feat(): add PHP_EXTENSION env to install php extension

README.md

@@ -55,6 +55,7 @@
 | **OPCACHE_MEMORY_LIMIT** | OPcache memory size in megabytes | *optional* | 128
 | **LOG_TO_STDOUT** | Enable nginx and php error logs to stdout | *optional* | false
 | **GITHUB_TOKEN_AUTH** | Github token to download private extensions | *optional* | false
+| **PHP_EXTENSIONS** | Install additional php extensions | *optional* | none
 
 ### Required environment variable for first installation
 
@@ -148,6 +149,26 @@ docker-compose up -d flarum
 
 ![flarum-home](http://i.imgur.com/6kH9iTV.png)
 
+### Install additional php extensions
+
+```yml
+version: "3"
+
+services:
+  flarum:
+    image: mondedie/flarum:stable
+    container_name: flarum
+    environment:
+      - PHP_EXTENSIONS="gmp session brotli"
+    volumes:
+      - /mnt/docker/flarum/assets:/flarum/app/public/assets
+      - /mnt/docker/flarum/extensions:/flarum/app/extensions
+      - /mnt/docker/flarum/nginx:/etc/nginx/conf.d
+```
+
+This example install php7-gmp php7-session and php7-brotli with apk  
+You can find a php extension here https://pkgs.alpinelinux.org/packages?name=php7-*&branch=v3.12&arch=x86_64
+
 ### Install custom extensions
 
 **Flarum extensions list :** https://flagrow.io/extensions

rootfs/usr/local/bin/startup

@@ -31,6 +31,15 @@ if [ "${LOG_TO_STDOUT}" = true ]; then
   sed -i "s/.*error_log.*$/error_log = \/dev\/stdout/" /etc/php7/php-fpm.conf
 fi
 
+# Install additional php extensions
+if [ -n "${PHP_EXTENSIONS}" ]; then
+  for extension in ${PHP_EXTENSIONS}; do
+    PACKAGES="php7-${extension} ${PACKAGES}"
+  done
+
+  apk add --no-progress --no-cache ${PACKAGES}
+fi
+
 cd /flarum/app
 
 # add github token authentication (eg. for privates extensions)