Error logs don't show in stdout

[roopemerikukka]

I'm getting only access logs to the stdout and at least I assume that the error logs should be shown in there also. Im using custom image FROM wordpress:php7.1-fpm-alpine which doesn't touch to any logging options (at least not purposely). The image that I'm using is: https://github.com/bond-agency/docker-wpbp-wordpress

Is there something wrong with the configuration of that image or do I have to turn the logging on separately?

[wglambert]

In the Dockerfile error_log and access.log are redirected to stderr not stdout.

https://github.com/docker-library/php/blob/master/7.2/alpine3.7/fpm/Dockerfile#L191

&& {
echo '[global]';
echo 'error_log = /proc/self/fd/2';
. . .
echo '[www]';
echo '; if we send this to /proc/self/fd/1, it never appears';
echo 'access.log = /proc/self/fd/2';
. . .
} | tee php-fpm.d/docker.conf \

For why this is: docker-library/php#358 (comment)

php-fpm likely closes STDOUT as part of its own startup routines.

[wglambert]

Issue seems resolved so going to close

[pentago]

Actually, the issue is not resolved, it's still present in 7.4.* images (haven't try 8.x branch).

[wglambert]

Because docker logs are read from /dev/stderr and /dev/stdout the log files redirect to stderr
docker-library/php#1174

Anything that would've been written to the error_log or access.log should show up in the docker logs output

[pentago]

Thing is, I don't use Docker, rather Docker container in Kubernetes. How does that impact PHP-FPM logging?

[wglambert]

It shouldn't? You're just using kubectl logs instead

For some more info about this nuance see docker-library/php#811 (comment)