Day 12: Isolating My Flask App with Docker Compose Like a 2025 DevOps Pro!

Today, I dove into Docker Compose project names and namespaces to isolate my Flask + Redis app environments. Spoiler: it’s like giving each app its own VIP room at a tech party!

What’s the Big Deal with Project Names?

Imagine running your app in dev and test environments on the same machine without them stepping on each other’s toes. That’s where Docker Compose project names come in! They create namespaces—unique prefixes for containers, networks, and volumes—so your dev and test setups don’t get into a fistfight. I used --project-name to keep my Flask + Redis app’s environments as separate as my coffee and code (both essential, never mixed!).

Hands-On: Isolating My Flask + Redis App

I kicked off by revisiting my Day 11 setup: a Flask app with Redis, custom networks, health checks, and profiles. My goal? Spin up isolated dev and test environments. Here’s how I did it:

1. Set the Stage: I navigated to my ~/tmp/flask-redis-app directory and checked my docker-compose.yml. It’s got all the goodies: health checks (/health), custom networks (app-net), and profiles (dev, prod). No 404s or 500s here, thanks to Day 9–11 fixes!

2. Created a Test Environment: I copied my app to ~/tmp/flask-redis-app-test and tweaked its .env file:

    APP_TITLE=Test Flask App
    REDIS_PASSWORD=supersecretpassword
   

   I also updated the web service port to 5001:5000 to avoid conflicts with dev’s 5000.

3. Fired Up Isolated Environments:

   • Dev environment: docker compose --profile dev up -d --build (default project name: flask-redis-app).

   • Test environment: docker compose --project-name flask-test --profile dev up -d --build.

   • Result? Containers like flask-redis-app_web_1 and flask-test_web_1, plus separate networks (flask-redis-app_app-net, flask-test_app-net). Isolation achieved!

4. Tested the Waters: I hit curl http://localhost:5000 (dev) and got “App from .env: Visited 1 times.” For test, curl http://localhost:5001 returned “Test Flask App: Visited 1 times.” Health checks? curl http://localhost:5000/health said “OK” for both. No crosstalk—pure isolation magic!

5. Prod Profile Bonus: I tested the prod profile in dev (docker compose --profile prod up -d) and hit localhost:8080. Boom—“Production Flask App: Visited 2 times.” Clean and modular!

6. Cleaned Up: Shut it all down with docker compose down and docker compose --project-name flask-test down. No clutter left behind.

Playing with Commands and Grok

Next, I got hands-on with isolation commands:

• docker compose ps to list project-specific containers.

• docker compose --project-name test-env up -d to spin up another test environment.

• docker network ls to confirm separate networks.

I also had a blast with Grok (free tier on grok.com, of course). I asked, “Explain Docker Compose project namespaces in 100 words,” and got a crisp breakdown. Then, I used DeepSearch to hunt for 2025 X posts on project names—found a gem from @docker about namespace best practices! I even tried think mode for a step-by-step isolation guide. Grok’s like my tech sidekick, keeping me sharp!