chore: update Dockerfile for building with diverse PHP versions (#67)

Modify the `Dockerfile` to enable building with different PHP versions.
Adjust the docker image build process to create images for all supported
PHP versions.

---------

Signed-off-by: Valentin Sickert <[email protected]>

.github/workflows/docker-image.yml

@@ -14,8 +14,13 @@ env:
 
 jobs:
   build-and-push-image:
+    name: Build and push Docker image for PHP ${{ matrix.php-version }}
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        php-version: ["8.1", "8.2", "8.3"]
+
     permissions:
       contents: read
       packages: write
@@ -36,6 +41,8 @@ jobs:
         uses: docker/metadata-action@31cebacef4805868f9ce9a0cb03ee36c32df2ac4 # v5
         with:
           images: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}
+          flavor: |
+            suffix=-php${{ matrix.php-version }}
           tags: |
             type=ref,event=branch
             type=semver,pattern={{version}}
@@ -49,3 +56,5 @@ jobs:
           push: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
+          build-args: |
+            PHP_VERSION=${{ matrix.php-version }}-apache

Dockerfile

@@ -1,5 +1,8 @@
+ARG COMPOSER_VERSION=lts
+ARG PHP_VERSION=8.1-apache
+
 # Stage 1: Build
-FROM composer:lts@sha256:0e7405d851433b5bb61c1783833b65e6b71fdab006c1029f42f2da1d670d53a5 as build
+FROM composer:${COMPOSER_VERSION} as build
 
 WORKDIR /app
 
@@ -9,7 +12,7 @@ COPY . /app/
 RUN composer install --prefer-dist --no-dev --optimize-autoloader --no-interaction --no-progress
 
 # Stage 2: Production
-FROM php:8.1-apache@sha256:3a2ed73364dbeecfdf9432550e294e5b989b182157ab2a56bd9c5a582504f4b6 as production
+FROM php:${PHP_VERSION} as production
 
 ENV APP_ENV=production
 ENV APP_DEBUG=false