINER_NAME: "app"
          #GitHub Configuration
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

Usage

If the SERVICES conatins API service, it will create:

1. External IP: "RepoName"-"PR_Number"-pr so, for example: I'm working on a repo name: "knawat/app" and I created a PR (263), the IP will create with the following name: app-263-pr
2. DNS: pr-"PR_Number"."BASE_URL" so, if I set the BASE_URL=api.knawat.io in the env, the DNS will create with the following name: pr-263.api.knawat.io and it's point to the previous IP address.
3. For moleculer helm package will create the ingress.

If you need to add environment variables to your application you can use HELM_SET variable:

 with: 
     HELM_SET: environment.env.VAR1=VAL1,environment.env.VAR2=VAL2

If you need to enable molecler Lab:

 with: 
     MOLECULER_APM_ENABLE: 1
     AGENT_TOKEN: YourApiToken
     AGENT_APIKEY: YourApiKey

If you need to change the transporter use by the application:

 with: 
     TRANSPORTER: nats://nats:4222

Configuration

Variable	Description	Default value	Required
HELM_RELEASE_NAME	The helm release name to deploy.	[REPO_NAME]-[PR_Number]-pr	NO
HELM_RELEASE_NAMESPACE	The namespace of helm release, in which k8s namespace. It will create a new one if not exists.	[REPO_NAME]-[PR_Number]-pr	NO
DOCKER_FILE	The location of your docker file to build the image, usually it's in the root directory of your application.	Dockerfile	NO
DOCKER_REGISTRY	Docker image registry. where you want to save your build image. Defaults to GCP container registry	gcr.io	YES
IMAGE_REPO_NAME	Image repo name in the image registery	myImageRepo	YES
IMAGE_TAGS	Your build image tag. it's good to use $GITHUB_SHA	latest	NO
CONTAINER_NAME	The container name that should deploy to the k8s cluster	myApp	NO
TRANSPORTER	he transporter for the moleculer application	tcp	NO
SERVICES	The name of the moleculer services you want to deploy, it should between {}	''	NO
SERVICEDIR	The name of the moleculer services directory	build/services	NO
MONGO_URI	The DB connection string	''	YES
BASE_URL	Your app base URL,Let's assume that your app gateway URL is 'api.example.com', and you want to create a PR deployment using this action, so the deployment PR URL will be 'pr-[PR_NUMBER].[BASE_URL]' (pr-1.api.example.com)	api.example.com	YES
CRON_ENABLED	If you have a cron in your application and you want to add it to moleculer helm package, you can enable it here and add it's configuration in HELM_SET.	false	NO
LABORATORY_ENABLED	If you don't have the lab service installed in your app, you should disable this option to not installing the lab service in k8s.	true	NO
INGRESS_ENABLED	If you don't have the api gateway service in your app, you should disable this to aviod install the api service in k8s and avoid install the ingress.	true	NO
MOLECULER_APM_ENABLE	The moleculer laboratory for your application.	0	NO
AGENT_TOKEN	The moleculer lab agent token for the moleculer laboratory.	someSecret	NO
AGENT_APIKEY	The moleculer lab API key for the moleculer laboratory	someSecret	NO
HELM_SET	Additional helm values to set environment variables (corresponds to helm upgrade --set). Should have format environment.env.VAR1=VAL1,environment.env.VAR2=VAL2.		NO
GCP_PROJECT	The ID of your project on Google Cloud.	example-project	YES
PORTGCP_JSON_KEY	The auth token to authenticate with your GCloud Project.		YES
CLUSTER_NAME	The K8S cluster name.	example-cluster	YES
CLUSTER_LOCATION	The K8S cluster location on GCP.	us-central-01	YES
DNS_ZONE_NAME	Your DNS Zone Name in GCP Cloud DNS,It's the cloud DNS Zone name not the DNS name (P.S. DNS name is example.com)"	xample-com	YES
GITHUB_TOKEN	Your GitHub token, you can get it from this GitHub environment variable ${{ secrets.GITHUB_TOKEN }} by default.		YES

Output Variables

Variable	Description	Value
HELM_NOTE	The helm release notes.	Release Name, Last Deployed, Namespace, Status, Revision, Test Suite, Notes
LAB_IP_ADDRESS	The namespace of helm release, in which k8s namespace. It will create a new one if not exists.	IP Address

Default environment variables of moleculer helm package

Variable	Default Value
NODE_ENV	development
PORT	3000
LOGGER	Laboratory
LOGLEVEL	info
CACHER	memory

For reference you can visit the helm package repo from here.