入门示例
一般步骤
1、定义Dockerfile,方便迁移到任何地方;
2、编写docker-compose.yml文件;
3、运行docker-compose up
启动服务
示例
准备工作:提前下载好镜像:
docker pull mysql
docker pull wordpress
需要新建一个空白目录,例如wptest。新建一个docker-compose.yml
version: '2'
services:
web:
image: wordpress:latest
links:
- db
ports:
- "8002:80"
environment:
WORDPRESS_DB_HOST: db:3306
WORDPRESS_DB_PASSWORD: 123456
db:
image: mysql
environment:
- MYSQL_ROOT_PASSWORD=123456
以上命令的意思是新建db和wordpress容器。等同于:
$ docker run --name db -e MYSQL_ROOT_PASSWORD=123456 -d mysql
$ docker run --name some-wordpress --link db:mysql -p 8002:80 -d wordpress
注意,如果你是直接从fig迁移过来的,且
web
里links
是- db:mysql
,这里会提示没有给wordpress设置环境变量,这里需要添加环境变量WORDPRESS_DB_HOST
和WORDPRESS_DB_PASSWORD
。
好,我们启动应用:
# docker-compose up
Creating wptest_db_1...
Creating wptest_wordpress_1...
Attaching to wptest_db_1, wptest_wordpress_1
wordpress_1 | Complete! WordPress has been successfully copied to /var/www/html
就成功了。浏览器访问 http://localhost:8002(或 http://host-ip:8002)即可。
默认是前台运行并打印日志到控制台。如果想后台运行,可以:
docker-compose up -d
服务后台后,可以使用下列命令查看状态:
# docker-compose ps
Name Command State Ports
-----------------------------------------------------------------------------------
figtest_db_1 docker-entrypoint.sh mysqld Up 3306/tcp
figtest_wordpress_1 docker-entrypoint.sh apach ... Up 0.0.0.0:8002->80/tcp
# docker-compose logs
Attaching to wptest_wordpress_1, wptest_db_1
db_1 | 2016-10-4T14:38:46.98030Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server option (see documentation for more details).
db_1 | 2016-10-4T14:38:46.99974Z 0 [Note] mysqld (mysqld 5.7.15) starting as process 1 ...
db_1 | 2016-10-4T14:38:46.27191Z 0 [Note] InnoDB: PUNCH HOLE support available
停止服务:
# docker-compose stop
Stopping wptest_wordpress_1...
Stopping wptest_db_1...
重新启动服务:
docker-compose restart
docker-compose.yml参考
每个docker-compose.yml必须定义image
或者build
中的一个,其它的是可选的。
image
指定镜像tag或者ID。示例:
image: redis
image: ubuntu:14.04
image: tutum/influxdb
image: example-registry.com:4000/postgresql
image: a4bc65fd
注意,在
version 1
里同时使用image
和build
是不允许的,version 2
则可以,如果同时指定了两者,会将build
出来的镜像打上名为image
标签。
build
用来指定一个包含Dockerfile
文件的路径。一般是当前目录.
。Fig将build并生成一个随机命名的镜像。
注意,在
version 1
里bulid
仅支持值为字符串。version 2
里支持对象格式。
build: ./dir
build:
context: ./dir
dockerfile: Dockerfile-alternate
args:
buildno: 1
context
为路径,dockerfile
为需要替换默认docker-compose
的文件名,args
为构建(build)过程中的环境变量,用于替换Dockerfile里定义的ARG
参数,容器中不可用。示例:
Dockerfile:
ARG buildno
ARG password
RUN echo "Build number: $buildno"
RUN script-requiring-password.sh "$password"
docker-compose.yml:
build:
context: .
args:
buildno: 1
password: secret
build:
context: .
args:
- buildno=1
- password=secret
command
用来覆盖缺省命令。示例:
command: bundle exec thin -p 3000
command
也支持数组形式:
command: [bundle, exec, thin, -p, 3000]
links
用于链接另一容器服务,如需要使用到另一容器的mysql服务。可以给出服务名和别名;也可以仅给出服务名,这样别名将和服务名相同。同docker run --link
。示例:
links:
- db
- db:mysql
- redis
使用了别名将自动会在容器的/etc/hosts
文件里创建相应记录:
172.17.2.186 db
172.17.2.186 mysql
172.17.2.187 redis
所以我们在容器里就可以直接使用别名作为服务的主机名。
ports
用于暴露端口。同docker run -p
。示例:
ports:
- "3000"
- "8000:8000"
- "49100:22"
- "127.0.0.1:8001:8001"
expose
expose提供container之间的端口访问,不会暴露给主机使用。同docker run --expose
。
expose:
- "3000"
- "8000"
volumes
挂载数据卷。同docker run -v
。示例:
volumes:
- /var/lib/mysql
- cache/:/tmp/cache
- ~/configs:/etc/configs/:ro
volumes_from
挂载数据卷容器,挂载是容器。同docker run --volumes-from
。示例:
volumes_from:
- service_name
- service_name:ro
- container:container_name
- container:container_name:rw
container:container_name
格式仅支持version 2
。
environment
添加环境变量。同docker run -e
。可以是数组或者字典格式:
environment:
RACK_ENV: development
SESSION_SECRET:
environment:
- RACK_ENV=development
- SESSION_SECRET
depends_on
用于指定服务依赖,一般是mysql、redis等。
指定了依赖,将会优先于服务创建并启动依赖。
links
也可以指定依赖。
external_links
链接搭配docker-compose.yml
文件或者Compose
之外定义的服务,通常是提供共享或公共服务。格式与links
相似:
external_links:
- redis_1
- project_db_1:mysql
- project_db_1:postgresql
注意,
external_links
链接的服务与当前服务必须是同一个网络环境。
extra_hosts
添加主机名映射。
extra_hosts:
- "somehost:162.242.195.82"
- "otherhost:50.31.209.229"
将会在/etc/hosts
创建记录:
162.242.195.82 somehost
50.31.209.229 otherhost
extends
继承自当前yml文件或者其它文件中定义的服务,可以选择性的覆盖原有配置。
extends:
file: common.yml
service: webapp
service
必须有,file
可选。service
是需要继承的服务,例如web
、database
。
net
设置网络模式。同docker的--net
参数。
net: "bridge"
net: "none"
net: "container:[name or id]"
net: "host"
dns
自定义dns服务器。
dns: 8.8.8.8
dns:
- 8.8.8.8
- 9.9.9.9
cpu_shares, cpu_quota, cpuset, domainname, hostname, ipc, mac_address, mem_limit, memswap_limit, privileged, read_only, restart, shm_size, stdin_open, tty, user, working_dir
这些命令都是单个值,含义请参考docker run。
cpu_shares: 73
cpu_quota: 50000
cpuset: 0,1
user: postgresql
working_dir: /code
domainname: foo.com
hostname: foo
ipc: host
mac_address: 02:42:ac:11:65:43
mem_limit: 1000000000
mem_limit: 128M
memswap_limit: 2000000000
privileged: true
restart: always
read_only: true
shm_size: 64M
stdin_open: true
tty: true
命令行参考
$ docker-compose
Define and run multi-container applications with Docker.
Usage:
docker-compose [-f <arg>...] [options] [COMMAND] [ARGS...]
docker-compose -h|--help
Options:
-f, --file FILE Specify an alternate compose file (default: docker-compose.yml)
-p, --project-name NAME Specify an alternate project name (default: directory name)
--verbose Show more output
-v, --version Print version and exit
-H, --host HOST Daemon socket to connect to
--tls Use TLS; implied by --tlsverify
--tlscacert CA_PATH Trust certs signed only by this CA
--tlscert CLIENT_CERT_PATH Path to TLS certificate file
--tlskey TLS_KEY_PATH Path to TLS key file
--tlsverify Use TLS and verify the remote
--skip-hostname-check Don't check the daemon's hostname against the name specified
in the client certificate (for example if your docker host
is an IP address)
Commands:
build Build or rebuild services
bundle Generate a Docker bundle from the Compose file
config Validate and view the compose file
create Create services
down Stop and remove containers, networks, images, and volumes
events Receive real time events from containers
exec Execute a command in a running container
help Get help on a command
kill Kill containers
logs View output from containers
pause Pause services
port Print the public port for a port binding
ps List containers
pull Pulls service images
push Push service images
restart Restart services
rm Remove stopped containers
run Run a one-off command
scale Set number of containers for a service
start Start services
stop Stop services
unpause Unpause services
up Create and start containers
version Show the Docker-Compose version information
批处理脚本
# 关闭所有正在运行容器
docker ps | awk '{print $1}' | xargs docker stop
# 删除所有容器应用
docker ps -a | awk '{print $1}' | xargs docker rm
# 或者
docker rm $(docker ps -a -q)