add docker image

.github/workflows/build.yml

@@ -0,0 +1,43 @@
+name: Build Docker Image
+
+on:
+  push:
+    branches:
+      - 'main'
+  workflow_dispatch:
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - id: prep
+        name: find version
+        shell: bash
+        run: |
+          version=$(jq -r '.version' package.json)
+          echo "Found version: $version"
+          echo "version=$version" >> $GITHUB_OUTPUT
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v3
+
+      - name: Login to GHCR (GitHub Packages)
+        uses: docker/login-action@v3
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v5
+        with:
+          push: true
+          tags: |
+            ghcr.io/${{github.repository}}:latest
+            ghcr.io/${{github.repository}}:${{steps.prep.outputs.version}}

Dockerfile

@@ -0,0 +1,16 @@
+FROM node:20-alpine
+
+RUN apk add --no-cache bash tini
+
+EXPOSE 3000
+
+ENV CRANLIKE_MONGODB_SERVER="mongo" \
+    VCAP_APP_HOST="0.0.0.0"
+
+COPY . /frontend
+
+WORKDIR /frontend
+
+RUN npm install .
+
+ENTRYPOINT [ "tini", "--", "/frontend/entrypoint.sh"]

entrypoint.sh

@@ -0,0 +1,22 @@
+#!/bin/bash
+set -eo pipefail
+
+function wait_tcp_port {
+    local host="$1" port="$2"
+    local max_tries=5 tries=1
+
+    # see http://tldp.org/LDP/abs/html/devref1.html for description of this syntax.
+    while ! exec 6<>/dev/tcp/$host/$port && [[ $tries -lt $max_tries ]]; do
+        sleep 1s
+        tries=$(( tries + 1 ))
+        echo "$(date) retrying to connect to $host:$port ($tries/$max_tries)"
+    done
+    exec 6>&-
+}
+
+# wait for the mongo server to be available
+echo Waiting for ${CRANLIKE_MONGODB_SERVER}:${CRANLIKE_MONGODB_PORT:-27017}...
+wait_tcp_port "${CRANLIKE_MONGODB_SERVER}" "${CRANLIKE_MONGODB_PORT:-27017}"
+
+# run mongo-express
+exec npm start

package.json

@@ -1,7 +1,6 @@
 {
   "name": "express-frontend",
-  "version": "0.0.0",
-  "private": true,
+  "version": "1.0.0",
   "scripts": {
     "start": "node ./bin/www"
   },