feat: allow configuration of mpm prefork in apache + mod_php

.env.docker

@@ -1264,6 +1264,46 @@ DOCKER_APP_HOST_CACHE_PATH="${DOCKER_ALL_HOST_DATA_ROOT_PATH:?error}/pixelfed/ca
 # @see https://www.php.net/manual/en/install.fpm.configuration.php#pm.max-spare-servers
 #DOCKER_APP_PHP_FPM_PM_MAX_SPARE_SERVERS="3"
 
+# The number of server processes to start
+#
+# Apache + PHP *ONLY*
+#
+# @default 5
+# @see https://httpd.apache.org/docs/2.4/mod/mpm_common.html#startservers
+#DOCKER_APP_PHP_PREFORK_START_SERVERS="5"
+
+# The minimum number of server processes which are kept spare
+#
+# Apache + PHP *ONLY*
+#
+# @default 5
+# @see https://httpd.apache.org/docs/2.4/mod/prefork.html#minspareservers
+#DOCKER_APP_PHP_PREFORK_MIN_SPARE_SERVERS="5"
+
+# The maximum number of server processes which are kept spare
+#
+# Apache + PHP *ONLY*
+#
+# @default 10
+# @see https://httpd.apache.org/docs/2.4/mod/prefork.html#maxspareservers
+#DOCKER_APP_PHP_PREFORK_MAX_SPARE_SERVERS="10"
+
+# The maximum number of server processes allowed to start
+#
+# Apache + PHP *ONLY*
+#
+# @default 150
+# @see https://httpd.apache.org/docs/2.4/mod/mpm_common.html#maxrequestworkers
+#DOCKER_APP_PHP_PREFORK_MAX_REQUEST_WORKERS="150"
+
+# The maximum number of requests a server process serves
+#
+# Apache + PHP *ONLY*
+#
+# @default 0
+# @see https://httpd.apache.org/docs/2.4/mod/mpm_common.html#maxconnectionsperchild
+#DOCKER_APP_PHP_PREFORK_MAX_CONNECTIONS_PER_CHILD="0"
+
 ################################################################################
 # docker redis
 ################################################################################

docker/rootfs/apache/docker/templates/etc/apache2/mods-enabled/mpm_prefork.conf

@@ -0,0 +1,12 @@
+# prefork MPM
+# StartServers: number of server processes to start
+# MinSpareServers: minimum number of server processes which are kept spare
+# MaxSpareServers: maximum number of server processes which are kept spare
+# MaxRequestWorkers: maximum number of server processes allowed to start
+# MaxConnectionsPerChild: maximum number of requests a server process serves
+
+StartServers            {{ getenv "DOCKER_APP_PHP_PREFORK_START_SERVERS" "5" }}
+MinSpareServers         {{ getenv "DOCKER_APP_PHP_PREFORK_MIN_SPARE_SERVERS" "5" }}
+MaxSpareServers         {{ getenv "DOCKER_APP_PHP_PREFORK_MAX_SPARE_SERVERS" "10" }}
+MaxRequestWorkers       {{ getenv "DOCKER_APP_PHP_PREFORK_MAX_REQUEST_WORKERS" "150" }}
+MaxConnectionsPerChild  {{ getenv "DOCKER_APP_PHP_PREFORK_MAX_CONNECTIONS_PER_CHILD" "0" }}