APM-server docker image does not support curl, preventing proper health test

[Gil_Zigelman]

APM Server version docker image: 8.13.4

The docker image does not support curl command.
I would like to use curl to detect whether apm-server is healthy for dependent services.

Steps to reproduce**:

1. docker run -it elastic/apm-server:8.13.4
   2.docker ps --> look for the id if the apm-server container
   3.docker exec -it [CONTAINER_ID] /bin/bash
2. curl
3. Observe error message: "bash: curl: command not found"

Is there some alternative way to health check the apm-server container?

Thank you!

[axw (Andrew Wilkins)]

A couple of stop-gap options:

• you could manually craft an HTTP request with bash: How to execute healthcheck without curl · Issue #58 · dart-lang/dart-docker · GitHub
• build a derivative image which installs curl

I think it would probably make sense for us to add an apm-server sub command (apm-server test server or something like that...) for performing a healthcheck, and defining that in the Docker image.

[wrobitza_aveq (Werner Robitza)]

Any updates on this? There isn’t even a package manager in the image, so neither apt/microdnf/apk works to install curl from a derived image.

(Note: HEALTHCHECK --start-period=30s --interval=30s CMD bash -c ':> /dev/tcp/127.0.0.1/8200' || exit 1 seems to work but it’s probably not ideal to test the actual health.)