add entrypoint script

Dockerfile

@@ -31,4 +31,5 @@ RUN apt-get update && \
 	apt-get install -y docker-ce \
 	docker-ce-cli
 
-CMD ["goreleaser", "-v"]
+ENTRYPOINT ["/entrypoint.sh"]
+CMD ["-h"]

scripts/entrypoint.sh

@@ -0,0 +1,17 @@
+#!/usr/bin/env bash
+
+if [ -n "$DOCKER_USERNAME" ] && [ -n "$DOCKER_PASSWORD" ]; then
+    echo "Login to the docker..."
+    docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD $DOCKER_REGISTRY
+fi
+
+# Workaround for github actions when access to different repositories is needed.
+# Github actions provides a GITHUB_TOKEN secret that can only access the current
+# repository and you cannot configure it's value.
+# Access to different repositories is needed by brew for example.
+
+if [ -n "$GORELEASER_GITHUB_TOKEN" ] ; then
+  export GITHUB_TOKEN=$GORELEASER_GITHUB_TOKEN
+fi
+
+goreleaser $@