Deploy Node App

DeployNodeApp.yaml

name: CD

# Controls when the action will run. 
on:
  # Triggers the workflow on push or pull request events but only for the master branch
  push:
    branches: [ master ]
  # Allows you to run this workflow manually from the Actions tab
  workflow_dispatch:

# A workflow run is made up of one or more jobs that can run sequentially or in parallel
jobs:
  # This workflow contains a single job called "build"
  build:
    # The type of runner that the job will run on
    runs-on: ubuntu-latest

    # Steps represent a sequence of tasks that will be executed as part of the job
    steps:
      # Checks-out your repository under $GITHUB_WORKSPACE, so your job can access it
      - uses: actions/checkout@v2
      
      - name: SSH
        uses: appleboy/ssh-action@v0.1.4
        with:
          # ssh host
          host: <your server url>
          # ssh port
          port: <your ssh port if changed>
          username: <your username>
          # ssh key passphrase
          key: ${{ secrets.SSH_SECRET_KEY}}
          script: | 
           cd reponame/
           pm2 stop appname
           git fetch --all
           git reset --hard origin/master
           git pull
           npm install
           cd client/
           npm install 
           cd ../
           npm run build
           rm -rf src/
           pm2 start ecosystem.config.yaml

pm2 stop only works if you do not change the pm2 file itself. Otherwise you would need to delete it. This is a multi repo project.
The git pull part is a bit ugly. You might get away with building it beforehand and not on the server.