Add support for automated docker build

.github/workflows/docker.yml

@@ -0,0 +1,47 @@
+name: Publish Docker Image
+on:
+  push:
+    branches:
+      - 'develop'
+    tags:
+      - 'v*'
+jobs:
+  push_to_registry:
+    name: Push Image to GitHub Packages
+    runs-on: ubuntu-latest
+    # Always run against a tag, even if the commit into the tag has [docker skip]
+    # within the commit message.
+    if: "!contains(github.ref, 'develop') || (!contains(github.event.head_commit.message, 'skip docker') && !contains(github.event.head_commit.message, 'docker skip'))"
+    steps:
+      - uses: actions/checkout@v2
+      - uses: crazy-max/ghaction-docker-meta@v1
+        id: docker_meta
+        with:
+          images: ghcr.io/pterodactyl/wings
+      - uses: docker/setup-qemu-action@v1
+      - uses: docker/setup-buildx-action@v1
+      - uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.repository_owner }}
+          password: ${{ secrets.REGISTRY_TOKEN }}
+      - name: Release Production Build
+        uses: docker/build-push-action@v2
+        if: "!contains(github.ref, 'develop')"
+        env:
+          REF: ${{ github.ref }}
+        with:
+          push: true
+          build-args: |
+            VERSION=${REF:11}
+          tags: ${{ steps.docker_meta.outputs.tags }}
+          labels: ${{ steps.docker_meta.outputs.labels }}
+      - name: Release Development Build
+        uses: docker/build-push-action@v2
+        if: "contains(github.ref, 'develop')"
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          build-args: |
+            VERSION=dev-${GIT_COMMIT:0:7}
+          tags: ${{ steps.docker_meta.outputs.tags }}
+          labels: ${{ steps.docker_meta.outputs.labels }}