How to deploy Docker Hub Linux image to Azure Function? Portal for Function already shows my Docker Image!

Question

I have used visual studio to deploy my compiled C# azure function to dockerhub. I did not see any errors in the visual studio output. I logged into docker hub to confirm that it has been pushed: Yes there is a new image there. Then I use a bash prompt:

az functionapp create  --name $FUNC --resource-group  $rg   --storage-account $funcstg --os-type Linux  --image $DOCKERHUB_USERNAME/$DOCKER_IMAGE:v1  --registry-username $DOCKERHUB_USERNAME --registry-password $DOCKERHUB_PASSWORD --resource-group $rg --runtime dotnet --functions-version 4 --consumption-plan-location $loc

I got this in response:

WARNING: Your Linux function app 'funcCrewTaskMgrAuthenticatedServices', that uses a consumption plan has been successfully created but is not active until content is published using Azure Portal or the Functions Core Tools.

WARNING: Application Insights "funcCrewTaskMgrAuthenticatedServices" was created for this Function App. You can visit https://portal.azure.com/#resource/subscriptions/accxxxxxxxxxxxxxxxxxxxxxxxxxdb/resourceGroups/rg_xxxxxxxxx/providers/microsoft.insights/components/funcCrewTaskMgrAuthenticatedServices/overview to view your Application Insights component

I go to my dockerhub account and confirm that the new docker image has been pulled.

I go to the portal.azure.com and go to my azure function app and click on "deployments" and there I see my dockerhub username & password and image name. Looks good!

But then I click on Functions and I see no functions!

1. Why don't I see any functions?
2. How do I use the portal to populate my functions?
3. How do I use azure core tools for this final step? I looked at the documentation and I could not figure out the this final step. The azure core tools tutorial just recommends az functionapp create...like I had already done.
4. How do I use the azure cli to populate my functions?

Thanks

Siegfried

I found this https://learn.microsoft.com/en-us/answers/questions/1192379/how-to-create-a-functionapp-from-docker-image-in-a it looks like I have already done that that answer recommends.

Answer 1

Hey @Siegfried Heintze ,

You created your function app using the wrong command. Docker images for Function apps aren't supported on Consumption plans. You need create a function app on a premium or dedicated app service plan, az functionapp plan create --resource-group AzureFunctionsContainers-rg --name myPremiumPlan --location <REGION> --number-of-workers 1 --sku EP1 --is-linux.

See Create a function on Linux using a custom container for more details.

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EDIT 30 May 2023

From a CLI standpoint, you're not missing anything. I verified this on EP1 as well as B1 Linux plans (az appservice plan create --name plan --sku B1 --is-linux). I basically did the following:

az functionapp plan create --name plan-ryhill-linux-westus2 --sku EP1 --is-linux true
az functionapp create --functions-version 4 --name ryhilldockerapponpremium  --os-type linux --runtime dotnet-isolated --storage-account stryhillacct --image xxxregistry.azurecr.io/api:20230530005907 --https-only true --plan plan-ryhill-linux-westus2

to deploy this Dockerfile. The function doesn't show up automatically until the docker image is completely loaded and ready to take requests.

Since you're not seeing your function, I would look your deployment logs for any errors and that your container is serving requests.

Answer 2

Thank you again Ryan!

I wish they would give me more helpful error messages!

Problems solved:

1. For some strange reason, it is necessary for me to log into my own dockerhub repo to fetch a public image.
2. I had the tag wrong.

I'm very glad to learn that I don't need a premium azure function for linux! I must have misunderstood the azure pricing calculator. I had to learn the hard way that even if you delete the function app for a premium function, you are still charged until you delete the premium plan! (Fortunately, I begged for mercy and they are going to refund my those charges).