Finding where a package is installed

Recently, I faced an issue on a CentOS box where I had to find the location of a package. My application was running on it and I wanted to modify its config. I was unable to pick the config in /etc so I figured it must be in the folder in which the application is installed.

The application was installed as a daemon but it seems the PATH was not updated. I searched in the usual locations of binaries and packages but I could not find it. The only option left for me was to find out where it was installed.

Using the following command showed all the files of the application package.

rpm -ql <my application>

From the list, I could see where my config file was placed during install.

Unexpected exit of Elasticsearch container

I was trying the Elasticsearch container image on docker hub. I was disappointed by the complete lack of error message in the following scenario.

I had my setup defined in a compose file. When I tryed to start the container, I got only the following log line.

OpenJDK 64-Bit Server VM warning: Option UseConcMarkSweepGC was deprecated in version 9.0 and will likely be removed in a future release.

As it is a warning, I expected the container to start but it had not started. Digging a bit more, I found that the exit code was 137 which meant the container needed more memory than the docker daemon was configured for. The fix is quite easy of course but I think it could have been communicated better.