How to fix "Error: Cannot find module '/home/site/wwwroot/index.js" with an app deployed to Azure? – Ubuntu

I’m attempting for the first time to deploy a node.js app to Azure as an Azure App Service, but I’m facing this stubborn error when trying to run the app that I haven’t figured out how to troubleshoot. Maybe someone here has some hints on where I’m making the mistake.

To give some background:

• I’m working on a project that has a subset of directories, each of the directories being an app (server, client, …)
• The main directory is the git directory
• The nodejs app I am working on is built with typescript, and leveraging Apollo Server (which itself leverages express)
• I’m deploying to Azure via GitHub

With that in mind, my project folder structure looks like:

| main_folder
  | .github
    | workflows
        workflow.yml
  | server
    | src
    | dist
    .env
    index.ts
    package-lock.json
    package.json
    tsconfig.json    
  | other_apps
  .gitignore
  README.md

In index.ts I have the code relevant to running the app. The rest of the relevant files look like this:
tsconfig.json

{
    "compilerOptions": {
        "target": "ES2022",
        "module": "CommonJS",
        "lib": [
            "ES2022", "DOM"
        ],
        "strict": true,
        "rootDir": ".",
        "outDir": "./dist",
        "sourceMap": true,
        "esModuleInterop": true
    }
}

package.json

{
  "name": "server",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "dev": "ts-node-dev --transpile-only --no-notify --exit-child index.ts",
    "build": "npx tsc",
    "start": "node ."
  },
  // ...
}

workflow.yml

on:
  push:
    branches: ["master"]
  workflow_dispatch:

env:
  AZURE_WEBAPP_NAME: my-app-name 
  AZURE_WEBAPP_PACKAGE_PATH: "." # set this to the path to your web app project, defaults to the repository root
  NODE_VERSION: "16.x" # set this to the node version to use

permissions:
  contents: read

jobs:
  build:
    runs-on: ubuntu-latest
    defaults:
      run:
        working-directory: ./server
    steps:
      - uses: actions/checkout@v3

      - name: Set up Node.js
        uses: actions/setup-node@v3
        with:
          node-version: ${{ env.NODE_VERSION }}
          cache: "npm"
          cache-dependency-path: ./server/package-lock.json

      - name: npm install, build, and test
        run: |
          npm install
          npm run build --if-present
          npm run test --if-present

      - name: Zip artifact for deployment
        run: zip -r release.zip ./* .env

      - name: Upload artifact for deployment job
        uses: actions/upload-artifact@v3
        with:
          name: node-app
          path: ./server/release.zip

  deploy:
    permissions:
      contents: none
    runs-on: ubuntu-latest
    needs: build
    environment:
      name: "Development"
      url: ${{ steps.deploy-to-webapp.outputs.webapp-url }}

    steps:
      - name: Download artifact from build job
        uses: actions/download-artifact@v3
        with:
          name: node-app

      - name: unzip artifact for deployment
        run: unzip release.zip

      - name: "Deploy to Azure WebApp"
        id: my_app_id
        uses: azure/webapps-deploy@v2
        with:
          app-name: ${{ env.AZURE_WEBAPP_NAME }}
          publish-profile: ${{ secrets.AZURE_WEBAPP_PUBLISH_PROFILE }}
          package: ${{ env.AZURE_WEBAPP_PACKAGE_PATH }}

This app works perfectly fine in local (running npm run dev). When I push to master in GitHub, both the build & deployment jobs work correctly. However, when I go to Azure Portal and check on the app, I see these two things:

When I open the url for the app, the page shows:

When I check the diagnostics of the app in Azure, it tells me:

The error being Error: Cannot find module '/home/site/wwwroot/index.js'. While setting up the configurations for automatic build & deployment in GitHub I faced several issues with my project structure, as my git repository doesn’t actually contain any app (package.json), but they are instead in nested folders. However, I don’t think this error stems from that set up, but from somewhere else.

Can somebody hint me on what I’m doing wrong here? I’ll repeat that this is my first attempt at publishing a nodejs app to Azure, and even though I think I followed the docs correctly, there are chances I messed up in an obvious step. I would appreciate having anybody pointing it out if that’s the case!

I’ll be happy to add any more information to the description that might be relevant to the issue.