1. 介绍
Compose项目是Docker官方开源的项目，负责实现对 Docker 容器集群的快速编排。用于定义和运行多容器 Docker 应用程序的工具。通过 Compose，您可以使用 YML 文件来配置应用程序需要的所有服务。然后，使用一个命令，就可以从 YML 文件配置中创建并启动所有服务。
Compose 中有两个重要的概念：
- 服务 (
service)：一个应用的容器，实际上可以包括若干运行相同镜像的容器实例。 - 项目 (
project)：由一组关联的应用容器组成的一个完整业务单元，在docker-compose.yml文件中定义。
2. 安装
mac 和 windows不需要单独安装
linux 安装
compose v2 下载地址 projiect release page
Run the following command to download the current stable release of Docker Compose:
mkdir -p ~/.docker/cli-plugins/ curl -SL https://github.com/docker/compose/releases/download/v2.0.0/docker-compose-linux-amd64 -o ~/.docker/cli-plugins/docker-compose如果为所有用户安装将
~/.docker/cli-plugins替换为/usr/local/lib/docker/cli-plugins.Apply executable permissions to the binary
chmod +x ~/.docker/cil-plugins/docker-composeTest installation
docker compose version
3. 基础语法和使用
version: "3.8"
services: # 容器
servicename: # 服务名字，这个名字也是内部 bridge网络可以使用的 DNS name
image: # 镜像的名字
command: # 可选，如果设置，则会覆盖默认镜像里的 CMD命令
environment: # 可选，相当于 docker run里的 --env
volumes: # 可选，相当于docker run里的 -v
networks: # 可选，相当于 docker run里的 --network
ports: # 可选，相当于 docker run里的 -p
build: # 可选，build dockerfile
servicename2:
volumes: # 可选，相当于 docker volume create
networks: # 可选，相当于 docker network create
命令和选项
Docker Compose
Options:
--ansi string Control when to print ANSI control characters ("never"|"always"|"auto") (default "auto")
--compatibility Run compose in backward compatibility mode
--env-file string Specify an alternate environment file.
-f, --file stringArray Compose configuration files
--profile stringArray Specify a profile to enable
--project-directory string Specify an alternate working directory
(default: the path of the Compose file)
-p, --project-name string Project name
Commands:
build Build or rebuild services
convert Converts the compose file to platform's canonical format
cp Copy files/folders between a service container and the local filesystem
create Creates containers for a service.
down Stop and remove containers, networks
events Receive real time events from containers.
exec Execute a command in a running container.
images List images used by the created containers
kill Force stop service containers.
logs View output from containers
ls List running compose projects
pause pause services
port Print the public port for a port binding.
ps List containers
pull Pull service images
push Push service images
restart Restart containers
rm Removes stopped service containers
run Run a one-off command on a service.
start Start services
stop Stop services
top Display the running processes
unpause unpause services
up Create and start containers
启动一个compose
文件docker-compose.yml当前目录/home/yemo/dockerTest 。如需后台运行使用docker compose up -d
❯ docker compose up
[+] Running 7/7
⠿ redis-server Pulled 20.5s
⠿ 07aded7c29c6 Pull complete 7.4s
⠿ 1a5d64c027a4 Pull complete
[+] Running 3/3
⠿ Network dockertest_demo-network Created 0.2s
⠿ Container dockertest-nginx-demo-1 Created 0.5s
⠿ Container dockertest-redis-server-1 Created 0.5s
docker compose 生成的容器名称会使用当前目录作为前缀
4. 服务更新
吧需要build的重新build,如果镜像发生了改变就会build
docker copose up --build
5. 网络
6. 水平扩展 scale
web2镜像信息: web镜像构建和代码
目录
- web
- nginx
- nginx.conf
- docker-compose.yml
- nginx
docker-compose.yml
version: "3"
services:
web:
image: web2
networks:
- demo-network
nginx:
image: nginx
ports:
- 80:80
depends_on:
- web
volumes:
- ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf:ro
- ./var/log/nginx:/var/log/nginx
networks:
- demo-network
networks:
demo-network:
nginx.conf
server {
listen 80 default_server;
location / {
proxy_pass http://web:8080;
}
}
运行
-d后台运行。
❯ docker compose up -d --scale web=3
[+] Running 4/4
⠿ Container web-web-1 Running 0.0s
⠿ Container web-web-3 Running 0.0s
⠿ Container web-web-2 Running 0.0s
⠿ Container web-nginx-1 Started
使用curl 请求
❯ curl 127.0.0.1
351
yemo@yemo ~/dockerTest/web
❯ curl 127.0.0.1
760
yemo@yemo ~/dockerTest/web
❯ curl 127.0.0.1
519
yemo@yemo ~/dockerTest/web
❯ curl 127.0.0.1
351
yemo@yemo ~/dockerTest/web
❯ curl 127.0.0.1
760
7. 环境变量 environment
environment设置环境变量。你可以使用数组或字典两种格式。
environment:
- REDIS_PASS=abc123
- REDIS_NAME=${REDIS_NAME}
使用文件导入，在docker-compose文件目录下创建.env
.env
REDIS_NAME=myName
如果不想使用默认名字.env可以使用env_file命令指定文件
docker-compose --env-file 文件
8. 服务依赖和健康检查
healthcheck通过命令检查容器是否健康运行
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:8080"]
interval: 30s
timeout: 3s
retries: 3
start_period: 40s
docker compose文件
version: "3"
services:
web:
image: web2
build:
context: ./
# build那个dockerfile文件
dockerfile: dockerfile
networks:
- demo-network
# 通过命令检查容器是否健康运行
healthcheck:
test: ["CMD", "curl", "-f", "http://localhost:8080"]
interval: 30s
timeout: 3s
retries: 3
start_period: 40s
nginx:
image: nginx
ports:
- 80:80
# 启动顺序
depends_on:
# - wbe
# 如果web服务不是healthy就不启动
web:
condition: service_healthy
volumes:
- ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf:ro
- ./var/log/nginx:/var/log/nginx
networks:
- demo-network
networks:
demo-network: