Azure App Service shared hosting breaking container startup

Question

I have an Azure App Service running my own docker image based on node:14-alpine.

Deploying to the service works and the website runs as expected.

I want to be able to share a few files between the containers, I had previously been using an Azure FileStorage account mapped as a docker volume, this worked however for some reason docker/pm2/node would constantly perform writes meaning a massive cost.

I wanted to use the in-built persisted storage and set the application setting WEBSITES_ENABLE_APP_SERVICE_STORAGE to true, in theory this should share the /home directory between containers and enable storage to persist reboots.

However after changing this setting and restarting, the container no longer starts successfully and gives no reason why.

The logs I get are below:

docker run -d -p 2641:3001 --name [service_name]_2_d9625e76 -e PORT=3001 -e WEBSITES_ENABLE_APP_SERVICE_STORAGE=true -e WEBSITE_SITE_NAME=[service_name] -e WEBSITE_AUTH_ENABLED=False -e WEBSITE_ROLE_INSTANCE_ID=0 -e WEBSITE_HOSTNAME=[service_name].azurewebsites.net -e WEBSITE_INSTANCE_ID=962880a44b3c94xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx1e1a66c48ac6b9 -e HTTP_LOGGING_ENABLED=1 [service_name].azurecr.io/[service_name]:latest

2021-04-06T17:47:14.867Z INFO  - Initiating warmup request to container [service_name]_2_d9625e76 for site [service_name]
2021-04-06T17:47:30.612Z INFO  - Waiting for response to warmup request for container [service_name]_2_d9625e76. Elapsed time = 15.7444228 sec
... lots of lines
2021-04-06T17:56:52.574Z INFO  - Waiting for response to warmup request for container [service_name]_2_d9625e76. Elapsed time = 577.707016 sec
2021-04-06T17:57:14.909Z ERROR - Container [service_name]_2_d9625e76 for site [service_name] did not start within expected time limit. Elapsed time = 600.041979 sec
2021-04-06T17:57:14.916Z ERROR - Container [service_name]_2_d9625e76 didn't respond to HTTP pings on port: 3001, failing site start. See container logs for debugging.

I can't find any more logs to check or any reason it would fail.

What is WEBSITES_ENABLE_APP_SERVICE_STORAGE breaking about my container? I have bash access to the running kudu instance but I can't even find the node website modules.

Are there any logs that would allow me to view what is failing or anything I've not considered with the WEBSITES_ENABLE_APP_SERVICE_STORAGE setting?

How do you deploy the image to Azure App Service? The docker-compose file or just in the Azure portal? — Charles Xu
Have you tried adjusting the container wait time to max by setting WEBSITES_CONTAINER_START_TIME_LIMIT = 1800? — Jason Pan
@CharlesXu I use a Dockerfile to build the container, this is pushed to an Azure Container Registry which uses a webhook to trigger a deployment in the App Service — bendataclear
I mean the first deployment, do you create the app service in the Azure portal with a docker-compose file? or use the command? — Charles Xu
@CharlesXu I created the app using the portal but not a docker compose file, I used "Single container" and selected the image from the container registry — bendataclear

Charles Xu Charles Xu · Accepted Answer · 2021-04-08T08:20:32

First of all, enable persistent storage by setting the environment variable WEBSITES_ENABLE_APP_SERVICE_STORAGE as true does not affect the container operation. It only means you can use persistent storage or not.

Second, if you set the environment variable WEBSITES_ENABLE_APP_SERVICE_STORAGE as true, then you also need to configure the mount path. Up to now, as I know it only can be configured in the docker-compose file. Here is the example.

If you only want to deploy it in Azure Portal with a single container. Then I recommend you use the storage account. In this way, you only need to configure the mapping in the settings. Here are the steps.

Azure App Service shared hosting breaking container startup

1 Answers