I've followed this blog trying to deploy my Angular app to Azure App Service. It seems to work, the build takes place and the rollout happens as supposed to (as far i can tell). However on the start, I get "Application Error" and the following log appears in the console.
2024-04-10T19:52:27.081Z INFO - Starting container for site
2024-04-10T19:52:27.083Z INFO - docker run -d --expose=8080 --name app-puf-gui-dev_0_910ed413 -e WEBSITE_USE_DIAGNOSTIC_SERVER=true -e WEBSITE_SITE_NAME=app-puf-gui-dev -e WEBSITE_AUTH_ENABLED=False -e WEBSITE_ROLE_INSTANCE_ID=0 -e WEBSITE_HOSTNAME=app-puf-gui-dev.azurewebsites.net -e WEBSITE_INSTANCE_ID=94e1cb8215dce9f31465132c8957e6ec3ef6a14c876f2c4d8780bfb99d805518 appsvc/node:20-lts_20240207.3.tuxprod pm2 serve /home/site/wwwroot -no-daemon-spa
2024-04-10T19:52:27.084Z INFO - Logging is not enabled for this container.Please use https://aka.ms/linux-diagnostics to enable logging to see container logs here.
2024-04-10T19:52:28.525Z INFO - Initiating warmup request to container app-puf-gui-dev_0_910ed413 for site app-puf-gui-dev
2024-04-10T19:52:34.770Z ERROR - Container app-puf-gui-dev_0_910ed413 for site app-puf-gui-dev has exited, failing site start
2024-04-10T19:52:34.786Z ERROR - Container app-puf-gui-dev_0_910ed413 didn't respond to HTTP pings on port: 8080, failing site start. See container logs for debugging.
2024-04-10T19:52:34.799Z INFO - Stopping site app-puf-gui-dev because it failed during startup.
The build pipeline follows (roughly) this setup, except I only target a single environment. I've been googling, reading and trying to get some traction but I realize that I'm stuck not being able to diagnose it further. As far I can confirm, the issue is with the hosting that serves the application. But how/why - I have zero clue.
I have narrowed it down to those two lines. At the first one, it's still all good, at the next one, we're done.
How do I troubleshoot it more?
I've found the reason in my particular case to be a typo on the execution path in Azure. The (almost perfect) source is this great article, with the only flow that the mentioned flag got distorted in rendition saying pm2 serve /home/site/wwwroot -no-daemon-spa.
It should be:
pm2 serve /home/site/wwwroot --no-daemon --spa