将应用和运行环境打包成一个镜像
为了数据安全,数据不能放在容器中
数据须要持久化存储
卷技术说白了,将容器内目录挂载到Linux中的目录,文件同步的机制
卷的目的:为了作持久化和同步,容器间也能够实现数据共享html
docker run -it -v 宿主机目录:容器内目录 centos /bin/bash
启动以后能够使用
docker inspect 容器id
查看Mountsmysql
#执行挂载命令-v ➜ ~ docker run -it -d --name centos01 -v /Users/dada/Downloads/docker-centos/etc:/etc centos 6080c9748915bd8c64d2cc218ff3f3431a155fd360be60620184eb80ba6a6add #查看运行中的容器列表 ➜ ~ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 6080c9748915 centos "/bin/bash" 3 seconds ago Up 2 seconds centos01 #进入容器 ➜ ~ docker exec -it 6080c9748915 /bin/bash #进入etc 建立文件并写入数据 bash-4.4# cd /etc/ bash-4.4# touch index.html & echo 'hi! smallForest'>index.html # ls一下 bash-4.4# ls hostname hosts index.html resolv.conf # 退出容器 bash-4.4# exit # 查看容器信息 inspect ➜ ~ docker inspect 6080c9748915 返回结果巨长,只写Mounts部分 "Mounts": [ { "Type": "bind", "Source": "/Users/dada/Downloads/docker-centos/etc", "Destination": "/etc", "Mode": "", "RW": true, "Propagation": "rprivate" } ], # 回到宿主机目录/Users/dada/Downloads/docker-centos/etc。校验index.html是否存在,内容是不是'hi! smallForest'
codenginx
# 查看运行中的容器 ➜ ~ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 6080c9748915 centos "/bin/bash" 12 minutes ago Up 12 minutes centos01 # 中止容器 ➜ ~ docker stop 6080c9748915 6080c9748915 ➜ ~ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES #在宿主机中修改index.html追加一句话 ➜ ~ vim /Users/dada/Downloads/docker-centos/etc/index.html ➜ ~ cat /Users/dada/Downloads/docker-centos/etc/index.html hi! smallForest update on MacOS #启动容器 ➜ ~ docker start 6080c9748915 6080c9748915 #进入容器 ➜ ~ docker exec -it 6080c9748915 /bin/bash #进入配置目录 bash-4.4# cd /etc/ #查看index.html已经同步更新 bash-4.4# cat index.html hi! smallForest update on MacOS
结论:容器中止宿主机修改文件重启后会同步sql
MySQL数据同步 持久化问题。须要配置pwddocker
docker run -d -p 3306:3306 -v /Users/dada/Downloads/docker-centos/mysql/conf:/etc/mysql/conf.d -v /Users/dada/Downloads/docker-centos/mysql/data:/var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 --name mysql01 mysql:5.7 Unable to find image 'mysql:5.7' locally 5.7: Pulling from library/mysql 69692152171a: Already exists 1651b0be3df3: Pull complete 951da7386bc8: Pull complete 0f86c95aa242: Pull complete 37ba2d8bd4fe: Pull complete 6d278bb05e94: Pull complete 497efbd93a3e: Pull complete a023ae82eef5: Pull complete e76c35f20ee7: Pull complete e887524d2ef9: Pull complete ccb65627e1c3: Pull complete Digest: sha256:a682e3c78fc5bd941e9db080b4796c75f69a28a8cad65677c23f7a9f18ba21fa Status: Downloaded newer image for mysql:5.7 bcc85b93643d2c1cb84f786eed080f55d346a8df15260327a673b8cd98224d14 # 使用密码123456链接Navicat 并建立一个数据库 # 删除容器 ➜ ~ docker stop bcc85b93643d & docker rm bcc85b93643d ➜ ~ docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES #回到宿主机目录/Users/dada/Downloads/docker-centos/mysql/data 查看数据库文件是否存在
结论:挂载到宿主机目录以后删除容器,数据不会删除数据库
-v 容器内目录!不指定宿主机路径json
codevim
# 启动NGINX容器,匿名挂载,-P表示自动指定端口 ➜ ~ docker run -d -P --name nginx01 -v /etc/nginx nginx:latest 8f2ea2ad93a0e3d98560c9f59e7d7f05a90375b909d7b265f14151e845256694 # 查看容器详情 ➜ ~ docker inspect 8f2ea2ad93a0 #简略展现 "Mounts": [ { "Type": "volume", "Name": "f50a729cba7814d70f11dbb0862c5aefc1b076b142c84bc5133986cdc2a869ce", "Source": "/var/lib/docker/volumes/f50a729cba7814d70f11dbb0862c5aefc1b076b142c84bc5133986cdc2a869ce/_data", "Destination": "/etc/nginx", "Driver": "local", "Mode": "", "RW": true, "Propagation": "" } ], # 查看本地全部卷的列表 ➜ ~ docker volume ls
给卷设置名字
-v 卷名:容器内目录centos
# 建立nginx容器 具名挂载 ➜ ~ docker run -d -P --name nginx03 -v juming-nginx:/etc/nginx nginx:latest cae84c37d3f4278815fd7793b59b54250dfc65355d9748d30dcebe6bf0e1de2e # 查看本地全部的卷 ➜ ~ docker volume ls DRIVER VOLUME NAME local juming-nginx local portainer_data local user_cert # 查看卷名“juming-nginx”的信息,Mountpoint就是宿主机存储文件位置 ➜ ~ docker volume inspect juming-nginx [ { "CreatedAt": "2021-05-26T09:10:55Z", "Driver": "local", "Labels": null, "Mountpoint": "/var/lib/docker/volumes/juming-nginx/_data", "Name": "juming-nginx", "Options": null, "Scope": "local" } ]
具名挂载方式方便找卷安全
扩展知识:
-v juming-nginx:/etc/nginx:ro
ro rw 分别表示只读 读写
ro表示挂载的路径只能在宿主机内修改,不能在容器内修改
code ==失败中==
➜ ~ docker run -d -P --name nginx05 -v /Users/dada/Downloads/docker-centos/nginx/conf:/etc/nginx:ro nginx:latest ➜ ~ docker inspect 容器id
初识Dockerfile
Dockerfile就是用来构建docker镜像的构建文件,命令脚本,经过脚本能够生成镜像。
# 打印当前路径 ➜ file pwd /Users/dada/Downloads/docker-centos/file # file路径下执行建立文件命令 ➜ file touch Dockerfile1 # 编辑文件写入内容 ➜ file vim Dockerfile1 # 查看是否写入成功 ➜ file cat Dockerfile1 FROM centos VOLUME ["volume01","volume02"] CMD echo "----end----" CMD /bin/bash # 命令行末尾缺乏点 报错 ➜ file docker build -f Dockerfile1 -t mycentos:02 "docker build" requires exactly 1 argument. See 'docker build --help'. Usage: docker build [OPTIONS] PATH | URL | - Build an image from a Dockerfile # 命令增长点 生成成功 ➜ file docker build -f Dockerfile1 -t mycentos:02 . [+] Building 0.1s (5/5) FINISHED => [internal] load build definition from Dockerfile1 0.0s => => transferring dockerfile: 123B 0.0s => [internal] load .dockerignore 0.0s => => transferring context: 2B 0.0s => [internal] load metadata for docker.io/library/centos:latest 0.0s => CACHED [1/1] FROM docker.io/library/centos 0.0s => exporting to image 0.0s => => exporting layers 0.0s => => writing image sha256:231feafd3348cc7cb6a2eeed8b19effe7b15fd2a723a287669e6d06 0.0s => => naming to docker.io/library/mycentos:02 0.0s Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them # 查看新建立镜像 ➜ file docker images|grep mycentos mycentos 02 231feafd3348 5 months ago 209MB ➜ file # 启动容器 ➜ file docker run -d -it --name mycentos02 mycentos:02 0ff56e3d5516174f39c9eb63bbced886d8470d963ef6dcf77ce67082226860b9 #查看容器列表 ➜ file docker ps|grep mycentos 0ff56e3d5516 mycentos:02 "/bin/sh -c /bin/bash" 37 seconds ago Up 36 seconds mycentos02 # inspect 查看容器数据卷挂载状况 ➜ file docker inspect 0ff56e3d5516 "Mounts": [ { "Type": "volume", "Name": "15a00b422c3ad4f7eac181566b51fc10d40e546b06a8d57100375aa58a0cc2b1", "Source": "/var/lib/docker/volumes/15a00b422c3ad4f7eac181566b51fc10d40e546b06a8d57100375aa58a0cc2b1/_data", "Destination": "volume02", "Driver": "local", "Mode": "", "RW": true, "Propagation": "" }, { "Type": "volume", "Name": "9e520b5a5872379b57c8ade61125cedfd6f0e180712ade07d25d2d8808ce5a0a", "Source": "/var/lib/docker/volumes/9e520b5a5872379b57c8ade61125cedfd6f0e180712ade07d25d2d8808ce5a0a/_data", "Destination": "volume01", "Driver": "local", "Mode": "", "RW": true, "Propagation": "" } ], ...... # 能够查看到volume01 volume02挂载成功
测试不加 -f 生成镜像
结论:在项目中Dockerfile文件的名字请使用“Dockerfile”,这是行业规范eg:composer.json go.mod等
➜ file ls Dockerfile1 ➜ file mv Dockerfile1 Dockerfile ➜ file docker build -t mycentos1:03 . [+] Building 0.1s (5/5) FINISHED => [internal] load build definition from Dockerfile 0.0s => => transferring dockerfile: 122B 0.0s => [internal] load .dockerignore 0.0s => => transferring context: 2B 0.0s => [internal] load metadata for docker.io/library/centos:latest 0.0s => CACHED [1/1] FROM docker.io/library/centos 0.0s => exporting to image 0.0s => => exporting layers 0.0s => => writing image sha256:231feafd3348cc7cb6a2eeed8b19effe7b15fd2a723a287669e6d06e35aa6261 0.0s => => naming to docker.io/library/mycentos1:03 0.0s Use 'docker scan' to run Snyk tests against images to find vulnerabilities and learn how to fix them ➜ file docker images|grep mycentos1 mycentos1 03 231feafd3348 5 months ago 209MB ➜ file
两个容器间数据同步,备份
举例:两个MySQL同步数据库数据
# 启动3个容器 # docker01 ➜ ~ docker run -d -it --name docker01 centos:latest 1a3e373b0d690d7f2c41577384e3a929d8c2067401d26eda2646e1547927952e ➜ ~ docker ps|grep docker0 1a3e373b0d69 centos:latest "/bin/bash" 55 seconds ago Up 54 seconds docker01 # docker02 docker01的数据会同步到docker02 ➜ ~ docker run -d -it --name docker02 --volumes-from docker01 centos:latest 297b7cbf22910888056b991abbb8e7ef141ed92b58ff60171025f7cb39cc27f1 #docker03 docker01的数据会同步到docker03 ➜ ~ docker run -d -it --name docker03 --volumes-from docker01 centos:latest 9c5366c63559aac7a78aa9eec0bd7933de4de475652780d9e6e1cd94a113838c #docker01 02 03会使用共同的数据卷 ➜ ~ docker ps|grep docker0 9c5366c63559 centos:latest "/bin/bash" 57 seconds ago Up 56 seconds docker03 297b7cbf2291 centos:latest "/bin/bash" About a minute ago Up About a minute docker02 1a3e373b0d69 centos:latest "/bin/bash" 5 minutes ago Up 5 minutes docker01 # 删除docker01对数据有什么影响吗? # 删除docker01对02 03没有影响,数据依旧在,备份机制
code
# mysql01 ➜ ~ docker run -d -p 3301:3306 -v /etc/mysql/conf.d -v /var/lib/mysql -e MYSQL_ROOT_PASSWORD=123456 --name mysql01 mysql:5.7 2e20d35d29b85d7474d7e6c873db800022dcbf1f0a5f2a2402309691f354672a ➜ ~ docker ps|grep mysql01 2e20d35d29b8 mysql:5.7 "docker-entrypoint.s…" 13 seconds ago Up 11 seconds 33060/tcp, 0.0.0.0:3301->3306/tcp, :::3301->3306/tcp mysql01 # mysql02 ➜ ~ docker run -d -p 3302:3306 -e MYSQL_ROOT_PASSWORD=123456 --name mysql02 --volumes-from mysql01 mysql:5.7 b6804fef3d73dd9648e35a18345d2dc654f6bf607f3aea1d274fe6d9edd720ba ➜ ~ docker ps|grep mysql02 b6804fef3d73 mysql:5.7 "docker-entrypoint.s…" 7 seconds ago Up 5 seconds 33060/tcp, 0.0.0.0:3302->3306/tcp, :::3302->3306/tcp mysql02 ➜ ~