Use Connection Strings from Function App configuration in Docker Image for Deployment on AKS (using KEDA)

Anchitaa Gupta 1

We have our functions written in DOTNET running on Function App. We need to containerize the same and deploy on Kubernetes (AKS). The problem is with passing environment values to it in AKS. We can pass the Application Settings in Function App under Configuration as secrets in AKS but I am not abele to figure out a way to pass Connection Strings being used as parameters to the image we deploy in AKS.

For a better picture,

How do I use parameters under Connection Strings in Kubernetes? Is there a way to pass these parameters at runtime to the docker image in AKS without having to change the underline code?

Anchitaa Gupta 1 Reputation point

2022-02-11T18:36:39.833+00:00

@Stephen Harper Would you be able to please help us here?

1 answer

AnuragSingh-MSFT 19,686 Reputation points

2022-02-14T11:24:15.483+00:00

Hi @Anchitaa Gupta

Welcome to Microsoft Q&A! Thanks for posting the question.

With AKS, the environment variables are defined in the POD configuration using the env: field. Please refer to Define Environment Variables for a Container for more details.
You may also refer to this article for usage sample and deployment quick start to AKS.

Please let me know if you have any questions.

---
Please 'Accept as answer' and ‘Upvote’ if it helped so that it can help others in the community looking for help on similar topics.
Please sign in to rate this answer.

1 person found this answer helpful.
Anchitaa Gupta 1 Reputation point

2022-02-15T17:31:05.153+00:00

Hi @AnuragSingh-MSFT thank you for answering the question.

I am specifically looking for a way to reuse parameters under connection strings that we create in function app to be reused in Kubernetes deployment using KEDA. While I am able to use application settings parameters (below screenshot attached) as environment variables (secrets) in K8s, the connection strings parameters are not being picked up by function deployed in AKS.

Here is my Dockerfile-

I need to use parameters under connection strings in Function App configuration, when we containerize the same function and run in AKS. Tried mounting these as environment vars as secrets, but the values are not being picked up by function when deployed in AKS.

Please let me know if any details are required.

AnuragSingh-MSFT 19,686 Reputation points

2022-02-17T15:44:39.79+00:00

@Anchitaa Gupta , thank you for the clarification. Kubernetes (in this case Azure K8S) does not have settings as shown in the image above. Those options are available from "Azure Function App" service. For Azure Functions in k8s with KEDA, the deployment happens in k8s cluster, therefore the environmental option available here are the same as available any other type of load in k8s cluster (WebApp, middleware or DB). Here, instead of using the dotnet runtime, for example, the Azure Function runtime will be used that faciliate the development of serverless functions.

The following article contains the complete walkthrough for this scenario, including handing of secrets and connection string in this type of deployment: Scaling Azure Functions from zero to (n) hero on Kubernetes with KEDA

(Part 1)

AnuragSingh-MSFT 19,686 Reputation points

2022-02-17T15:50:40.617+00:00

@Anchitaa Gupta , Please note that, when you use func kubernetes deploy option (ref available here), the created manifest also contains the environment variables imported from your local.settings.json file. You may use the --dry-run option with this command to review the cretaed yaml deployment file. These environment variables are available under data: section of the created yaml file as base64 encoded:

These can be referred in the code as

string conStr = Environment.GetEnvironmentVariable("connstr");

You may refer to the following link for using Azure Key Vault with k8s:
Azure Key Vault Provider for Secrets Store CSI Driver in an AKS cluster:

Please let me know if you have any questions.

(Part 2)

---
Please 'Accept as answer' if it helped so that it can help others in the community looking for help on similar topics.

AnuragSingh-MSFT 19,686 Reputation points

2022-02-23T04:00:31.7+00:00

@Anchitaa Gupta , I wanted to check if you had a chance to review the reply above.
Please let me know if you have any questions.

---
Please 'Accept as answer' and ‘Upvote’ if it helped so that it can help others in the community looking for help on similar topics.

Anchitaa 1 Reputation point

2022-02-27T19:11:56.94+00:00

@AnuragSingh-MSFT thank you for the response, this answers my question

AnuragSingh-MSFT 19,686 Reputation points

2022-02-28T03:23:32.783+00:00

@Anchitaa , Thank you for the update.
Please 'Accept as answer' and ‘Upvote’ it, so that it can help others in the community looking for help on similar topics.
Sign in to comment