Add the Stack file for the demo

[refs #a456f8d3f09f]

swarm/swarm-demo/app.env

@@ -1,4 +1,4 @@
 POSTGRES_USER=demo
 POSTGRES_PASSWORD=secret
 POSTGRES_DB=demo
-POSTGRES_HOST=demo-db
+POSTGRES_HOST=db

swarm/swarm-demo/docker-stack.yml

@@ -0,0 +1,35 @@
+version: "3.3"
+
+services:
+  frontend:
+    image: jfahrer/swarm-demo-frontend:v5
+    env_file:
+      - app.env
+    deploy:
+      replicas: 10
+
+  db:
+    image: jfahrer/swarm-demo-db:v1
+    env_file:
+      - db.env
+    volumes:
+      - pg-data:/var/lib/postgresql/data
+    deploy:
+      resources:
+        reservations:
+          memory: 256M
+      placement:
+        constraints:
+          - node.hostname == node1
+
+  lb:
+    image: jfahrer/swarm-demo-lb:v1
+    environment:
+      - PROXY_UPSTREAM=frontend:8080
+    ports:
+      - 80:80
+    deploy:
+      replicas: 3
+
+volumes:
+  pg-data: