No way to get errors from php:7.2-fpm-alpine

[RoestVrijStaal]

Hi,

I stole a docker building for my own purpose: https://github.com/FabianMartin/docker-php-symfony/blob/master/alpine-php/7.2-xdebug

Unfortunately I got "connection reinitialised" at each time accessing the site via the browser (e.g. 127.0.0.1:9000). It's very hard to debug because I don't get any error messages from the php-fpm docker service.

I see php:7.2-fpm-alpine uses /proc/self/fd/2 and so do the files in the repository I linked above.

Unfortunately I don't get any errors in my console. Trying to let them output in /var/log/error.log in my container didn't work. /var/log/error.log isn't even created.

How to fix? Any ideas are welcome.

[wglambert]

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

php/7.2/alpine3.7/fpm/Dockerfile

Lines 190 to 200 in b9d625c

	echo '[global]'; \
	echo 'error_log = /proc/self/fd/2'; \
	echo; \
	echo '[www]'; \
	echo '; if we send this to /proc/self/fd/1, it never appears'; \
	echo 'access.log = /proc/self/fd/2'; \
	echo; \
	echo 'clear_env = no'; \
	echo; \
	echo '; Ensure worker stdout and stderr are sent to the main error log.'; \
	echo 'catch_workers_output = yes'; \

For why this is: #358 (comment)

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

[tianon]

Unfortunately I got "connection reinitialised" at each time accessing the site via the browser ...

When using the FPM variants, the 9000 port is not exposing the HTTP protocol, but is rather exposing the FastCGI protocol, so in order to do anything useful with it, you'll need something like NGINX or Apache in front translating HTTP requests to and from FastCGI.

There are also tools like cgi-fcgi which can be used to interact directly, but the experience is definitely going to be very raw (since again, a FastCGI server is not a "proper" web server by itself, but rather a lower-level building block for connecting other languages to a web server).

[RoestVrijStaal]

Hmmm, Since xdebug uses port 9000 by default (which i rather want not to change), I might not be interested in php-fpm (anymore).

@wglambert @tianon thanks for the help

[ThomasNegeli]

@RoestVrijStaal there is no problem with fpm and xdebug on port 9000.
xdebug is connecting to your host on port 9000. fpm is accepting connections on port 9000, but this is within your Docker Container.