refactor: Dockerfile stages, hadolint + CI

.github/workflows/main.yml

@@ -14,6 +14,14 @@ on:
   workflow_dispatch:
 
 jobs:
+  lint:
+    name: Lint Dockerfile
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: hadolint/[email protected]
+
   build:
     name: PHP
     runs-on: ubuntu-latest

.spells

@@ -0,0 +1,5 @@
+function hadolint() {
+  docker run --rm -i -v ./hadolint.yaml:/.config/hadolint.yaml hadolint/hadolint < Dockerfile
+}
+
+echo hadolint

Dockerfile

@@ -1,18 +1,18 @@
 ARG PHP_VERSION
 ARG PHP_EXTENSIONS
 
-FROM php:${PHP_VERSION}-fpm
+FROM mlocati/php-extension-installer:2 as extension-installer
+FROM php:${PHP_VERSION}-fpm as base
+FROM base
 
-WORKDIR /usr/local/etc/php/conf.d/
-COPY --link symfony.ini .
-WORKDIR /usr/local/etc/php/pool.d/
-COPY --link symfony.pool.conf .
+WORKDIR /usr/local/etc/php
+COPY --link symfony.ini ./conf.d/
+COPY --link symfony.pool.conf ./pool.d/
 
-ADD --chmod=0755 https://github.com/mlocati/docker-php-extension-installer/releases/latest/download/install-php-extensions /usr/local/bin/
+COPY --from=extension-installer /usr/bin/install-php-extensions /usr/local/bin
 
-RUN install-php-extensions ${PHP_EXTENSIONS}
+RUN install-php-extensions "${PHP_EXTENSIONS}"
 
-RUN usermod -u 1000 www-data
-RUN usermod -G staff www-data
+RUN usermod -u 1000 www-data && usermod -G staff www-data
 
 WORKDIR /var/www/symfony

hadolint.yaml

@@ -0,0 +1 @@
+failure-threshold: style