Ubuntu 中Docker Compose的奇淫异巧

我们需要安装 Docker 来安装 Docker Compose。首先为官方 Docker 仓库添加公钥。

$ curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add -

接下来，添加 Docker 仓库到 apt 源列表：

$ sudo add-apt-repository "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable"

更新包数据库，并使用 apt 安装 Docker

$ sudo apt-get update
$ sudo apt install docker-ce

在安装进程结束后，Docker 守护程序应该已经启动并设为开机自动启动。我们可以通过下面的命令来查看它的状态：

$ sudo systemctl status docker
---------------------------------

● docker.service - Docker Application Container Engine
Loaded: loaded (/lib/systemd/system/docker.service; enabled; vendor preset: enabled)
Active: active (running)

现在可以安装 Docker Compose 了。通过执行以下命令下载当前版本。

# curl -L https://github.com/docker/compose/releases/download/1.14.0/docker-compose-
`uname -s`-`uname -m` > /usr/local/bin/docker-compose

为二进制文件添加执行权限：

# chmod +x /usr/local/bin/docker-compose

检查 Docker Compose 版本：

$ docker-compose -v

输出应该如下：

docker-compose version 1.14.0, build c7bdf9e

Docker Hub 包含了一个用于演示的 Hello World 镜像，可以用来说明使用 Docker Compose 来运行一个容器所需的配置。

创建并打开一个目录：

$ mkdir hello-world $ cd hello-world

创建一个新的 YAML 文件：

$ $EDITOR docker-compose.yml

在文件中粘贴如下内容：

unixmen-compose-test:
image: hello-world

注意: 第一行是容器名称的一部分。
保存并退出。

接下来，在 hello-world 目录执行以下命令：

$ sudo docker-compose up

如果一切正常，Compose 输出应该如下：

Pulling unixmen-compose-test (hello-world:latest)...
latest: Pulling from library/hello-world
b04784fba78d: Pull complete
Digest: sha256:f3b3b28a45160805bb16542c9531888519430e9e6d6ffc09d72261b0d26ff74f
Status: Downloaded newer image for hello-world:latest
Creating helloworld_unixmen-compose-test_1 ...
Creating helloworld_unixmen-compose-test_1 ... done
Attaching to helloworld_unixmen-compose-test_1
unixmen-compose-test_1 |
unixmen-compose-test_1 | Hello from Docker!
unixmen-compose-test_1 | This message shows that your installation appears to be working correctly.
unixmen-compose-test_1 |
unixmen-compose-test_1 | To generate this message, Docker took the following steps:
unixmen-compose-test_1 | 1\. The Docker client contacted the Docker daemon.
unixmen-compose-test_1 | 2\. The Docker daemon pulled the "hello-world" image from the Docker Hub.
unixmen-compose-test_1 | 3\. The Docker daemon created a new container from that image which runs the
unixmen-compose-test_1 | executable that produces the output you are currently reading.
unixmen-compose-test_1 | 4\. The Docker daemon streamed that output to the Docker client, which sent it
unixmen-compose-test_1 | to your terminal.
unixmen-compose-test_1 |
unixmen-compose-test_1 | To try something more ambitious, you can run an Ubuntu container with:
unixmen-compose-test_1 | $ docker run -it ubuntu bash
unixmen-compose-test_1 |
unixmen-compose-test_1 | Share images, automate workflows, and more with a free Docker ID:
unixmen-compose-test_1 | https://cloud.docker.com/
unixmen-compose-test_1 |
unixmen-compose-test_1 | For more examples and ideas, visit:
unixmen-compose-test_1 | https://docs.docker.com/engine/userguide/
unixmen-compose-test_1 |
helloworld_unixmen-compose-test_1 exited with code 0 Docker

容器只能在命令（LCTT 译注：此处应为容器中的命令）还处于活动状态时运行，因此当测试完成运行时，容器将停止运行。

本文是关于在 Ubuntu 16.04 中安装 Docker Compose 的教程。我们还看到了如何通过一个 YAML 格式的 Compose 文件构建一个简单的项目。