docker: deployment (#543)

.github/workflows/docker.yml

@@ -0,0 +1,55 @@
+name: Build & Push
+# Build & Push builds the simapp docker image on every push to master and
+# and pushes the image to https://hub.docker.com/r/interchainio/simapp/tags
+on:
+  pull_request:
+  push:
+    branches:
+      - master
+    tags:
+      - "v[0-9]+.[0-9]+.[0-9]+" # Push events to matching v*, i.e. v1.0, v20.15.10
+      - "v[0-9]+.[0-9]+.[0-9]+-rc*" # Push events to matching v*, i.e. v1.0-rc1, v20.15.10-rc5
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@master
+        with:
+          fetch-depth: 0
+
+      - name: Prepare
+        id: prep
+        run: |
+          DOCKER_IMAGE=tendermint/gaia
+          VERSION=noop
+          if [[ $GITHUB_REF == refs/tags/* ]]; then
+            VERSION=${GITHUB_REF#refs/tags/}
+          elif [[ $GITHUB_REF == refs/heads/* ]]; then
+            VERSION=$(echo ${GITHUB_REF#refs/heads/} | sed -r 's#/+#-#g')
+            if [ "${{ github.event.repository.default_branch }}" = "$VERSION" ]; then
+              VERSION=latest
+            fi
+          fi
+          TAGS="${DOCKER_IMAGE}:${VERSION}"
+          if [[ $VERSION =~ ^v[0-9]{1,3}\.[0-9]{1,3}\.[0-9]{1,3}$ ]]; then
+            TAGS="$TAGS,${DOCKER_IMAGE}:${VERSION}"
+          fi
+          echo ::set-output name=version::${VERSION}
+          echo ::set-output name=tags::${TAGS}
+          echo ::set-output name=created::$(date -u +'%Y-%m-%dT%H:%M:%SZ')
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to DockerHub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Publish to Docker Hub
+        uses: docker/build-push-action@v2
+        with:
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.prep.outputs.tags }}