Comparison of Two Methods for Deploying Azure Functions to Azure Container Apps

Yesterday, I wrote an article titled “Deploying a Java Azure Function on Azure Container Apps.”

In that entry, I mentioned using the Azure's integrated management capabilities and I want to clarify what that means and how it differs from previous methods in this article.

Old Method: Creating with az containerapp create

Azure Container Apps is one of Azure’s container execution environments, allowing you to run any containerized service. Previously, if you wanted to run Azure Functions in Azure Container Apps, you would create an instance using the following command:

az containerapp create \
--name general-container-app \
--resource-group $RESOURCE_GROUP_NAME \
--environment $CONTAINER_ENVIRONMENT \
--registry-server $CONTAINER_REGISTRY_SERVER \
--image $CONTAINER_REGISTRY_SERVER/$C_IMAGE_NAME:$C_IMAGE_TAG \
--target-port 80 \
--ingress external \
--query properties.configuration.ingress.fqdn

After executing the command, you would see a message like this:

Container app created. Access your app at https://general-container-app.niceocean-********.eastus.azurecontainerapps.io/

You could then use a curl command to connect to your Azure Functions service:

curl https://general-container-app.niceocean-********.eastus.azurecontainerapps.io/api/httpexample?name=World

Upon accessing the Azure Container Apps Environment, you would see that the general-container-app is created as a Container App, and this management interface is available for any deployed containerized application.

https://raw.githubusercontent.com/yoshioterada/Azure-Functions-Deploy-To-Azure-Container-Apps/main/images/ACA-Instance-for-Azure-Functions.png

New Method: Creating with az functionapp create

The new method allows you to create Azure Functions in Azure Container Apps using the az functionapp create command instead of az containerapp create.

az functionapp create \
--name $AZURE_FUNCTION_NAME \
--resource-group $RESOURCE_GROUP_NAME \
--environment $CONTAINER_ENVIRONMENT \
--storage-account $STORAGE_NAME \
--workload-profile-name "Consumption" \
--max-replicas 15 \
--min-replicas 1 \
--functions-version 4 \
--runtime java \
--image $CONTAINER_REGISTRY_SERVER/$C_IMAGE_NAME:$C_IMAGE_TAG \
--assign-identity

With this command, your Azure Functions will be created in Azure Container Apps, and the management interface will clearly show that it is an Function App.

This means Azure Functions can now be managed through a dedicated Azure Functions management interface, making it difference from other container application.

However, there are some differences between the management features provided in Azure App Service and those available for Azure Functions on Container Apps. For instance, certain functionalities like diagnostic tools, deployment features, and others may not be available.

Reference: Azure Functions on App Service (Portal)

For comparison, here’s the management interface for Azure Functions deployed on Azure App Service.

The differences in management capabilities between App Service and Azure Container Apps can include:

- Diagnose and solve problems
- Microsoft Defender for Cloud
- Events (preview)
- Log stream
- Deployment
- App Service plan
- Development Tools
- Monitoring
- Support + troubleshooting

Some may think that the lack of certain features suggests missing functionality.

However, when deployed to Azure Container Apps, the operating environment is container-based, which changes deployment and management methods. Features not included in the Azure Functions management interface will need to be managed separately through the Azure Container Apps interface.

Management of Containers in Azure Container Apps

When using the az functionapp create command to create an Azure Functions instance on Azure Container Apps, a new resource group is automatically created that houses the container instance.

In my environment, the resource group name follows this convention:

$CONTAINER_ENVIRONMENT_FunctionApps_$UUID

You will see that an Azure Container Apps instance named after your specified $AZURE_FUNCTION_NAME has been generated.

When you click on this instance, you’ll be directed to a management interface specific to Azure Container Apps, where the Azure Functions run as container instances.

Azure Container Apps provides different CI/CD and deployment methods than Azure App Service. It also allows for features offered at the container level, such as Dapr and Service Connector, which can be utilized.

Conclusion

Previously, it was possible to run Azure Functions by containerizing them in a container execution environment, but there was no dedicated management interface for Azure Functions.

With this new method, Azure Functions and Azure Container Apps have integrated, offering a container environment with an associated Azure Functions management interface.

I know some customers operate Azure Functions Container on Azure Kubernetes Service (AKS). Previously, they lacked a dedicated management interface. However, by deploying to Azure Container Apps, they can now use Azure Functions management while enjoying the simplicity of managing Azure Container Apps compared to managing operations on AKS.

The methods for deploying Azure Functions to Azure Container Apps are likely to evolve further. I look forward to seeing how this develops.