Fix log file issues

- when running in docker, php-fpm child proceses can't write to log
  files which are symbolic linked to /dev/stderr.  seems to be
  related to permissions and how cake/php uses fopen when writing to
  pipes.
- this fix create pipes before starting the php-fpm master process.
  these pipes are redirected to stderr

Dockerfile

@@ -18,19 +18,18 @@ RUN apt-get update && apt-get install --no-install-recommends --no-install-sugge
 
 COPY docker/php.ini /usr/local/etc/php/
 COPY . /var/www/html
+COPY docker/docker-entrypoint-php-fpm.sh /
 
 RUN cd /var/www/html \
     && composer install --no-ansi --no-dev --no-interaction --no-plugins --no-progress --no-suggest --optimize-autoloader \
     && mkdir -p /var/www/html/app/tmp/cache/persistent /var/www/html/app/tmp/cache/models /var/www/html/app/tmp/logs \
     && chown www-data:www-data -R /var/www/html/app/tmp/cache \
-    && ln -sf /dev/stdout /var/www/html/app/tmp/logs/api.log \
-    && ln -sf /dev/stdout /var/www/html/app/tmp/logs/debug.log \
-    && ln -sf /dev/stdout /var/www/html/app/tmp/logs/login.log \
-    && ln -sf /dev/stderr /var/www/html/app/tmp/logs/error.log
+    && chown www-data:www-data -R /var/www/html/app/tmp/logs
 
 RUN set -ex \
     ## Customize PHP fpm configuration
     && sed -i -e "s/;clear_env\s*=\s*no/clear_env = no/g" /usr/local/etc/php-fpm.conf \
     && sed -i -e "s/;request_terminate_timeout\s*=[^\n]*/request_terminate_timeout = 300/g" /usr/local/etc/php-fpm.conf \
     && php-fpm --test
 
+CMD ["/docker-entrypoint-php-fpm.sh"]

docker/docker-entrypoint-php-fpm.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+
+# hacks to allow php-fpm child process to write to log files that redirected to stderr
+# similar to https://github.com/moby/moby/issues/6880#issuecomment-344114520
+chown www-data:www-data /var/www/html/app/tmp/logs
+for f in /var/www/html/app/tmp/logs/api.log \
+    /var/www/html/app/tmp/logs/debug.log \
+    /var/www/html/app/tmp/logs/error.log \
+    /var/www/html/app/tmp/logs/login.log
+do
+    rm -f $f
+    mkfifo -m 600 $f
+    chown www-data:www-data $f
+    cat <> $f 1>&2 &
+done
+
+php-fpm