install extra packages and extensions on first boot

build/start-container.sh

@@ -3,6 +3,17 @@
 # exit when any command fails
 set -e
 
+# install extra packages and extensions on first boot
+if [[ ! -f /etc/first_boot ]]; then
+    if [[ -n "${EXTRA_APK_PACKAGES// /}" ]]; then
+        apk add --no-cache "$EXTRA_APK_PACKAGES"
+    fi
+    if [[ -n "${EXTRA_PHP_EXTENSIONS// /}" ]]; then
+        docker-php-ext-install "$EXTRA_PHP_EXTENSIONS"
+    fi
+    touch /etc/first_boot
+fi
+
 if [[ "$BOOT_NPM_INSTALL" = true ]]; then
     echo "npm install"
     npm install

docker-compose.yml

@@ -16,6 +16,8 @@ services:
             BOOT_NPM_DEV: true # also starts `npm dev`
             BOOT_NPM_INSTALL: true # runs `npm install` on boot
             BOOT_COMPOSER_INSTALL: true # runs `composer install` on boot
+            #EXTRA_APK_PACKAGES: # string with extra packages to install on first boot example: "git python"
+            #EXTRA_PHP_EXTENSIONS: # string with extra php extensions to install on first boot
         depends_on:
             - mysql
             - redis