Produce pretty lint results in GitHub Actions

Dockerfile

@@ -25,4 +25,5 @@ RUN ln -s /usr/share/php/PHP/CodeSniffer/bin/phpcs /usr/local/bin/phpcs && \
 
 USER user
 
-ENTRYPOINT ["/usr/bin/php", "/usr/local/bin/phpcs"]
+COPY entrypoint.sh /entrypoint.sh
+ENTRYPOINT ["/entrypoint.sh"]

Makefile

@@ -7,5 +7,5 @@ build:
 	$(DOCKER) build -t $(IMAGE) .
 
 run:
-	$(DOCKER) run --rm -it $(IMAGE)
+	$(DOCKER) run --rm -it $(IMAGE) --help
 

entrypoint.sh

@@ -0,0 +1,17 @@
+#!/bin/sh
+set -e
+
+EXTRA_ARGS=""
+EXTRA_PIPE=""
+
+#
+# If we're running in GitHub Actions, do some formatting
+#
+if [ -n "${GITHUB_ACTIONS}" ]
+then
+  EXTRA_ARGS="--report=checkstyle"
+  EXTRA_PIPE="| cs2pr"
+fi
+
+# Execute PHPCS
+/usr/bin/php /usr/local/bin/phpcs ${EXTRA_ARGS} "$@" ${EXTRA_PIPE}