> For the complete documentation index, see [llms.txt](https://hezhiqiang.gitbook.io/docker/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://hezhiqiang.gitbook.io/docker/compose/usage.md).

# 使用

## 术语

首先介绍几个术语。

* 服务 (`service`)：一个应用容器，实际上可以运行多个相同镜像的实例。
* 项目 (`project`)：由一组关联的应用容器组成的一个完整业务单元。

可见，一个项目可以由多个服务（容器）关联而成，`Compose` 面向项目进行管理。

## 场景

最常见的项目是 web 网站，该项目应该包含 web 应用和缓存。

下面我们用 `Python` 来建立一个能够记录页面访问次数的 web 网站。

### web 应用

新建文件夹，在该目录中编写 `app.py` 文件

```python
from flask import Flask
from redis import Redis

app = Flask(__name__)
redis = Redis(host='redis', port=6379)

@app.route('/')
def hello():
    count = redis.incr('hits')
    return 'Hello World! 该页面已被访问 {} 次。\n'.format(count)

if __name__ == "__main__":
    app.run(host="0.0.0.0", debug=True)
```

### Dockerfile

编写 `Dockerfile` 文件，内容为

```
FROM python:3.6-alpine
ADD . /code
WORKDIR /code
RUN pip install redis flask
CMD ["python", "app.py"]
```

### docker-compose.yml

编写 `docker-compose.yml` 文件，这个是 Compose 使用的主模板文件。

```yaml
version: '3'
services:

  web:
    build: .
    ports:
     - "5000:5000"

  redis:
    image: "redis:alpine"
```

### 运行 compose 项目

```bash
$ docker-compose up
```

此时访问本地 `5000` 端口，每次刷新页面，计数就会加 1。


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://hezhiqiang.gitbook.io/docker/compose/usage.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.