Test Docker image build on pull-requests

.github/workflows/docker.yml

@@ -5,8 +5,24 @@ on:
   push:
     tags:
       - 'v*.*.*'
+  pull_request:
+    branches: [ main ]
 jobs:
+  test-image-build:
+    if: github.event.pull_request
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Build image
+        uses: docker/build-push-action@v3
+        with:
+          context: .
+          file: Dockerfile
+          push: false
+
   multiplatform-build:
+    if: ${{ ! github.event.pull_request }}
     runs-on: ubuntu-latest
     steps:
       - name: Checkout

Dockerfile

@@ -22,8 +22,7 @@ RUN apk --no-cache --update add \
     php81-pdo php81-pdo_mysql php81-pdo_sqlite php81-pdo_pgsql php81-mbstring php81-session php81-bcmath \
     php81-gd php81-openssl php81-sockets php81-posix php81-ldap php81-simplexml && \
     rm -rf /var/www/localhost && \
-    rm -f /etc/php81/php-fpm.d/www.conf && \
-    ln -s /usr/bin/php81 /usr/bin/php
+    rm -f /etc/php81/php-fpm.d/www.conf
 
 ADD . /var/www/app
 ADD docker/ /