How to set up NodeJS backend on Azure App Service, server.ts is not reachable

Question

How to set up NodeJS backend on Azure App Service, server.ts is not reachable

John Siri 0

Short: My application's nodeJS backend is not running in Azure App Service.

The app does successfully build, go through the workflow, and launches the frontend.

After the backend of my application is deployed, no script is able to start the server.ts file that runs the whole thing. I initially thought it was related to the startup commands, but no iteration of the available commands worked. On top of that, I reconfigured ports to work with port 443, as opposed to the 3000 that it previously ran. A js version also does not work well.

In the SSH terminal, I noticed that some of the npm commands did not work and the server.ts file was not able to be interpreted (as typescript). It also was not being built into dist. My frontend works fine, but there is no successful ping from the backend to the frontend. Trying to directly go to the url takes me immediately to the frontend. I am not getting a 503 error.

My current config scripts are as follows:

"scripts": {
   "dev": "vite",
   "build": "tsc -b &&  vite build --base=./",
   "lint": "eslint .",
   "preview": "vite preview",
   "serverStart": "nodemon src/server.ts",
   "server": "node src/server.ts",
   "start": "tsx /src/server.ts",
   "docker-acs": "docker-compose up",
   "acs": "cd azure-communication-server && tsx azure-communication-server.tsx"
},

I am primarily using serverStart.

Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-14T10:50:37.5866667+00:00
Hi John Siri,
Your server.ts file is not turning into JavaScript (dist/server.js or similarly), which is necessary since the Azure App service, which cannot run the typescript files directly.

A clear startup command is required, pointing to the Azure app service to the JavaScript file -made JavaScript file - not the typescript source, only becomes a frontend, so the backend code (server.ts) is never converted or launched.

Azure hopes to hear your app on port defined by port environment variable (443 or 3000 hardcoded).
1.Ensure that your startup command is correctly configured to run your application. If you are using a typescript, you have to compile it to JavaScript before walking. You can set the Startup Command to run the JavaScript file compiled directly instead of the typescript file. For example:

npm run build && node dist/server.js

You can add this in the App Service > Configuration > General Settings > Startup Command in the Azure Portal.

Azure App Service usually uses port 80 or 443 for http and https traffic. Make sure your application is set to listen at the correct port. You can use the environment variable port to dynamically set the port in your application:

const PORT = process.env.PORT || 3000; app.listen(PORT, () => { console.log(`Server is running on port ${PORT}`); });

3.Use log stream feature in Azure App Service to check any error during startups. It can help identify whether there are problems with your application or if it is failing to start.

4.Make sure that your perfection method is correctly configured. If you are using zip -purpose or git, make sure that the package.JSON file is set correctly with the required script.

If the problems persist, consider enabling remote debugging in the visual studio code to prevent the application directly on the azure.

Ensure that your typescript files are being compiled into JavaScript and the output is being placed in the distinguished. You can check your build configuration in your tsconfig.json.

https://learn.microsoft.com/en-us/azure/app-service/configure-language-nodejs?pivots=platform-linux#troubleshooting
https://learn.microsoft.com/en-us/azure/app-service/configure-language-nodejs?pivots=platform-linux#configure-nodejs-server
if you have any further concerns or queries, please feel free to reach out to us.
Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-15T08:57:57.9+00:00

Hi John Siri,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
John Siri 0 Reputation points

2025-04-15T15:48:08.1433333+00:00

Hello,

I haven't been able to bundle the server into the dist folder. Is there a way to specify it as an additional file to include?
Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-16T09:59:32.9+00:00
Hi John Siri,
Can you Check the server.ts Gets Compiled to dist/
Use type script complier
Ensure server.ts is inside src/ folder (or your rootDir)
Update tsconfig.json to include the backend:

{ "compilerOptions": { "outDir": "./dist", "rootDir": "./src", ... }, "include": ["src/**/*"] // Make sure server.ts is included }

also update your script in json:

"scripts": { "build": "tsc && vite build", "start": "node dist/server.js" }

This will replace or place your compiled Json file with dist/ with your frontend build
Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-17T08:50:27.5866667+00:00

Hi John Siri,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
John Siri 0 Reputation points

2025-04-17T20:12:15.6966667+00:00

Hello, I managed to get the server running on an independent instance. However, I am having some issues sharing Azure Redis sessions between servers on different URLS.Is there a way to ensure that session data is preserved between the standard node server and the azure communication server?
John Siri 0 Reputation points

2025-04-18T05:37:40.1266667+00:00

When trying to set up the Redis cache, it does not transfer sessions between my standard backend server url and communication server url. Should I be trying to marry the sessions, or would it be better to send gets with the necessary information from one to the other and have them run separate sessions.
Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-18T08:57:07.73+00:00

Hello @John Siri , can you check private message and replay there. Than you

Sampath 3,750 Microsoft External Staff Moderator

Hello @John Siri , can you try this example with ts in vite https://github.com/Sampath280/ravi233/tree/main

 "scripts": {
    "dev": "node server",
    "build": "npm run build:client && npm run build:server",
    "build:client": "vite build --outDir dist/client",
    "build:server": "vite build --ssr src/entry-server.ts --outDir dist/server",
    "preview": "cross-env NODE_ENV=production node server",
    "check": "vue-tsc"
  },

vite.config.ts:

import { defineConfig } from 'vite'
import vue from '@vitejs/plugin-vue'
// https://vite.dev/config/
export default defineConfig({
  plugins: [vue()],
  server: {
    allowedHosts: ['sampath.azurewebsites.net'],
  },
})

**
Below the yawl follow:**


name: Build and deploy Node.js app to Azure Web App - sam
on:
  push:
    branches:
      - main
  workflow_dispatch:
jobs:
  build:
    runs-on: ubuntu-latest
    permissions:
      contents: read # Required for actions/checkout
    steps:
      - uses: actions/checkout@v4
      - name: Set up Node.js version
        uses: actions/setup-node@v3
        with:
          node-version: '18.x'
      - name: Install dependencies
        run: |
          npm install
          npm install -g vite
      - name: Build and test
        run: |
          vite build --outDir dist/client
          npm run build:server
          npm run test --if-present
      - name: Zip artifact for deployment
        run: zip release.zip ./* -r
      - name: Upload artifact for deployment job
        uses: actions/upload-artifact@v4
        with:
          name: node-app
          path: release.zip
  deploy:
    runs-on: ubuntu-latest
    needs: build
    environment:
      name: 'Production'
      url: ${{ steps.deploy-to-webapp.outputs.webapp-url }}
    steps:
      - name: Download artifact from build job
        uses: actions/download-artifact@v4
        with:
          name: node-app
      - name: Unzip artifact for deployment
        run: unzip release.zip
      - name: Deploy to Azure Web App
        id: deploy-to-webapp
        uses: azure/webapps-deploy@v3
        with:
          app-name: 'sampujari'
          slot-name: 'Production'
          package: .
          publish-profile: ${{ secrets.AZUREAPPSERVICE_PUBLISHPROFILE_ }}

If you have any further questions, please click Comment

Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-22T11:09:49.32+00:00
Hello @John Siri ,

Sharing Azure Redis sessions between servers on different URLs is possible, but it requires careful configuration to ensure session data is preserved and accessible across multiple servers. Here are some steps and considerations:

Ensure that both servers (standard Node server and Azure Communication server) are connected to the same Redis instance. This allows them to access the same session data.

Use a Redis session store library, such as connect-redis for Node.js, to manage sessions.

If the servers are on different domains, configure cookies to be accessible across domains:

Set the cookie.domain property to a common domain shared by both servers (e.g., .example.com).

Ensure that both servers use the same session secret. Redis sessions have a default expiration time. Ensure that both servers respect the same expiration settings to avoid inconsistencies.

Use HTTPS for both servers to secure session data during transmission.

Enable Redis SSL/TLS if supported by your Redis instance.

For more details, you can explore this guide on maintaining session state across different domains with Azure Redis Cache.

If you have any further questions, please click Comment
Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-23T11:59:29.08+00:00

Hello @John Siri , We still have not heard back from you. If you have any further questions, please click Comment. if helped please let know in the comments
Grmacjon-MSFT 19,151 Reputation points Moderator

2025-04-28T21:59:40.99+00:00
@John Siri adding to Sampath's comment- If your servers are on different subdomains of the same root domain (e.g., backend.website.com and acs.website.com), configure your session cookies as follows:

Set the cookie.domain property to the root domain (e.g., .website.com).

Confirm the cookie.path is set to /.

Use the same cookie.name across both applications.

Please note that if your servers are on completely different domains (e.g., backend.website.com and communication.anotherdomain.com), direct cookie-based session sharing using **cookie.domain **will NOT work due to browser security (Same-Origin Policy).

Also make sure both your standard Node.js server and your azure-communication-server are correctly configured to connect to the same Azure Redis Cache instance using the correct connection string and credentials.

Your answer

Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-15T08:57:57.9+00:00

Hi John Siri,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
John Siri 0 Reputation points

2025-04-15T15:48:08.1433333+00:00

Hello,

I haven't been able to bundle the server into the dist folder. Is there a way to specify it as an additional file to include?
Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-16T09:59:32.9+00:00

Hi John Siri,
Can you Check the server.ts Gets Compiled to dist/
Use type script complier
Ensure server.ts is inside src/ folder (or your rootDir)
Update tsconfig.json to include the backend:

{ "compilerOptions": { "outDir": "./dist", "rootDir": "./src", ... }, "include": ["src/**/*"] // Make sure server.ts is included }

also update your script in json:

"scripts": { "build": "tsc && vite build", "start": "node dist/server.js" }

This will replace or place your compiled Json file with dist/ with your frontend build
Alekhya Vaddepally 1,670 Reputation points Microsoft External Staff Moderator

2025-04-17T08:50:27.5866667+00:00

Hi John Siri,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.
John Siri 0 Reputation points

2025-04-17T20:12:15.6966667+00:00

Hello, I managed to get the server running on an independent instance. However, I am having some issues sharing Azure Redis sessions between servers on different URLS.Is there a way to ensure that session data is preserved between the standard node server and the azure communication server?
John Siri 0 Reputation points

2025-04-18T05:37:40.1266667+00:00

When trying to set up the Redis cache, it does not transfer sessions between my standard backend server url and communication server url. Should I be trying to marry the sessions, or would it be better to send gets with the necessary information from one to the other and have them run separate sessions.
Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-18T08:57:07.73+00:00

Hello @John Siri , can you check private message and replay there. Than you
Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-22T11:09:49.32+00:00

Hello @John Siri ,

Sharing Azure Redis sessions between servers on different URLs is possible, but it requires careful configuration to ensure session data is preserved and accessible across multiple servers. Here are some steps and considerations:

Ensure that both servers (standard Node server and Azure Communication server) are connected to the same Redis instance. This allows them to access the same session data.

Use a Redis session store library, such as connect-redis for Node.js, to manage sessions.

If the servers are on different domains, configure cookies to be accessible across domains:

Set the cookie.domain property to a common domain shared by both servers (e.g., .example.com).

Ensure that both servers use the same session secret. Redis sessions have a default expiration time. Ensure that both servers respect the same expiration settings to avoid inconsistencies.

Use HTTPS for both servers to secure session data during transmission.

Enable Redis SSL/TLS if supported by your Redis instance.

For more details, you can explore this guide on maintaining session state across different domains with Azure Redis Cache.

If you have any further questions, please click Comment
Sampath 3,750 Reputation points Microsoft External Staff Moderator

2025-04-23T11:59:29.08+00:00

Hello @John Siri , We still have not heard back from you. If you have any further questions, please click Comment. if helped please let know in the comments
Grmacjon-MSFT 19,151 Reputation points Moderator

2025-04-28T21:59:40.99+00:00

@John Siri adding to Sampath's comment- If your servers are on different subdomains of the same root domain (e.g., backend.website.com and acs.website.com), configure your session cookies as follows:

Set the cookie.domain property to the root domain (e.g., .website.com).

Confirm the cookie.path is set to /.

Use the same cookie.name across both applications.

Please note that if your servers are on completely different domains (e.g., backend.website.com and communication.anotherdomain.com), direct cookie-based session sharing using **cookie.domain **will NOT work due to browser security (Same-Origin Policy).

Also make sure both your standard Node.js server and your azure-communication-server are correctly configured to connect to the same Azure Redis Cache instance using the correct connection string and credentials.

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How to set up NodeJS backend on Azure App Service, server.ts is not reachable

Your answer