How to Publish an Azure Function - In-Process vs Isolated Models

 Serverless computing is transforming how modern applications are built. One of the most popular serverless offerings is Azure Functions, which allows developers to build event-driven apps without worrying about infrastructure management.

If you’re using Visual Studio, deploying Azure Functions to the cloud can be done in just a few steps. In this guide, we’ll walk through publishing an Azure Function using both the In-Process and Isolated hosting models.

☁️ Step 1: Create a New Azure Function Project

1. Open Visual Studio.
2. Go to File → New → Project.
3. Search for “Azure Functions” and select Azure Functions template.
4. Click Next, name your project, and select the desired location.
5. In the Create a new Azure Functions Application dialog:
1. Choose the trigger type (e.g., HTTP Trigger).
2. Select .NET version.
3. Choose Hosting model:
1. ✅ In-Process (runs inside the same process as the Functions runtime)
2. 🧭 Isolated (runs in a separate process, more flexibility)
6. Click Create.

🧪 Step 2: Understand the Difference Between In-Process and Isolated Models

✅ Recommendation:

• Use In-Process if you want fast startup and have simpler needs.
• Use Isolated if you want full control, better decoupling, and support for the latest .NET features.

🧰 Step 3: Build and Test Locally

Before deploying, it’s always best to test your function locally:

1. Press F5 to run the project.
2. The terminal will show the local endpoint (e.g., http://localhost:7071/api/Function1).
3. Open the URL in the browser or use Postman to test the function.
4. Once you confirm it works, you’re ready to publish.

🌐 Step 4: Publish the Azure Function to the Cloud

1. Right-click the project in Solution Explorer.
2. Click Publish.
3. Choose:
1. Azure → Azure Function App (Windows/Linux) → Next.
4. Select Create a new Azure Function App (or choose an existing one).
5. Fill in:
1. Subscription
2. Resource Group
3. Hosting Plan (Consumption is recommended for cost efficiency)
4. Storage Account
6. Click Finish, then Publish.

Visual Studio will:

• Build the project
• Package the function
• Deploy it to the selected Azure Function App

🔐 Step 5: Verify Deployment

1. Once deployed, the Publish tab will show the Function URL.
2. Open the URL in the browser.
3. You should see the expected output (e.g., “Hello from Azure Function!”).
4. You can also go to Azure Portal, navigate to your Function App, and verify logs in the Monitor section.

⚡ Bonus Tip: CI/CD Integration

For production environments, instead of manually publishing, integrate deployment with:

• GitHub Actions
• Azure DevOps pipelines

This ensures your Azure Functions are automatically deployed on each code push.

🧭 Common Troubleshooting

🏁 Conclusion

Deploying an Azure Function from Visual Studio is fast and efficient.

• The In-Process model works well for most lightweight apps.
• The Isolated model gives you more flexibility and is the future direction for advanced workloads.

By understanding both models and using Visual Studio’s built-in publishing tools, you can get your function live in minutes.