Getting output from cron-executed script into syslog / docker logging facility

[JT Zemp]

Hi, Passenger Docker peeps.

I've got a simple/quick test app that adds a script to the /home/app directory and a line to /etc/crontab that runs it every minute. The script outputs to stdout and syslog. The entries end up in /var/log/syslog inside the container, but aren't accessible via `docker logs -f $container`. Any thoughts on what I'm doing wrong or where to look next to see if it's a bug?

Thanks!

Dockerfile:

FROM phusion/passenger-ruby23:0.9.22

ENV HOME /root

CMD ["/sbin/my_init"]

COPY echo_me.sh cron_definition /home/app/

RUN cat /home/app/cron_definition >> /etc/crontab

echo_me.sh

#!/usr/bin/env bash

MESSAGE="I'm a script running in Docker cron. Kinda like Chaka Khan, but different. $(date)"

echo $MESSAGE >> log

logger $MESSAGE

echo "STDOUT ${MESSAGE}"

cron_definition

# every minute of every day for the rest of your life, run this script as the

# `app` user.

* * * * * app /home/app/echo_me.sh

When I build/run the image:

% docker build -t "docker-cron-test" .

% docker run "docker-cron-test"

*** Running /etc/my_init.d/00_regen_ssh_host_keys.sh...

*** Running /etc/my_init.d/30_presetup_nginx.sh...

*** Running /etc/rc.local...

*** Booting runit daemon...

*** Runit started as PID 9

I don't see any output here ^^

I can see that syslog is writing my output to the log

% docker exec -ti zealous_bartik bash -l

root@3f2c9ea0546e:/# less /var/log/syslog

root@3f2c9ea0546e:/# cat !$

cat /var/log/syslog

Aug 14 22:09:05 3f2c9ea0546e syslog-ng[16]: syslog-ng starting up; version='3.5.6'

Aug 14 22:10:01 3f2c9ea0546e CRON[25]: (app) CMD (/home/app/echo_me.sh)

Aug 14 22:10:01 3f2c9ea0546e app: I'm a script running in Docker cron. Kinda like Chaka Khan, but different. Mon Aug 14 22:10:01 UTC 2017

Aug 14 22:10:01 3f2c9ea0546e CRON[24]: (CRON) info (No MTA installed, discarding output)

But it's not getting out to docker logs:

% docker logs -f zealous_bartik

*** Running /etc/my_init.d/00_regen_ssh_host_keys.sh...

*** Running /etc/my_init.d/30_presetup_nginx.sh...

*** Running /etc/rc.local...

*** Booting runit daemon...

*** Runit started as PID 9

Thoughts?

Thanks!