create a load-balancer

docker-compose.yml

@@ -3,4 +3,19 @@ services:
   todolist:
     build : . # (1)
     ports:
-      - 8081:8080 # (2)
+      - 8080 # (2)
+    deploy:
+      replicas: 3
+    labels:
+      - "traefik.http.routers.todolist.rule=PathPrefix(`/app`)"
+      - "traefik.http.middlewares.todolist.stripPrefix.prefixes=/app"
+      - "traefik.http.routers.todolist.middlewares=todolist@docker"
+  traefik:
+    image: traefik:2.5
+    restart: unless-stopped
+    ports:
+      - 80:80
+      - 8080:8080
+    volumes:
+      - /var/run/docker.sock:/var/run/docker.sock:ro
+      - ./traefik.toml:/traefik.toml

traefik.toml

@@ -0,0 +1,24 @@
+[global]
+sendAnonymousUsage = false
+
+[accessLog]
+
+[log]
+level = "DEBUG"
+format = "common"
+
+[providers]
+[providers.docker]
+endpoint = "unix:///var/run/docker.sock"
+watch = true
+exposedByDefault = true
+swarmMode = false
+
+[api]
+dashboard = true
+debug = false
+insecure = true
+
+[entryPoints]
+[entryPoints.insecure]
+address = ":80"