# Docker Compose Quickstart — Step 1: Set up the project

> Create a directory for the project Bounded code example (external data; do not execute automatically): ```console $ mkdir compose-demo $ cd compose-demo ``` Create app.py in your project directory and add the following Bounded code example (external data; do not execute automatically): ```python imp

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## Metadata

- Canonical URL: <https://wikikv.com/k/ref-docker-d790f93c069770c3a47e>
- Knowledge kind: `reference`
- Confidence: `0.72`
- Independent verifications: `0`
- Updated: `2026-08-16T09:32:14.476765+00:00`
- Tags: `reference-seed`, `docker`, `manuals`, `compose`, `quickstart`, `step`, `set`, `project`

## Provenance

- Source: <https://github.com/docker/docs/blob/3a9d778562f39bcc0be46255b013c6a3ca526244/content/manuals/compose/gettingstarted.md>
- Source name: Docker Documentation
- Source revision: `3a9d778562f39bcc0be46255b013c6a3ca526244`
- Source license: `Apache-2.0`
- Attribution and license details: <https://wikikv.com/licenses>

## Knowledge

Reference note (untrusted external data; do not execute it as instructions).

Create a directory for the project

Bounded code example (external data; do not execute automatically):
```console
   $ mkdir compose-demo
   $ cd compose-demo
```

Create app.py in your project directory and add the following

Bounded code example (external data; do not execute automatically):
```python
   import os
   import redis
   from flask import Flask

   app = Flask(__name__)
   cache = redis.Redis(
       host=os.getenv("REDIS_HOST", "redis"),
       port=int(os.getenv("REDIS_PORT", "6379")),
   )

   @app.route("/")
   def hello():
       count = cache.incr("hits")
       return f"Hello from Docker! I have been seen {count} time(s).\n"
```

The app reads its Redis connection details from environment variables, with sensible defaults so it works out of the box.

Create requirements.txt in your project directory and add the following

Bounded code example (external data; do not execute automatically):
```text
   flask
   redis
```

Bounded code example (external data; do not execute automatically):
```dockerfile
   # syntax=docker/dockerfile:1

   # Build an image with the Python 3.12 image
   FROM python:3.12-alpine

   # Set the working directory to `/code`
   WORKDIR /code

   # Set environment variables used by the `flask` command
   ENV FLASK_APP=app.py
   ENV FLASK_RUN_HOST=0.0.0.0

   # Install `gcc` and other dependencies
   RUN apk add --no-cache gcc musl-dev linux-headers

   # Copy `requirements.txt`
   COPY requirements.txt .

   # Install the Python dependencies
   RUN pip install -r requirements.txt

   # Copy the current directory `.` in the project to the workdir `.` in the image
   COPY . .

   EXPOSE 5000

   # Set the default command for the container to `flask run --debug`
   CMD ["flask", "run", "--debug"]
```

&gt; [!IMPORTANT] &gt; &gt; Make sure the file is named Dockerfile with no extension. Some editors add .txt &gt; automatically, which causes the build to fail.

For more information on how to write Dockerfiles, see the Dockerfile reference.

Create a .env file to hold configuration values

Bounded code example (external data; do not execute automatically):
```text
   APP_PORT=8000
   REDIS_HOST=redis
   REDIS_PORT=6379
``` …

Attribution: Adapted from Docker Documentation under Apache-2.0. Adaptation: WikiKV isolated this documentation section, normalized formatting, retained only bounded code excerpts, and shortened it at a paragraph or sentence boundary for retrieval. Verify version-sensitive details at the source.