how to monitor a directory and include new files with tail -f in Centos(for shiny-server logs in Docker)

Question

Due to the need to direct shiny-server logs to stdout so that "docker logs" (and monitoring utilities relying on it) can see them i'm trying to do some kind of :

tail -f <logs_directory>/*

Which works as needed when no new files are added to the directory, the problem is shiny-server dynamically creates files in this directory which we need to automatically consider.

I found other users have solved this via the xtail package, the problem is i'm using Centos and xtail is not available for centos.

The question is , is there any "clean" way of doing this via standard tail command without needing xtail ? or maybe there exists an equivalent package to xtail for centos?

Answer 1

You will probably find it easier to use the docker run -v option to mount a host directory into the container and collect logs there. Then you can use any tool you want that collects log files out of a directory (logstash is popular but far from the only option) to collect those log files.

This also avoids the problem of having to both run your program and a log collector inside your container; you can just run the service as the main container process, and not have to do gymnastics with tail and supervisord and whatever else to try to keep everything running.