Azure Functions dont deploy when I try to import pymssql

Question

I want my azure functions to be able to connect to my azure SQL server/database.

I have configured the connection using SQL username and password and this works as expected when running locally.

However, when I try to deploy my functions to azure, they dont register when I include import pymssql in my script. When I comment this out, they deploy successfully.

I have included pymssql at version 2.2.5 in my requirements.txt and my function app is running on python 3.11

Thanks!

edit- the functions don’t deploy whenever I try any import such as import pandas. These are included in my requirements.txt which is the root of my directory and .yml

Answer 1

Hi ,

Thanks for reaching out to Microsoft Q&A.

The issue you're encountering is likely related to the deployment process of your Azure Functions app. When you include additional Python packages (example: pymssql or pandas), Azure Functions needs to ensure those dependencies are correctly installed and included during the deployment. Here's how you can troubleshoot and resolve the issue:

Steps to Fix the Deployment Issue:

1. Ensure Correct Dependency Management
   • Verify your requirements.txt includes all the dependencies your function needs, such as:

          
          
          pymssql==2.2.5
     

pandas ```

 - Place `requirements.txt` in the root directory of your Azure Function app.
 
 **Check Python Version Compatibility**
 
    - Ensure that the version of Python (3.11) you are using in Azure is compatible with the libraries listed in your `requirements.txt`.
    
       - Note: Some libraries may not yet fully support Python 3.11. You can check library compatibility in their documentation or try using Python 3.9 as a fallback (Python 3.9 is well-supported in Azure Functions).
       

1. Enable Remote Build for Dependencies
   • By default, Azure Functions on Linux uses remote build to install dependencies. Ensure remote build is enabled in your deployment settings. To do so:

          bash
          
          func azure functionapp publish <FUNCTION_APP_NAME> --build remote
     

     • Alternatively, set the --build remote flag when deploying via Azure CLI or in your CI/CD pipeline.
2. Create a .python_packages Folder Locally
   • If you are deploying from your local machine without remote build, ensure dependencies are pre-installed. Run:

          bash
          
          pip install -r requirements.txt --target=.python_packages/lib/site-packages
     

     • Ensure the .python_packages directory is included in your deployment.
     Check Deployment Logs
     • Review deployment logs in the Azure Portal to identify the exact cause of the failure. Logs can be found under Azure Functions App > Monitoring > Log Stream or Deployment Center.
3. Upgrade Azure Functions Core Tools
   • If you're using Azure Functions Core Tools locally for deployment, ensure you're using the latest version:

          bash
          
          npm install -g azure-functions-core-tools@4 --unsafe-perm 
     

     • Older versions may not handle dependency installations correctly.
4. Use App Service Storage for Large Dependencies
   • If your dependencies are large (ex: pandas), you might run into deployment size limits. In this case:

     - Enable **App Service Storage** for your Azure Function app:
     
              - Go to **Azure Portal** > **Function App Settings** > **Configuration** > **General Settings**.
     
                       - Set `WEBSITE_RUN_FROM_PACKAGE` to `1`.
     
                             - Package your dependencies in a zip file and upload it to a storage account. Update the function app to reference this package.
     

5. Switch to Docker for Deployment (Optional)

• If remote builds are still causing issues, consider deploying using a custom Docker container with all dependencies pre-installed. This approach gives you full control over the environment.
  • Create a Dockerfile like this:

         
         
         FROM mcr.microsoft.com/azure-functions/python:4-python3.11
    

COPY . /home/site/wwwroot RUN pip install -r /home/site/wwwroot/requirements.txt ```

• Build and deploy:

       bash
       
       docker build -t <your-container-name> .
  

docker push <your-container-name> ```

1. Test Dependency Compatibility in Azure
   • Verify that your dependencies are compatible with Azure’s runtime environment. Azure Functions may have specific restrictions based on the underlying platform.

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