feat(docker): unify dynamic PORT across Dockerfile, compose, and dev server

.env.example

@@ -1,4 +1,5 @@
-# River Rooks Blog Environment Template
+# Environment Template
 # Copy to .env and adjust variables as needed:
 SITE_DOMAIN=riverrooks.dev
 SITE_URL=https://riverrooks.dev
+PORT=8080

Dockerfile

@@ -5,9 +5,10 @@ WORKDIR /app
 # Dynamic build arguments & environment variables
 ARG SITE_DOMAIN
 ARG SITE_URL
+ARG PORT=8080
 ENV SITE_DOMAIN=$SITE_DOMAIN
 ENV SITE_URL=$SITE_URL
-ENV PORT=8080
+ENV PORT=$PORT
 ENV NODE_ENV=production
 
 # Install dependencies
@@ -20,8 +21,8 @@ COPY . .
 # Build static production assets
 RUN npm run build
 
-# Expose web server port
-EXPOSE 8080
+# Expose web server port dynamically
+EXPOSE ${PORT}
 
 # Serve site with npm
 CMD ["npm", "start"]

docker-compose.yml

@@ -8,16 +8,18 @@ services:
       args:
         SITE_DOMAIN: ${SITE_DOMAIN:?Error: SITE_DOMAIN is not set. Please define SITE_DOMAIN in .env}
         SITE_URL: ${SITE_URL:-https://${SITE_DOMAIN}}
+        PORT: ${PORT:-8080}
     image: river-rooks-blog:latest
     container_name: river_rooks_web
     restart: unless-stopped
     environment:
       - SITE_DOMAIN=${SITE_DOMAIN:?Error: SITE_DOMAIN is not set. Please define SITE_DOMAIN in .env}
       - SITE_URL=${SITE_URL:-https://${SITE_DOMAIN}}
+      - PORT=${PORT:-8080}
     ports:
-      - "8080:8080"
+      - "${HOST_PORT:-${PORT:-8080}}:${PORT:-8080}"
     healthcheck:
-      test: ["CMD", "wget", "-qO-", "http://localhost:8080/healthz"]
+      test: ["CMD", "wget", "-qO-", "http://localhost:${PORT:-8080}/healthz"]
       interval: 30s
       timeout: 5s
       retries: 3

eleventy.config.js

@@ -62,6 +62,11 @@ export default function (eleventyConfig) {
     return [...tagSet].sort();
   });
 
+  // 6. Dev Server Options (dynamic port binding)
+  eleventyConfig.setServerOptions({
+    port: parseInt(process.env.PORT || "8080", 10)
+  });
+
   return {
     dir: {
       input: "src",

test/docker-config.test.js

@@ -18,7 +18,9 @@ test("Docker Configuration: Dockerfile enforces Node runtime and excludes Nginx"
 
   // Must build static site and serve with npm
   assert.match(content, /RUN\s+npm\s+run\s+build/, "Dockerfile must run npm build");
-  assert.match(content, /EXPOSE\s+8080/, "Dockerfile must expose port 8080");
+  assert.match(content, /ARG\s+PORT=8080/, "Dockerfile must define ARG PORT with default fallback");
+  assert.match(content, /ENV\s+PORT=\$\{?PORT\}?/, "Dockerfile must define ENV PORT using variable");
+  assert.match(content, /EXPOSE\s+\$\{?PORT\}?/, "Dockerfile must expose dynamic PORT variable");
   assert.match(content, /CMD\s*\[\s*["']npm["']\s*,\s*["']start["']\s*\]/, "Dockerfile must start via npm start");
 });
 
@@ -28,11 +30,12 @@ test("Docker Configuration: docker-compose.yml configures Node service correctly
 
   const content = fs.readFileSync(composePath, "utf-8");
 
-  // Verifies port mapping to 8080
-  assert.match(content, /8080:8080/, "docker-compose.yml must map port 8080 to container 8080");
+  // Verifies dynamic port mapping and environment variables
+  assert.match(content, /PORT:\s*\$\{PORT:-8080\}/, "docker-compose.yml must pass dynamic PORT build arg and env");
+  assert.match(content, /:\$\{PORT:-8080\}/, "docker-compose.yml must map dynamic container PORT");
 
-  // Verifies healthcheck targets 8080
-  assert.match(content, /localhost:8080/, "Healthcheck must probe port 8080");
+  // Verifies healthcheck targets dynamic port
+  assert.match(content, /localhost:\$\{PORT:-8080\}\/healthz/, "Healthcheck must probe dynamic PORT on /healthz");
 
   // Verifies domain argument enforcement
   assert.match(content, /SITE_DOMAIN/, "docker-compose.yml must require SITE_DOMAIN");