Azure-docs: My app would not function until I added a route for robots933456.txt

[carlpoole]

Hello! My custom container kept failing to start correctly. I was able to find the logs and I saw my app logs showing that it had started correctly and was listening on port 80, but then it was quickly followed by a time out after 250 seconds or so and cease to function.

It contained a Node JS app made with express. When I reviewed the logs I noticed that my app would receive many requests for "robots933456.txt", which my app did not handle. I had to search this back through Google to find a previous issue where someone had complained this was not documented anywhere as being a necessary route for a health-check. I noticed this was specifically referencing PHP in particular and it was documented in that section, but my app is a custom container running a Node JS Express app.

I think the documentation for this requirement is important and still hard to see without deep digging and hours of debugging.

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Document Details

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• ID: f970943e-c7b4-919c-65ea-6ba20831e74d
• Version Independent ID: 90c5dd06-ea6d-7af8-f88c-9d189e9ceef2
• Content: Build a custom image and for Web App for Containers - Azure App Service
• Content Source: articles/app-service/containers/tutorial-custom-docker-image.md
• Service: app-service
• GitHub Login: @msangapu
• Microsoft Alias: msangapu

[BryanTrach-MSFT]

@carlpoole Thanks for the feedback! We are currently investigating and will update you shortly.

[DashleenBhandari-MSFT]

@carlpoole , So in order to ensure a container is up and running and ready to serve requests our Platform has to ensure that the web server inside the container is capable of handling requests. While the app container is starting up, our platform keeps sending HTTP requests to /robots933456.txt inside the container. Now /robots933456.txt doesn't actually exist inside a container but the intention for which this is done is to get a non-5xx response from the webserver inside the container. Which implies the web server is ready to handle requests. Even a 404 response is a valid response since it confirms to the Platform that the web server inside the container is up and sent the 404.

[carlpoole]

Thanks for the info. Our app wasn't setup with this in mind but I have configured it to send 404 messages now.

[DashleenBhandari-MSFT]

@carlpoole , Thanks for the response. I will go ahead and close the issue. If you need any other assistance please feel free to re-open the same

[xtianus79]

@DashleenBhandari-MSFT and @BryanTrach-MSFT so how do you actually do this?

[xtianus79]

I figured out how to do this and this information should be added in documentation because it would prevent someone from running any angular app until this is implemented.