🚀 Mastering Azure Functions in Docker: Secure Your App with Function Keys! 🔒

In this session, we’re merging the robust capabilities of Azure Functions with the versatility of Docker containers.

By the end of this tutorial, you will have a secure and scalable process for deploying your Azure Functions within Docker, equipped with function keys to ensure security.

Serverless architecture allows you to run code without provisioning or managing servers. Azure Functions take this concept further by providing a fully managed compute platform. Docker, on the other hand, offers a consistent development environment, making it easy to deploy your applications across various environments. Together, they create a robust and efficient way to develop and deploy serverless applications. Later we will be deploy this container to our local kubernetes cluster and to Azure Container Apps.

The Azure Functions Core tools make it easy to package your function into a container with a single command:

func init MyFunctionApp --docker

The command creates the dockerfile and supporting json for your function inside a container and all you need to do is add your code and dependencies. Since we are building a python function we will be adding our python libraries in the requirements.txt

Create a host_secret.json file in the root of your function app directory. Add the following configuration to specify your function key:

{
"masterKey": {
"name": "master",
"value": "your-master-key-here"
},
"functionKeys": {
"default": "your-function-key-here"
}
}

Now this file needs to be added to the container so the function can read it. You can simply add the following to your dockerfile and rebuild:

RUN mkdir /etc/secrets/
ENV FUNCTIONS_SECRETS_PATH=/etc/secrets
ENV AzureWebJobsSecretStorageType=Files
ENV PYTHONHTTPSVERIFY=0
ADD host_secrets.json /etc/secrets/host.json

Now you can use the function key you set in the previous step as a query parameter for the function’s endpoint in your api client.

Or you can use curl / powershell as well:

curl -X POST \
'http://192.168.1.200:8081/api/getbooks?code=XXXX000something0000XXXX' \
--header 'Accept: */*' \
--header 'User-Agent: Thunder Client (https://www.thunderclient.com)' \
--header 'Content-Type: application/json' \
--data-raw '{
"query": "Dune"
}'