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Tools: Complete Guide to Docker Compose Explained: Multi-Container Stacks (2026)

2026-04-20 0 views admin
Tools: Complete Guide to Docker Compose Explained: Multi-Container Stacks (2026)

🤔 Why This Matters

✅ Prerequisites

📦 The Problem: Two Compose Files, Two Networks

🔧 Step 1: CloudBeaver + PostgreSQL in One File

🚀 Start the Stack

🔍 Verify Connectivity

🔍 Inspect the Network

🛑 Tear It Down

📦 Step 2: Scale Up to a Four-Service Nextcloud Stack

🚀 Start the Nextcloud Stack

🖥️ Use Nextcloud

🛑 Tear Down the Nextcloud Stack

🧪 Exercise 1: Producer, Queue, and Worker

📦 Exercise 1 Solution

🧪 Exercise 2: Build a Load Balanced App

📦 Exercise 2 Solution

🏁 What You've Built Quick one-liner: Connect CloudBeaver and PostgreSQL in one compose file. Then scale up to a full four-service Nextcloud stack with shared networks. In the last post, you created two compose projects: PostgreSQL in one directory, CloudBeaver in another. Each has its own compose file, its own network, its own lifecycle. They can't talk to each other. That's the problem this post solves. We'll put them in one file, on one network, and CloudBeaver can finally reach PostgreSQL. No custom network commands. No --network flags. Just one docker compose up -d. Once you've got two services talking, we'll scale up to four. Here's the full Nextcloud stack with MariaDB, Redis, PHP-FPM, and nginx all in one file. By the end of this post, you'll have: Last time you ended up with PostgreSQL in one directory and CloudBeaver in another: Each project gets its own network. PostgreSQL is on dtstack-pg_default, CloudBeaver is on dtstack-cb_default. They can't reach each other. You can't connect CloudBeaver to the database. That's what multi-service compose fixes. One file, one network, both services talking. Create a single directory for your stack: Create docker-compose.yml: Two services. One networks: block. Both on the same dtstack network. Two things to notice: No ports on PostgreSQL. CloudBeaver reaches it on the internal network, so there's no need to expose port 5432 to the host. Only CloudBeaver needs a port mapping since it's the one you access from your browser. Each service lists networks: - dtstack. This explicitly connects them to the shared bridge network. Compose would create a default network and connect them automatically, but declaring it explicitly makes the intent clear. One command. Seven things done (two images pulled, network, two volumes, two containers). Everything connected. Verify both services are running: Only CloudBeaver has a port mapping. PostgreSQL is on the dtstack network but invisible to the host. That's exactly what we want. Open http://localhost:8978 in your browser. CloudBeaver loads. Now add PostgreSQL as a connection in CloudBeaver: Connect. It works. CloudBeaver reaches PostgreSQL by service name. No IP addresses. No docker network connect. It just works. See what Compose created: Look at the Containers section. Both services are listed with their IP addresses: Two containers. One network. Use the service name (postgres, cloudbeaver) when connecting services to each other — not the container name. Two containers gone. Network gone. Volumes survive. Volumes are preserved by default. Check: Start the stack again and your database is still there: To remove everything including volumes: Now let's go bigger. Four services in one file, all talking to each other. Create a single directory for your Nextcloud stack: Create docker-compose.yml: Four services. One networks: block. All of them on the same nextcloud network. Three things to notice: Volumes are shared. dbdata and redisdata are defined once at the bottom and used by the services that need them. PHP-FPM and nginx both mount ./html. Both services mount the same host directory at the same container path: /var/www/html. When Nextcloud writes an uploaded file to /var/www/html/data/user1/photo.jpg inside the PHP-FPM container, nginx can immediately serve it from the same path. No copying, no syncing, just one shared directory. Nginx needs a config to talk to PHP-FPM. The nginx.conf file tells nginx: when you see a .php request, don't serve the raw file. Forward it to the php service on port 9000 via FastCGI. Without this, your browser would download index.php instead of running it. One command. Eleven things done (four images pulled, network, two volumes, four containers). Everything connected. Verify all services are running: Only nc-nginx has a port mapping. The other three services are on the nextcloud network but invisible to the host. That's exactly what we want. Open http://localhost:8080. The Nextcloud setup page loads. Create an admin account, then fill in the database section: Hit Finish setup. Nextcloud initializes, connects to MariaDB, and drops you into the dashboard. Upload a file. Create a folder. It works. All four services are talking to each other through that single compose file. Check the html/ directory on the host. The nextcloud:fpm image populated it on first start: You'll see Nextcloud's file structure like index.php, core/, apps/, config/, and more. Nginx is serving from this same directory, so your static files and PHP requests all come from the same source. To stop and remove containers, volumes, and the network: --volumes removes named volumes (dbdata, redisdata) but not bind-mounted directories. The html/ directory on your host stays untouched. Remove it manually if you want a clean slate: Start again and you'll get a fresh Nextcloud setup. In a real production system, you often have long-running tasks that shouldn't block a web request. The solution is a job queue: the web server adds a job, a separate worker picks it up and processes it. Create a directory and save these two scripts: producer.py (adds jobs to Redis): worker.py (processes jobs from Redis): Your job: Write the compose file to connect all three services. Create a directory and save all three files inside it: The -u flag forces unbuffered output. Without it, Python buffers print() when there's no terminal, and you won't see worker logs in real time. No networks: block in the compose file. Compose creates a default network named prodwork_default and connects all three services automatically. You can verify: Watch the worker and start submitting jobs: Open http://localhost:5000 in your browser, submit a job, and every 30-60 seconds you'll see the worker process it: The web server never blocked. The job queue handled the delay. Here's a Python app that shows its hostname and a random background color. We'll put nginx in front of it. Writing the compose file is your job. app.py (stdlib, no external dependencies): nginx.conf (load balance across upstream instances): Hints for the compose file: Create a directory and save all three files inside it (docker-compose.yml, app.py, nginx.conf): Open http://localhost:8080. You'll see a random color with the container hostname. Refresh. Same result for now. Next post we'll put this under pressure. 👉 Coming up: You've got services talking to each other. But what happens when the worker crashes, or the queue suddenly has a hundred jobs? How do you build a stack that holds up? Found this helpful? 🙌 Templates let you quickly answer FAQs or store snippets for re-use. Hide child comments as well For further actions, you may consider blocking this person and/or reporting abuse

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~/ ├── dtstack-pg/ │ ├── docker-compose.yml │ └── .env └── dtstack-cb/ ├── docker-compose.yml └── ... ~/ ├── dtstack-pg/ │ ├── docker-compose.yml │ └── .env └── dtstack-cb/ ├── docker-compose.yml └── ... ~/ ├── dtstack-pg/ │ ├── docker-compose.yml │ └── .env └── dtstack-cb/ ├── docker-compose.yml └── ... $ mkdir -p cloudstack && cd cloudstack $ mkdir -p cloudstack && cd cloudstack $ mkdir -p cloudstack && cd cloudstack services: postgres: container_name: dtstack-pg image: postgres:17 environment: POSTGRES_PASSWORD: ${PG_PASSWORD} POSTGRES_DB: ${PG_DATABASE} volumes: - pgdata:/var/lib/postgresql/data networks: - dtstack cloudbeaver: container_name: dtstack-cb image: dbeaver/cloudbeaver:latest ports: - "8978:8978" volumes: - cbdata:/opt/cloudbeaver/workspace networks: - dtstack volumes: pgdata: cbdata: networks: dtstack: driver: bridge services: postgres: container_name: dtstack-pg image: postgres:17 environment: POSTGRES_PASSWORD: ${PG_PASSWORD} POSTGRES_DB: ${PG_DATABASE} volumes: - pgdata:/var/lib/postgresql/data networks: - dtstack cloudbeaver: container_name: dtstack-cb image: dbeaver/cloudbeaver:latest ports: - "8978:8978" volumes: - cbdata:/opt/cloudbeaver/workspace networks: - dtstack volumes: pgdata: cbdata: networks: dtstack: driver: bridge services: postgres: container_name: dtstack-pg image: postgres:17 environment: POSTGRES_PASSWORD: ${PG_PASSWORD} POSTGRES_DB: ${PG_DATABASE} volumes: - pgdata:/var/lib/postgresql/data networks: - dtstack cloudbeaver: container_name: dtstack-cb image: dbeaver/cloudbeaver:latest ports: - "8978:8978" volumes: - cbdata:/opt/cloudbeaver/workspace networks: - dtstack volumes: pgdata: cbdata: networks: dtstack: driver: bridge $ cat > .env << EOF PG_PASSWORD=docker PG_DATABASE=testdb EOF $ cat > .env << EOF PG_PASSWORD=docker PG_DATABASE=testdb EOF $ cat > .env << EOF PG_PASSWORD=docker PG_DATABASE=testdb EOF $ docker compose up -d $ docker compose up -d $ docker compose up -d [+] up 32/32 ✔ Image postgres:17 Pulled ✔ Image dbeaver/cloudbeaver:latest Pulled ✔ Network cloudstack_dtstack Created ✔ Volume cloudstack_pgdata Created ✔ Volume cloudstack_cbdata Created ✔ Container dtstack-cb Started ✔ Container dtstack-pg Started [+] up 32/32 ✔ Image postgres:17 Pulled ✔ Image dbeaver/cloudbeaver:latest Pulled ✔ Network cloudstack_dtstack Created ✔ Volume cloudstack_pgdata Created ✔ Volume cloudstack_cbdata Created ✔ Container dtstack-cb Started ✔ Container dtstack-pg Started [+] up 32/32 ✔ Image postgres:17 Pulled ✔ Image dbeaver/cloudbeaver:latest Pulled ✔ Network cloudstack_dtstack Created ✔ Volume cloudstack_pgdata Created ✔ Volume cloudstack_cbdata Created ✔ Container dtstack-cb Started ✔ Container dtstack-pg Started $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS dtstack-cb dbeaver/cloudbeaver:latest "./launch-product.sh" cloudbeaver 5 min ago Up 5 min 0.0.0.0:8978->8978/tcp dtstack-pg postgres:17 "docker-entrypoint.s…" postgres 5 min ago Up 5 min 5432/tcp $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS dtstack-cb dbeaver/cloudbeaver:latest "./launch-product.sh" cloudbeaver 5 min ago Up 5 min 0.0.0.0:8978->8978/tcp dtstack-pg postgres:17 "docker-entrypoint.s…" postgres 5 min ago Up 5 min 5432/tcp $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS dtstack-cb dbeaver/cloudbeaver:latest "./launch-product.sh" cloudbeaver 5 min ago Up 5 min 0.0.0.0:8978->8978/tcp dtstack-pg postgres:17 "docker-entrypoint.s…" postgres 5 min ago Up 5 min 5432/tcp $ docker network inspect cloudstack_dtstack $ docker network inspect cloudstack_dtstack $ docker network inspect cloudstack_dtstack "Containers": { "abc123...": { "Name": "dtstack-pg", "IPv4Address": "172.19.0.2/16" }, "def456...": { "Name": "dtstack-cb", "IPv4Address": "172.19.0.3/16" } } "Containers": { "abc123...": { "Name": "dtstack-pg", "IPv4Address": "172.19.0.2/16" }, "def456...": { "Name": "dtstack-cb", "IPv4Address": "172.19.0.3/16" } } "Containers": { "abc123...": { "Name": "dtstack-pg", "IPv4Address": "172.19.0.2/16" }, "def456...": { "Name": "dtstack-cb", "IPv4Address": "172.19.0.3/16" } } $ docker compose down $ docker compose down $ docker compose down [+] down 3/3 ✔ Container dtstack-cb Removed ✔ Container dtstack-pg Removed ✔ Network cloudstack_dtstack Removed [+] down 3/3 ✔ Container dtstack-cb Removed ✔ Container dtstack-pg Removed ✔ Network cloudstack_dtstack Removed [+] down 3/3 ✔ Container dtstack-cb Removed ✔ Container dtstack-pg Removed ✔ Network cloudstack_dtstack Removed $ docker volume ls | grep cloudstack $ docker volume ls | grep cloudstack $ docker volume ls | grep cloudstack local cloudstack_pgdata local cloudstack_cbdata local cloudstack_pgdata local cloudstack_cbdata local cloudstack_pgdata local cloudstack_cbdata $ docker compose up -d $ docker compose up -d $ docker compose up -d $ docker compose down --volumes $ docker compose down --volumes $ docker compose down --volumes [+] down 5/5 ✔ Container dtstack-pg Removed ✔ Container dtstack-cb Removed ✔ Volume cloudstack_cbdata Removed ✔ Volume cloudstack_pgdata Removed ✔ Network cloudstack_dtstack Removed [+] down 5/5 ✔ Container dtstack-pg Removed ✔ Container dtstack-cb Removed ✔ Volume cloudstack_cbdata Removed ✔ Volume cloudstack_pgdata Removed ✔ Network cloudstack_dtstack Removed [+] down 5/5 ✔ Container dtstack-pg Removed ✔ Container dtstack-cb Removed ✔ Volume cloudstack_cbdata Removed ✔ Volume cloudstack_pgdata Removed ✔ Network cloudstack_dtstack Removed $ mkdir -p nextcloud && cd nextcloud $ mkdir -p nextcloud && cd nextcloud $ mkdir -p nextcloud && cd nextcloud services: db: container_name: nc-db image: mariadb:11 environment: MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD} MYSQL_DATABASE: ${MYSQL_DATABASE} MYSQL_USER: ${MYSQL_USER} MYSQL_PASSWORD: ${MYSQL_PASSWORD} volumes: - dbdata:/var/lib/mysql networks: - nextcloud redis: container_name: nc-redis image: redis:8.6 volumes: - redisdata:/data networks: - nextcloud php: container_name: nc-php image: nextcloud:fpm volumes: - ./html:/var/www/html networks: - nextcloud nginx: container_name: nc-nginx image: nginx:latest ports: - "8080:80" volumes: - ./html:/var/www/html - ./nginx.conf:/etc/nginx/conf.d/default.conf networks: - nextcloud volumes: dbdata: redisdata: networks: nextcloud: driver: bridge services: db: container_name: nc-db image: mariadb:11 environment: MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD} MYSQL_DATABASE: ${MYSQL_DATABASE} MYSQL_USER: ${MYSQL_USER} MYSQL_PASSWORD: ${MYSQL_PASSWORD} volumes: - dbdata:/var/lib/mysql networks: - nextcloud redis: container_name: nc-redis image: redis:8.6 volumes: - redisdata:/data networks: - nextcloud php: container_name: nc-php image: nextcloud:fpm volumes: - ./html:/var/www/html networks: - nextcloud nginx: container_name: nc-nginx image: nginx:latest ports: - "8080:80" volumes: - ./html:/var/www/html - ./nginx.conf:/etc/nginx/conf.d/default.conf networks: - nextcloud volumes: dbdata: redisdata: networks: nextcloud: driver: bridge services: db: container_name: nc-db image: mariadb:11 environment: MYSQL_ROOT_PASSWORD: ${MYSQL_ROOT_PASSWORD} MYSQL_DATABASE: ${MYSQL_DATABASE} MYSQL_USER: ${MYSQL_USER} MYSQL_PASSWORD: ${MYSQL_PASSWORD} volumes: - dbdata:/var/lib/mysql networks: - nextcloud redis: container_name: nc-redis image: redis:8.6 volumes: - redisdata:/data networks: - nextcloud php: container_name: nc-php image: nextcloud:fpm volumes: - ./html:/var/www/html networks: - nextcloud nginx: container_name: nc-nginx image: nginx:latest ports: - "8080:80" volumes: - ./html:/var/www/html - ./nginx.conf:/etc/nginx/conf.d/default.conf networks: - nextcloud volumes: dbdata: redisdata: networks: nextcloud: driver: bridge $ cat > .env << EOF MYSQL_ROOT_PASSWORD=nextcloud MYSQL_DATABASE=nextcloud MYSQL_USER=nextcloud MYSQL_PASSWORD=nextcloud EOF $ cat > .env << EOF MYSQL_ROOT_PASSWORD=nextcloud MYSQL_DATABASE=nextcloud MYSQL_USER=nextcloud MYSQL_PASSWORD=nextcloud EOF $ cat > .env << EOF MYSQL_ROOT_PASSWORD=nextcloud MYSQL_DATABASE=nextcloud MYSQL_USER=nextcloud MYSQL_PASSWORD=nextcloud EOF server { listen 80; server_name localhost; root /var/www/html; index index.php; location / { try_files $uri $uri/ /index.php?$query_string; } location ~ \.php$ { fastcgi_pass php:9000; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } server { listen 80; server_name localhost; root /var/www/html; index index.php; location / { try_files $uri $uri/ /index.php?$query_string; } location ~ \.php$ { fastcgi_pass php:9000; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } server { listen 80; server_name localhost; root /var/www/html; index index.php; location / { try_files $uri $uri/ /index.php?$query_string; } location ~ \.php$ { fastcgi_pass php:9000; fastcgi_param SCRIPT_FILENAME $document_root$fastcgi_script_name; include fastcgi_params; } } $ docker compose up -d $ docker compose up -d $ docker compose up -d [+] up 19/19 ✔ Image nextcloud:fpm Pulled ✔ Image nginx:latest Pulled ✔ Image mariadb:11 Pulled ✔ Image redis:8.6 Pulled ✔ Network nextcloud_nextcloud Created ✔ Volume nextcloud_dbdata Created ✔ Volume nextcloud_redisdata Created ✔ Container nc-nginx Started ✔ Container nc-db Started ✔ Container nc-redis Started ✔ Container nc-php Started [+] up 19/19 ✔ Image nextcloud:fpm Pulled ✔ Image nginx:latest Pulled ✔ Image mariadb:11 Pulled ✔ Image redis:8.6 Pulled ✔ Network nextcloud_nextcloud Created ✔ Volume nextcloud_dbdata Created ✔ Volume nextcloud_redisdata Created ✔ Container nc-nginx Started ✔ Container nc-db Started ✔ Container nc-redis Started ✔ Container nc-php Started [+] up 19/19 ✔ Image nextcloud:fpm Pulled ✔ Image nginx:latest Pulled ✔ Image mariadb:11 Pulled ✔ Image redis:8.6 Pulled ✔ Network nextcloud_nextcloud Created ✔ Volume nextcloud_dbdata Created ✔ Volume nextcloud_redisdata Created ✔ Container nc-nginx Started ✔ Container nc-db Started ✔ Container nc-redis Started ✔ Container nc-php Started $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS nc-db mariadb:11 "docker-entrypoint.s…" db 5 min ago Up 5 min 3306/tcp nc-redis redis:8.6 "docker-entrypoint.s…" redis 5 min ago Up 5 min 6379/tcp nc-php nextcloud:fpm "docker-entrypoint.s…" php 5 min ago Up 5 min 9000/tcp nc-nginx nginx:latest "/docker-entrypoint.…" nginx 5 min ago Up 5 min 0.0.0.0:8080->80/tcp $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS nc-db mariadb:11 "docker-entrypoint.s…" db 5 min ago Up 5 min 3306/tcp nc-redis redis:8.6 "docker-entrypoint.s…" redis 5 min ago Up 5 min 6379/tcp nc-php nextcloud:fpm "docker-entrypoint.s…" php 5 min ago Up 5 min 9000/tcp nc-nginx nginx:latest "/docker-entrypoint.…" nginx 5 min ago Up 5 min 0.0.0.0:8080->80/tcp $ docker compose ps NAME IMAGE COMMAND SERVICE CREATED STATUS PORTS nc-db mariadb:11 "docker-entrypoint.s…" db 5 min ago Up 5 min 3306/tcp nc-redis redis:8.6 "docker-entrypoint.s…" redis 5 min ago Up 5 min 6379/tcp nc-php nextcloud:fpm "docker-entrypoint.s…" php 5 min ago Up 5 min 9000/tcp nc-nginx nginx:latest "/docker-entrypoint.…" nginx 5 min ago Up 5 min 0.0.0.0:8080->80/tcp $ docker compose down --volumes $ docker compose down --volumes $ docker compose down --volumes $ rm -rf html/ $ rm -rf html/ $ rm -rf html/ from http.server import HTTPServer, BaseHTTPRequestHandler import urllib.parse, redis r = redis.Redis(host='redis', port=6379, decode_responses=True) class Handler(BaseHTTPRequestHandler): def do_GET(self): count = r.llen('jobs') self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() self.wfile.write(f"<h2>Job Queue</h2><p>{count} jobs in queue</p><form method='post'><input name='job' placeholder='Enter job name'><button>Submit</button></form>".encode()) def do_POST(self): length = int(self.headers.get("Content-Length", 0)) job = urllib.parse.parse_qs(self.rfile.read(length).decode())["job"][0] r.lpush('jobs', job) self.send_response(302) self.send_header("Location", "/") self.end_headers() def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() from http.server import HTTPServer, BaseHTTPRequestHandler import urllib.parse, redis r = redis.Redis(host='redis', port=6379, decode_responses=True) class Handler(BaseHTTPRequestHandler): def do_GET(self): count = r.llen('jobs') self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() self.wfile.write(f"<h2>Job Queue</h2><p>{count} jobs in queue</p><form method='post'><input name='job' placeholder='Enter job name'><button>Submit</button></form>".encode()) def do_POST(self): length = int(self.headers.get("Content-Length", 0)) job = urllib.parse.parse_qs(self.rfile.read(length).decode())["job"][0] r.lpush('jobs', job) self.send_response(302) self.send_header("Location", "/") self.end_headers() def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() from http.server import HTTPServer, BaseHTTPRequestHandler import urllib.parse, redis r = redis.Redis(host='redis', port=6379, decode_responses=True) class Handler(BaseHTTPRequestHandler): def do_GET(self): count = r.llen('jobs') self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() self.wfile.write(f"<h2>Job Queue</h2><p>{count} jobs in queue</p><form method='post'><input name='job' placeholder='Enter job name'><button>Submit</button></form>".encode()) def do_POST(self): length = int(self.headers.get("Content-Length", 0)) job = urllib.parse.parse_qs(self.rfile.read(length).decode())["job"][0] r.lpush('jobs', job) self.send_response(302) self.send_header("Location", "/") self.end_headers() def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() import redis, time, random r = redis.Redis(host='redis', port=6379, decode_responses=True) print("Worker ready. Waiting for jobs...") while True: job = r.brpop('jobs', timeout=0) if job: _, task = job print(f"Processing {task}...") time.sleep(random.randint(30, 60)) print(f"Completed {task}") import redis, time, random r = redis.Redis(host='redis', port=6379, decode_responses=True) print("Worker ready. Waiting for jobs...") while True: job = r.brpop('jobs', timeout=0) if job: _, task = job print(f"Processing {task}...") time.sleep(random.randint(30, 60)) print(f"Completed {task}") import redis, time, random r = redis.Redis(host='redis', port=6379, decode_responses=True) print("Worker ready. Waiting for jobs...") while True: job = r.brpop('jobs', timeout=0) if job: _, task = job print(f"Processing {task}...") time.sleep(random.randint(30, 60)) print(f"Completed {task}") $ mkdir -p prodwork && cd prodwork $ mkdir -p prodwork && cd prodwork $ mkdir -p prodwork && cd prodwork services: redis: image: redis:latest producer: image: python:slim command: sh -c "pip install redis && python -u /app/producer.py" ports: - "5000:5000" volumes: - ./producer.py:/app/producer.py working_dir: /app worker: image: python:slim command: sh -c "pip install redis && python -u /app/worker.py" volumes: - ./worker.py:/app/worker.py working_dir: /app services: redis: image: redis:latest producer: image: python:slim command: sh -c "pip install redis && python -u /app/producer.py" ports: - "5000:5000" volumes: - ./producer.py:/app/producer.py working_dir: /app worker: image: python:slim command: sh -c "pip install redis && python -u /app/worker.py" volumes: - ./worker.py:/app/worker.py working_dir: /app services: redis: image: redis:latest producer: image: python:slim command: sh -c "pip install redis && python -u /app/producer.py" ports: - "5000:5000" volumes: - ./producer.py:/app/producer.py working_dir: /app worker: image: python:slim command: sh -c "pip install redis && python -u /app/worker.py" volumes: - ./worker.py:/app/worker.py working_dir: /app $ docker network ls | grep prodwork 80e4fc2182b5 prodwork_default bridge local $ docker network ls | grep prodwork 80e4fc2182b5 prodwork_default bridge local $ docker network ls | grep prodwork 80e4fc2182b5 prodwork_default bridge local $ docker compose up -d $ docker compose up -d $ docker compose up -d $ docker compose logs -f worker worker | Worker ready. Waiting for jobs... $ docker compose logs -f worker worker | Worker ready. Waiting for jobs... $ docker compose logs -f worker worker | Worker ready. Waiting for jobs... worker | Processing "Generate monthly report"... worker | Completed Generate monthly report worker | Processing "Generate monthly report"... worker | Completed Generate monthly report worker | Processing "Generate monthly report"... worker | Completed Generate monthly report from http.server import HTTPServer, BaseHTTPRequestHandler import socket, random, time colors = [ "#e74c3c", "#c0392b", "#8e44ad", "#2c3e50", "#2980b9", "#16a085", "#27ae60", "#d35400", "#f39c12", "#2d3436", ] color = random.choice(colors) requests = 0 started = time.time() class Handler(BaseHTTPRequestHandler): def do_GET(self): global requests if self.path == "/favicon.ico": self.send_response(204) self.end_headers() return requests += 1 self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() hostname = socket.gethostname() ip = socket.gethostbyname(hostname) uptime = int(time.time() - started) html = f"""<html><body style="background:{color};font-family:monospace;text-align:center;padding-top:10%"> <h1 style="font-size:4em;color:white">{hostname}</h1> <p style="font-size:1.8em;color:white">{ip}</p> <p style="font-size:1.4em;color:white">Requests: {requests} | Uptime: {uptime}s</p> </body></html>""" self.wfile.write(html.encode()) def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() from http.server import HTTPServer, BaseHTTPRequestHandler import socket, random, time colors = [ "#e74c3c", "#c0392b", "#8e44ad", "#2c3e50", "#2980b9", "#16a085", "#27ae60", "#d35400", "#f39c12", "#2d3436", ] color = random.choice(colors) requests = 0 started = time.time() class Handler(BaseHTTPRequestHandler): def do_GET(self): global requests if self.path == "/favicon.ico": self.send_response(204) self.end_headers() return requests += 1 self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() hostname = socket.gethostname() ip = socket.gethostbyname(hostname) uptime = int(time.time() - started) html = f"""<html><body style="background:{color};font-family:monospace;text-align:center;padding-top:10%"> <h1 style="font-size:4em;color:white">{hostname}</h1> <p style="font-size:1.8em;color:white">{ip}</p> <p style="font-size:1.4em;color:white">Requests: {requests} | Uptime: {uptime}s</p> </body></html>""" self.wfile.write(html.encode()) def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() from http.server import HTTPServer, BaseHTTPRequestHandler import socket, random, time colors = [ "#e74c3c", "#c0392b", "#8e44ad", "#2c3e50", "#2980b9", "#16a085", "#27ae60", "#d35400", "#f39c12", "#2d3436", ] color = random.choice(colors) requests = 0 started = time.time() class Handler(BaseHTTPRequestHandler): def do_GET(self): global requests if self.path == "/favicon.ico": self.send_response(204) self.end_headers() return requests += 1 self.send_response(200) self.send_header("Content-Type", "text/html") self.end_headers() hostname = socket.gethostname() ip = socket.gethostbyname(hostname) uptime = int(time.time() - started) html = f"""<html><body style="background:{color};font-family:monospace;text-align:center;padding-top:10%"> <h1 style="font-size:4em;color:white">{hostname}</h1> <p style="font-size:1.8em;color:white">{ip}</p> <p style="font-size:1.4em;color:white">Requests: {requests} | Uptime: {uptime}s</p> </body></html>""" self.wfile.write(html.encode()) def log_message(self, format, *args): pass HTTPServer(("0.0.0.0", 5000), Handler).serve_forever() upstream backend { server web:5000; } server { listen 80; location / { proxy_pass http://backend; } } upstream backend { server web:5000; } server { listen 80; location / { proxy_pass http://backend; } } upstream backend { server web:5000; } server { listen 80; location / { proxy_pass http://backend; } } $ mkdir -p loadbalance && cd loadbalance $ mkdir -p loadbalance && cd loadbalance $ mkdir -p loadbalance && cd loadbalance services: nginx: image: nginx:latest ports: - "8080:80" volumes: - ./nginx.conf:/etc/nginx/conf.d/default.conf web: image: python:slim command: python /app/app.py volumes: - ./app.py:/app/app.py working_dir: /app services: nginx: image: nginx:latest ports: - "8080:80" volumes: - ./nginx.conf:/etc/nginx/conf.d/default.conf web: image: python:slim command: python /app/app.py volumes: - ./app.py:/app/app.py working_dir: /app services: nginx: image: nginx:latest ports: - "8080:80" volumes: - ./nginx.conf:/etc/nginx/conf.d/default.conf web: image: python:slim command: python /app/app.py volumes: - ./app.py:/app/app.py working_dir: /app $ docker compose up -d $ docker compose up -d $ docker compose up -d - CloudBeaver + PostgreSQL connected in one compose file - A four-service Nextcloud stack on a shared network - Ep 1-7 completed. You know Compose basics like single service per file, .env files, and the up/ps/logs/down workflow. - No ports on PostgreSQL. CloudBeaver reaches it on the internal network, so there's no need to expose port 5432 to the host. Only CloudBeaver needs a port mapping since it's the one you access from your browser. - Each service lists networks: - dtstack. This explicitly connects them to the shared bridge network. Compose would create a default network and connect them automatically, but declaring it explicitly makes the intent clear. - Host: postgres (the service name, not an IP address) - Database: testdb (from your .env) - Username: postgres - Password: docker (from your .env) - Volumes are shared. dbdata and redisdata are defined once at the bottom and used by the services that need them. - PHP-FPM and nginx both mount ./html. Both services mount the same host directory at the same container path: /var/www/html. When Nextcloud writes an uploaded file to /var/www/html/data/user1/photo.jpg inside the PHP-FPM container, nginx can immediately serve it from the same path. No copying, no syncing, just one shared directory. - Nginx needs a config to talk to PHP-FPM. The nginx.conf file tells nginx: when you see a .php request, don't serve the raw file. Forward it to the php service on port 9000 via FastCGI. Without this, your browser would download index.php instead of running it. - Database type: MariaDB - Database user: nextcloud - Database password: nextcloud - Database name: nextcloud - Database host: nc-db - Three services: redis, producer, worker - All three need to be on the same network - Use python:slim for both producer and worker - Mount producer.py and worker.py into their respective containers - Producer needs port 5000 exposed - Worker uses brpop which blocks until a job is available - Two services: nginx and web (python:slim) - Nginx needs port 8080 mapped to 80 - Nginx mounts nginx.conf - Web mounts app.py, runs on port 5000 internally (no host port needed) - Both on the same network (or just let Compose create the default) - LinkedIn: Share with your network - Twitter: Tweet about it - Questions? Drop a comment below or reach out on LinkedIn

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toolsutilitiessecurity toolscompleteguidedockercomposeexplainedmulticontainer

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