Run HTTP Server as systemd process and automate it with github actions

Quick demo

Step 1: Create a HTTP server or any long running process.

• Initialize node project npm init -y

• Install dependencies npm install expres

• Create index.js with following content

const express = require('express')
const app = express()
const port = 3000

app.get('/', (req, res) => {
  res.send('Hello World!')
})

app.listen(port, () => {
  console.log(`Example app listening at <http://localhost>:${port}`)
})

• Add start script in package.json, scripts section

 "start": "node index.js"

• Run npm start from the terminal & verify if the app is running or not.

Step 2: Create a virtual linux machine

• Setup Virtual Machine For Google cloud users following is the command to create vm instance.

Note: Replace the PROJECT_NAME, SERVICE_ACCOUNT with your google cloud project and service accounts. Also you can set different machine type based on your traffic and processing.

gcloud beta compute --project=PROJECT_NAME instances create my-server --zone=us-central1-a --machine-type=e2-micro --subnet=default --network-tier=PREMIUM --maintenance-policy=MIGRATE --service-account=SERVICE_ACCOUNT --scopes=https://www.googleapis.com/auth/devstorage.read_only,<https://www.googleapis.com/auth/logging.write,https://www.googleapis.com/auth/monitoring.write,https://www.googleapis.com/auth/servicecontrol,https://www.googleapis.com/auth/service.management.readonly,https://www.googleapis.com/auth/trace.append> --tags=http-server,https-server --image=debian-10-buster-v20210512 --image-project=debian-cloud --boot-disk-size=10GB --boot-disk-type=pd-balanced --boot-disk-device-name=my-server --no-shielded-secure-boot --shielded-vtpm --shielded-integrity-monitoring --reservation-affinity=any

• Enable requests on port 3000 for this instance

Note: for the demo purpose I am enabling port 3000 on all the instances in my Google account

gcloud compute --project=PROJECT_NAME firewall-rules create port-3000 --direction=INGRESS --priority=1000 --network=default --action=ALLOW --rules=tcp:3000 --source-ranges=0.0.0.0/0

• ssh into the newly created VM

gcloud beta compute ssh --zone=us-central1-a "my-server"  --project=PROJECT_NAME

• Install NodeJS

sudo apt-get update
curl -fsSL <https://deb.nodesource.com/setup_16.x> | sudo -E bash -
sudo apt-get install -y nodejs

• Install wget for downloading source files

sudo apt-get install -y wget

• Install unzip for extracting source

sudo apt-get install -y unzip

Step 3: Release the basic version and test the app

• Download the zip from github

wget <https://github.com/lakhansamani/deployment-automation-demo/archive/refs/heads/main.zip>

• Unzip the source

unzip main.zip

• Install dependenceis

mv deployment-automation-demo-main demo && cd demo
npm install

• Start node server

npm start

• Open the instance IP:3000 in your browser and you will see Hello World

Step 4: Create systemd configuration file

Note: Change service name, path to source and working directory.

[Unit]
Description=demo

[Service]
Type=simple
Restart=always
RestartSec=5
ExecStart=/usr/bin/node /home/YOUR_SSH_USERNAME/demo/index.js
WorkingDirectory=/home/YOUR_SSH_USERNAME/demo/

[Install]
WantedBy=multi-user.target

Step 5: Create shell script to deploy the latest release

• Download the source based on release tag

• Install the node dependencies

• Start/Restart the systemd service

Note: Please change github path, repo name while unzipping it and service in the file below

#!/bin/sh
if [ "$1" == "" ]; then
    echo "Please enter version"
    exit 1
fi

echo "upgrading demo to v-${1}"

# for private repos you can use wget with GithubToken in header
# example --header "Authorization: token ${GITHUB_TOKEN}"

wget <https://github.com/lakhansamani/deployment-automation-demo/archive/refs/tags/${1}.zip> -O demo.zip

# unzip
unzip demo.zip
mkdir -p demo
cp deployment-automation-demo-${1}/* demo/
rm -rf deployment-automation-demo-${1} demo.zip
cd demo
npm install

# Copy service file, incase if there are any changes
sudo cp demo.service /etc/systemd/system/demo.service
# reload configurations incase if service file has changed
sudo systemctl daemon-reload
# restart the service
sudo systemctl restart demo
# start of VM restart
sudo systemctl enable demo

Step 6: Create GitHub action

• Create .github/workflows folder in your source code

mkdir -p .github/workflows

• Create .github/workflows/main.yml to run action

touch .github/workflows/main.yml

• Add workflow to ssh into vm and run the deloy.sh script with correct release tag

Note: add ~/.ssh/google_compute_engine Private key in your github repository secret. Also add IP address as secret so that you don't expose it unnecessarily. Also change SSH_USERNAME as per your VM

name: GitHub Actions Demo
on:
  release:
    types: [published]
jobs:
  Explore-GitHub-Actions:
    runs-on: ubuntu-latest
    steps:
      - name: Get the version
        id: get_version
        run: echo ::set-output name=VERSION::${GITHUB_REF/refs\\/tags\\//}
      - name: Debug version
        id: Debug
        run: echo ${{ steps.get_version.outputs.VERSION }}
      - name: executing remote ssh commands using ssh key
        uses: appleboy/ssh-action@master
        with:
          host: ${{ secrets.GCP_IP }}
          username: SSH_USERNAME
          key: ${{ secrets.GCP_PRIVATE_KEY }}
          port: 22
          script: /bin/sh deploy.sh ${{ steps.get_version.outputs.VERSION }}