Wait For Output

Waits for a pattern to match output of a command or docker container logs.

Features:

• Waiting for a pattern to appear in docker container logs
• Waiting for a generic command output to appear
• Finding container name by regexp pattern
• Returns result as a exit code and message
• Output of checked command/container log is passed through to the console

Installing

pip install waitforoutput

Usage with docker

--container takes a regexp expression, or a full container name. Output from container is streamed to the console until timeout is reached, at the end only result is displayed - the container is not killed.

If multiple containers are found the application will exit with an error.

$ waitforoutput 'Configuration complete; ready for start up' --container 'nginx_*' --timeout 5
/docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
/docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
/docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf
10-listen-on-ipv6-by-default.sh: info: Enabled listen on IPv6 in /etc/nginx/conf.d/default.conf
/docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
/docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
/docker-entrypoint.sh: Configuration complete; ready for start up
[2021-05-14 05:01:46.188][info]: Match found

Usage with any shell command

Command specified with --command parameter will be launched, and the waitforoutput will be streaming output until the --timeout is reached. After timeout the process will be killed.

$ waitforoutput 'Linux' --command 'uname -a'
Linux riotkit-dev 5.10.23-1-MANJARO #1 SMP PREEMPT Thu Mar 11 18:47:18 UTC 2021 x86_64 GNU/Linux
[2021-05-14 05:01:46.188][info]: Match found

Authors

Created by Riotkit anarchist tech-collective.