Docker-Compose学习

介绍

熟悉Linux都知道，我们可以把很多相关的命令写成一个xxx.sh文件，而且这些步骤也是相对固定的。

这样直接运行sh文件，就可以逐一执行很多相关的Docker命令。这种形式可以减少出错和解决复用问题。Docker很贴心的为我们准备了一个专门的工具docker-compose，实现类似sh文件的功能。让我们更加轻松的实现多Docker命令的操作。

你也可以把docker-compose就是把很多Docker命令写入一个专属的文件docker-compose.yml，然后执行这个文件，就可以直接启动我们想要的容器。docker-compose也为我们提供了对应的操作命令。

docker-compose up
docker-compose stop

也就是说，操作docker-compose 会有两个大的部分需要操作:

第一部分是docker-compose.yam文件
输入命令执行构建容器

docker-compose.yaml介绍

yaml文件里是对启动镜像相关设置的所有描述，下面就逐一讲解一下。

version: "3.8" #表示使用的docker-compose的版本（注意要与docker版本对应）

codehope  ~  docker --version
Docker version 20.10.10, build b485636

https://docs.docker.com/compose/compose-file/

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
  	container_name: xxx
    image: xxx # 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
  servicename: # 其他服务名字
  	...

volumes: # 可选，相当于 docker volume create

networks: # 可选，相当于 docker network create

For exapmle

version: '3.8'

services:
  my-nginx: # 服务名字
    container_name: cw_my_ngxin # 镜像的名字
    image: nginx # 镜像的名字
    ports:
      - 80:80

初试-通过docker-compose启动nginx

docker-compose.yaml

version: '3.8'

services:
  nginx:
    image: nginx
    ports:
      - 80:80

codehope  ~/CunWangOwn/docke-file-test/docker-compose-demo  docker-compose up
Starting docker-compose-demo_nginx_1 ... done
Attaching to docker-compose-demo_nginx_1
nginx_1  | /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
nginx_1  | /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
nginx_1  | /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
nginx_1  | 10-listen-on-ipv6-by-default.sh: info: IPv6 listen already enabled
nginx_1  | /docker-entrypoint.sh: Launching /docker-entrypoint.d/20-envsubst-on-templates.sh
nginx_1  | /docker-entrypoint.sh: Launching /docker-entrypoint.d/30-tune-worker-processes.sh
nginx_1  | /docker-entrypoint.sh: Configuration complete; ready for start up
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: using the "epoll" event method
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: nginx/1.21.4
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: built by gcc 10.2.1 20210110 (Debian 10.2.1-6) 
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: OS: Linux 5.10.47-linuxkit
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: getrlimit(RLIMIT_NOFILE): 1048576:1048576
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: start worker processes
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: start worker process 25
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: start worker process 26
nginx_1  | 2021/11/28 13:17:57 [notice] 1#1: start worker process 27

访问宿主机 80端口，也是完全ok的！

命名规则

用docker compose创建的容器，名字都会加入一个对应文件夹的名字，比如我在的文件夹叫做 docker-compose-demo,而我在yaml文件中镜像的名字是nginx。

最终容器的名字就是docker-compose-demo_nginx_1

通过命令查看镜像和容器，拉取了一个nginx的镜像，并且以所在目录名称+镜像名称+序号的格式创建了容器

~/CunWangOwn/docke-file-test/docker-compose-demo  docker image ls -a
REPOSITORY                TAG       IMAGE ID       CREATED          SIZE
...
nginx                     latest    ea335eea17ab   11 days ago      141MB
...

~/CunWangOwn/docke-file-test/docker-compose-demo  docker container ls -a
CONTAINER ID   IMAGE      COMMAND                 CREATED        STATUS                      PORTS                    NAMES
811924c49ac1   nginx      "/docker-entrypoint.…"  5 minutes ago  Exited (137) 15 seconds ago                          docker-compose-demo_nginx_1

这个前缀其实是可以改的，比如我们希望前缀加上CunWangBro。就可以使用-p参数。【名称会自动帮我们转小写的】

docker-compose -p CunWangBro up 
Creating network "cunwangbro_default" with the default driver
Creating cunwangbro_nginx_1 ... done
Attaching to cunwangbro_nginx_1

查看container ls

 ~/CunWangOwn/docke-file-test/docker-compose-demo  docker container ls -a         
CONTAINER ID   IMAGE   COMMAND                 CREATED         STATUS                      PORTS                   NAMES
e7a9cca41daa   nginx   "/docker-entrypoint.…"  44 seconds ago  Exited (137) 3 seconds ago                          cunwangbro_nginx_1

你也可以在yaml文件里指定这个名字,方法是使用contaner_name: xxx但是这样作就会完全省略前缀和后缀。

version: '3.8'

services:
  my-nginx:
    container_name: cw_my_ngxin
    image: nginx
    ports:
      - 80:80

起！docker-compose up

~/CunWangOwn/docke-file-test/docker-compose-demo  docker-compose up              
WARNING: Found orphan containers (docker-compose-demo_nginx_1) for this project. If you removed or renamed this service in your compose file, you can run this command with the --remove-orphans flag to clean it up.
Creating cw_my_ngxin ... done
Attaching to cw_my_ngxin
cw_my_ngxin | /docker-entrypoint.sh: /docker-entrypoint.d/ is not empty, will attempt to perform configuration
cw_my_ngxin | /docker-entrypoint.sh: Looking for shell scripts in /docker-entrypoint.d/
cw_my_ngxin | /docker-entrypoint.sh: Launching /docker-entrypoint.d/10-listen-on-ipv6-by-default.sh
cw_my_ngxin | 10-listen-on-ipv6-by-default.sh: info: Getting the checksum of /etc/nginx/conf.d/default.conf

查看容器

docker container ls -a
CONTAINER ID   IMAGE    COMMAND                  CREATED        STATUS                    PORTS     NAMES
ff90b9191e44   nginx    "/docker-entrypoint.…"   3 minutes ago  Exited (0) 9 seconds ago            cw_my_ngxin

`docker-compose`构建自己的镜像

version: '3.8'

services:
  koa:
    image: koa-test:1.0
    ports: 
      - 8181:3000

这里的image: koa-test:1.0，是我们自己构建的镜像，但是目前还没有。如果用docker compose up 构建会直接报错。我们运行一下，可以看到下面的错误。

~/CunWangOwn/docke-file-test  docker-compose up
Pulling koa (koa-test:1.0)...
ERROR: The image for the service you're trying to recreate has been removed. If you continue, volume data could be lost. Consider backing up your data before continuing.

Continue with the new image? [yN]y
Pulling koa (koa-test:1.0)...
ERROR: pull access denied for koa-test, repository does not exist or may require 'docker login': denied: requested access to the resource is denied

意思就是这个my-node镜像在网上找不到，仓库里没有。

可以修改docker-compose.yml文件，让docker先构建镜像，然后再启动容器。

修改后的docker-compose.yml文件

文件目录结构

└── dockerfiledir
    ├── app.tar.gz
    └── dockerfile

docker-compose.yaml

version: '3.8'

services:
  cunwangkoa:
    container_name: cw_koa_server
    build: ./dockerfiledir
    image: koa-test:1.0
    ports: 
      - 8181:3000

dockerfile

FROM node:15.10.0-slim

ADD ./app.tar.gz  /app

WORKDIR /app

RUN npm install --registry=https://registry.npm.taobao.org 

CMD node app.js

然后起docker-compose 可以看到是先根据dockerfile文件 build的景象，然后再运行的服务,这时候就不会报错了，也可以正常启动容器了

 codehope  ~/CunWangOwn/docke-file-test  docker-compose up                 
Building cunwangkoa
[+] Building 3.1s (10/10) FINISHED                                                                                                                               
 => [internal] load build definition from Dockerfile                                                                                                        0.0s
 => => transferring dockerfile: 183B                                                                                                                        0.0s
 => [internal] load .dockerignore                                                                                                                           0.0s
 => => transferring context: 2B                                                                                                                             0.0s
 => [internal] load metadata for docker.io/library/node:15.10.0-slim                                                                                        3.0s
 => [auth] library/node:pull token for registry-1.docker.io                                                                                                 0.0s
 => [internal] load build context                                                                                                                           0.0s
 => => transferring context: 80B                                                                                                                            0.0s
 => [1/4] FROM docker.io/library/node:15.10.0-slim@sha256:325e465ccc8a02ada4db47e940c93b2734014cbed036db0a53d8ecc68abf0fc6                                  0.0s
 => CACHED [2/4] ADD ./app.tar.gz  /app                                                                                                                     0.0s
 => CACHED [3/4] WORKDIR /app                                                                                                                               0.0s
 => CACHED [4/4] RUN npm install --registry=https://registry.npm.taobao.org                                                                                 0.0s
 => exporting to image                                                                                                                                      0.0s
 => => exporting layers                                                                                                                                     0.0s
 => => writing image sha256:58127741dd2bd1d9427e606a07defe78637b42fb1ac0d273399d1486297019fe                                                                0.0s
 => => naming to docker.io/library/koa-test:1.0                                                                                                             0.0s

Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them
WARNING: Image for service cunwangkoa was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
Creating cw_koa_server ... done
Attaching to cw_koa_server
cw_koa_server | 村望老师的Docker测试服务器跑起来啦

查看镜像ls

 ~/CunWangOwn/docke-file-test  docker image ls -a          
REPOSITORY                TAG       IMAGE ID       CREATED        SIZE
koa-test                  1.0       58127741dd2b   2 hours ago    164MB

查看容器ls

~/CunWangOwn/docke-file-test  docker container ls -a          
CONTAINER ID  IMAGE         COMMAND                 CREATED             STATUS                       PORTS                NAMES
0ca15a2b8d7f  koa-test:1.0  "docker-entrypoint.s…"  About a minute ago  Exited (137) 40 seconds ago                       cw_koa_server

目录CONTENT

Docker-Compose学习

Docker-Compose学习

介绍

docker-compose.yaml介绍

初试-通过docker-compose启动nginx

命名规则

`docker-compose`构建自己的镜像

评论区

Docker-Compose学习

Docker-Compose学习

介绍

docker-compose.yaml介绍

初试-通过docker-compose启动nginx

命名规则

docker-compose构建自己的镜像

评论区

`docker-compose`构建自己的镜像