Docker自学笔记 (一)
Docker
文档
仓库
docker基本组成
镜像（image）
docker镜像是哟个模板，可以通过这个模板来创建容器服务
容器（container）
docker利用容器技术，独立运行一个或一个组应用，通过镜像来创建
启动、停止、删除
docker是个简易linux系统
仓库（repository）
仓库是放镜像的地方、
仓库分为公有仓库和私有仓库，docker hub 默认是国外的仓库
安装
环境查看
[root@localhost /]# cat /etc/redhat-release
CentOS Linux release 8.5.2111
[root@localhost /]# cat /etc/os-release
NAME="CentOS Linux"
VERSION="8"
ID="centos"
ID_LIKE="rhel fedora"
VERSION_ID="8"
PLATFORM_ID="platform:el8"
PRETTY_NAME="CentOS Linux 8"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:centos:centos:8"
HOME_URL="/"
BUG_REPORT_URL="/"
CENTOS_MANTISBT_PROJECT="CentOS-8"
CENTOS_MANTISBT_PROJECT_VERSION="8"
[root@localhost /]#
帮助文档
#1、卸载旧版本
yum remove docker \docker-client \docker-client-latest \docker-common \docker-latest \docker-latest-logrotate \docker-logrotate \docker-engine
#2、需要安装的包
sudo yum install -y yum-utils#3、设置镜像仓库
sudo yum-config-manager \--add-repo \.repo #阿里云推荐 \.repo #默认是国外的
#4、安装docker相关 docker-ce 社区 ee 企业版
yum install docker-ce docker-ce-cli containerd.io#5、启动daocker
systemctl start docker#6、使用docker version 检测安装
[root@localhost /]# docker version
Client: Docker Engine - CommunityVersion: 20.10.14API version: 1.41Go version: go1.16.15Git commit: a224086Built: Thu Mar 24 01:47:44 2022OS/Arch: linux/amd64Context: defaultExperimental: trueServer: Docker Engine - CommunityEngine:Version: 20.10.14API version: 1.41 (minimum version 1.12)Go version: go1.16.15Git commit: 87a90dcBuilt: Thu Mar 24 01:46:10 2022OS/Arch: linux/amd64Experimental: falsecontainerd:Version: 1.5.11GitCommit: 3df54a852345ae127d1fa3092b95168e4a88e2f8runc:Version: 1.0.3GitCommit: v1.0.3-0-gf46b6badocker-init:Version: 0.19.0GitCommit: de40ad0
[root@localhost /]##7、运行 hello worldsudo docker run hello-world
#8、查看下载hello world 的image
[root@localhost /]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker/getting-started latest bd9a9f733898 7 weeks ago 28.8MB
hello-world latest feb5d9fea6a5 6 months ago 13.3kB
#9、卸载
卸载依赖
yum remove docker-ce docker-ce-cli containerd.io
删除资源
rm -rf /var/lib/docker #默认工作路径
rm -rf /var/lib/containerd
阿里云镜像加速
(3条消息) docker配置阿里云镜像加速器_奕奕星空的博客-CSDN博客_云加速器
#报错 可以重启系统
底层原理
docker是怎么工作的？
Docker 是C/S结构系统，docker 的守护进程运行在主机上。通过Socket从客户端的访问，Server端接收到Docker-Client的指令，就回去执行这个命令。
Docker为什么比VM块？
1、Docker有着比虚拟机更少的抽象层。
2、docker 利用的是宿主机的内核。vm需要的guest os。
Docker常用命令
#文档
帮助命令
docker version #显示版本信息
docker info #显示docker的系统信息。包括镜像和容器数量
docker 命令 --help #帮助命令
镜像命令
docker images 查询本地镜像
docker images [OPTIONS] [REPOSITORY[:TAG]] #查看所有本地主机上的镜像[root@localhost /]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest feb5d9fea6a5 6 months ago 13.3kB
#解释
REPOSITORY 镜像的仓库源
TAG 镜像的标签
MAGE ID 镜像的ID
CREATED 镜像的创建时间
SIZE 镜像的大小#可选项Options:-a, --all #列出所有镜像-q, --quiet #只显示ID
docker search 搜索镜像
docker search [OPTIONS] TERM #搜索镜像#可选项，通过搜索来过滤--filter=STARS=3000
docker pull 下载镜像
docker pull 镜像名[:tag] #下载镜像[root@localhost docker]# docker pull centos
Using default tag: latest # 默认使用最新的
latest: Pulling from library/centos[root@localhost docker]# docker pull mysql:5.7
5.7: Pulling from library/mysql # 下载源
72a69066d2fe: Pull complete #分层下载
93619dbc5b36: Pull complete
99da31dd6142: Pull complete
626033c43d70: Pull complete
37d5d7efb64e: Pull complete
ac563158d721: Pull complete
d2ba16033dad: Pull complete
0ceb82207cd7: Pull complete
37f2405cae96: Pull complete
e2482e017e53: Pull complete
70deed891d42: Pull complete
Digest: sha256:f2ad209efe9c67104167fc609cca6973c8422939491c9345270175a300419f94 #签名
Status: Downloaded newer image for mysql:5.7
docker.io/library/mysql:5.7 #真实地址
#等价命令
docker pull mysql：5.7
docker pull docker.io/library/mysql:5.7Options:-a, --all-tags Download all tagged images in the repository--disable-content-trust Skip image verification (default true)--platform string Set platform if server is multi-platform capable-q, --quiet Suppress verbose output
[root@localhost /]#docker rmi 删除镜像
docker rmi [OPTIONS] IMAGE_ID IMAGE_ID ……-f, --force Force removal of the image--no-prune Do not delete untagged parents[root@localhost ~]# docker rmi -f feb5d9fea6a5 # 删除指定镜像[root@localhost ~]#docker rmi -f $(docker images -qa) #删除全部镜像
容器命令
说明:有镜像才可以创建容器
docker pull centos
新建容器并启动
docker run [可选参数] image_id
#参数说明
--name="Name" 容器名字 nginx1、nginx2
-d 后台运行方式
-it 使用交互方式运行，进入容器查看内容
-p 指定容器的端口 -p 8080:8080-o ip：主机端口：容器端口-p 主机端口：容器端口（常用）-p 容器端口容器端口
-p 随机端口#测试 启动并进入容器[root@localhost docker]# docker run -it centos /bin/bash
[root@84ead1d9d6e0 /]# ls #基础版本 很多命令不完善
bin dev etc home lib lib64 lost+found media mnt opt proc root run sbin
[root@84ead1d9d6e0 /]#exit #退出列出运行的容器
[root@localhost /]# docker ps # 列出当前运行的容器
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[root@localhost /]# docker ps -a # 列出历史运行的容器
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
84ead1d9d6e0 centos "/bin/bash" 2 minutes ago Exited (0) About a minute ago heuristic_rubin
[root@localhost /]# docker ps -n=1 #列出最近创建的容器
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
84ead1d9d6e0 centos "/bin/bash" 9 minutes ago Exited (0) 7 minutes ago heuristic_rubin
[root@localhost /]# docker ps -aq #只显示镜像ID
84ead1d9d6e0退出容器
exit #直接退出停止容器
Ctrl + P + Q #容器不停止退出
删除容器
docker rm 容器ID #删除指定容器
docker rm -f $(docker ps -aq) #删除所有容器
docker ps -aq | xargs docker rm
启动和停止
docker start 容器ID
docker restart 容器ID
docker stop 容器ID
docker kill 容器ID #强制停止容器常用的其他命令
后台启动命令
#命令 docker run -d images
[root@localhost /]# docker run -d centos
#问题docker ps ，发现 centos 停止了
#常见的坑：docker 容器使用后台云心，就必须有一个前台进程，docker 发现没有前台应用就会自动停止
#nginx 容器启动后 发现自己没有提供服务 就会立刻停止查看日志
docker logs -t -f --tail 容器ID#脚本
[root@localhost /]docker run -d centos /bin/bash -c "while true;do ping baidu;done"
[root@localhost /]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39b952d20d33 centos "/bin/bash -c 'while…" 12 minutes ago Up 12 minutes lucid_sanderson
#-tf 显示日志--tail 显示条数
[root@localhost /]docker logs -tf --tail 10 39b952d20d33
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查看容器的进程信息
#docker top 容器ID
[root@localhost /]# docker top 39b952d20d33
UID PID PPID C STIME TTY TIME CMD
root 38940 38920 0 02:21 ? 00:00:00 /bin/bash -c while true;do
root 38967 38940 0 02:21 ? 00:00:00 ping baidu
查看镜像的源数据
#命令
docker inspect 容器ID
[root@localhost ~]# docker inspect --helpUsage: docker inspect [OPTIONS] NAME|ID [NAME|ID...]Return low-level information on Docker objectsOptions:-f, --format string Format the output using the given Go template-s, --size Display total file sizes if the type is container--type string Return JSON for specified type[root@localhost ~]# docker inspect 39b952d20d33
[{"Id": "39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278","Created": "2022-04-05T18:21:04.893070851Z","Path": "/bin/bash","Args": ["-c","while true;do ping baidu;done"],"State": {"Status": "running","Running": true,"Paused": false,"Restarting": false,"OOMKilled": false,"Dead": false,"Pid": 38940,"ExitCode": 0,"Error": "","StartedAt": "2022-04-05T18:21:05.429467757Z","FinishedAt": "0001-01-01T00:00:00Z"},"Image": "sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6","ResolvConfPath": "/var/lib/docker/containers/39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278/resolv.conf","HostnamePath": "/var/lib/docker/containers/39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278/hostname","HostsPath": "/var/lib/docker/containers/39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278/hosts","LogPath": "/var/lib/docker/containers/39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278/39b952d20d33c9671a6fcad9748c1ee93c0b01cd6ac7b578baff1ecc76fda278-json.log","Name": "/lucid_sanderson","RestartCount": 0,"Driver": "overlay2","Platform": "linux","MountLabel": "","ProcessLabel": "","AppArmorProfile": "","ExecIDs": null,"HostConfig": {"Binds": null,"ContainerIDFile": "","LogConfig": {"Type": "json-file","Config": {}},"NetworkMode": "default","PortBindings": {},"RestartPolicy": {"Name": "no","MaximumRetryCount": 0},"AutoRemove": false,"VolumeDriver": "","VolumesFrom": null,"CapAdd": null,"CapDrop": null,"CgroupnsMode": "host","Dns": [],"DnsOptions": [],"DnsSearch": [],"ExtraHosts": null,"GroupAdd": null,"IpcMode": "private","Cgroup": "","Links": null,"OomScoreAdj": 0,"PidMode": "","Privileged": false,"PublishAllPorts": false,"ReadonlyRootfs": false,"SecurityOpt": null,"UTSMode": "","UsernsMode": "","ShmSize": 67108864,"Runtime": "runc","ConsoleSize": [0,0],"Isolation": "","CpuShares": 0,"Memory": 0,"NanoCpus": 0,"CgroupParent": "","BlkioWeight": 0,"BlkioWeightDevice": [],"BlkioDeviceReadBps": null,"BlkioDeviceWriteBps": null,"BlkioDeviceReadIOps": null,"BlkioDeviceWriteIOps": null,"CpuPeriod": 0,"CpuQuota": 0,"CpuRealtimePeriod": 0,"CpuRealtimeRuntime": 0,"CpusetCpus": "","CpusetMems": "","Devices": [],"DeviceCgroupRules": null,"DeviceRequests": null,"KernelMemory": 0,"KernelMemoryTCP": 0,"MemoryReservation": 0,"MemorySwap": 0,"MemorySwappiness": null,"OomKillDisable": false,"PidsLimit": null,"Ulimits": null,"CpuCount": 0,"CpuPercent": 0,"IOMaximumIOps": 0,"IOMaximumBandwidth": 0,"MaskedPaths": ["/proc/asound","/proc/acpi","/proc/kcore","/proc/keys","/proc/latency_stats","/proc/timer_list","/proc/timer_stats","/proc/sched_debug","/proc/scsi","/sys/firmware"],"ReadonlyPaths": ["/proc/bus","/proc/fs","/proc/irq","/proc/sys","/proc/sysrq-trigger"]},"GraphDriver": {"Data": {"LowerDir": "/var/lib/docker/overlay2/40a0f78a2b1de997b3f2af1897968b372fe6594c8236c33e091b8c5537c5c64b-init/diff:/var/lib/docker/overlay2/1fb6cbbaf813f00194bdb7ae04422e7aa31753a3ebe91d9f5f88fa54a04c2e16/diff","MergedDir": "/var/lib/docker/overlay2/40a0f78a2b1de997b3f2af1897968b372fe6594c8236c33e091b8c5537c5c64b/merged","UpperDir": "/var/lib/docker/overlay2/40a0f78a2b1de997b3f2af1897968b372fe6594c8236c33e091b8c5537c5c64b/diff","WorkDir": "/var/lib/docker/overlay2/40a0f78a2b1de997b3f2af1897968b372fe6594c8236c33e091b8c5537c5c64b/work"},"Name": "overlay2"},"Mounts": [],"Config": {"Hostname": "39b952d20d33","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"Tty": false,"OpenStdin": false,"StdinOnce": false,"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"],"Cmd": ["/bin/bash","-c","while true;do ping baidu;done"],"Image": "centos","Volumes": null,"WorkingDir": "","Entrypoint": null,"OnBuild": null,"Labels": {"org.label-schema.build-date": "20210915","org.label-schema.license": "GPLv2","org.label-schema.name": "CentOS Base Image","org.label-schema.schema-version": "1.0","org.label-schema.vendor": "CentOS"}},"NetworkSettings": {"Bridge": "","SandboxID": "f0f4e4d7c22cad51c1f6bbcc455a42ece6d208551c61587ac00c553d3e58a339","HairpinMode": false,"LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"Ports": {},"SandboxKey": "/var/run/docker/netns/f0f4e4d7c22c","SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"EndpointID": "0b799b7071838712d21071d6245983e02709a8d727f6577979ec0f230893b361","Gateway": "172.17.0.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","MacAddress": "02:42:ac:11:00:02","Networks": {"bridge": {"IPAMConfig": null,"Links": null,"Aliases": null,"NetworkID": "19eebba27026f51f10a5240fdcdc81de5f96d51abcf6035b543b3ce574d2c8c9","EndpointID": "0b799b7071838712d21071d6245983e02709a8d727f6577979ec0f230893b361","Gateway": "172.17.0.1","IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"MacAddress": "02:42:ac:11:00:02","DriverOpts": null}}}}
]进入当前运行的容器
#进入后台的运行的容器#命令
docker exec -it 39b952d20d33 bashShell
[root@localhost ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
39b952d20d33 centos "/bin/bash -c 'while…" About an hour ago Up About an hour [root@localhost ~]# docker exec -it 39b952d20d33 /bin/bash#docker attach 容器ID
#测试
[root@localhost ~]# docker attach 39b952d20d33
From 39b952d20d33 (172.17.0.2) icmp_seq=3680 Destination Host Unreachable#docker exec # 进入容器后开启一个终端
#docker attach #进入容器当前运行的终端
从容器拷贝文件到宿主机
docker cp 容器id：容器路径 #在容器内新建文件
[root@0372e62cc26f /]# touch dockercp.txt
[root@0372e62cc26f /]# ls
bin dockercp.txt home lib64 media opt root sbin sys usr
dev etc lib lost+found mnt proc run srv tmp var
[root@0372e62cc26f /]# docker cp 0372e62cc26f /dockercp.txt /root#将容器内的文件拷贝出来
[root@localhost ~]# docker cp 0372e62cc26f:/dockercp.txt /root
[root@localhost ~]# ls
anaconda-ks.cfg dockercp.txt ll test test1 testdir testdirln testln testln1
[root@localhost ~]#
小结
练习
安装nginx
在仓库搜索镜像
下载镜像
[root@localhost ~]# docker pull nginx
Using default tag: latest
latest: Pulling from library/nginx
a2abf6c4d29d: Pull complete
a9edb18cadd1: Pull complete
589b7251471a: Pull complete
186b1aaa4aa6: Pull complete
b4df32aa5a72: Pull complete
a0bcbecc962e: Pull complete
Digest: sha256:0d17b565c37bcbd895e9d92315a05c1c3c9a29f762b011a10c54a66cd53c9b31
Status: Downloaded newer image for nginx:latest
docker.io/library/nginx:latest
[root@localhost ~]#运行镜像
docker run -d --name nginx01 -p 3344:80 nginx
e1207663d7cecb3090bd35debcad2d47a5d0a54c1f6a2d441700ba2bba4135ec验证
[root@localhost ~]# curl localhost:3344
<!DOCTYPE html>
<html>
<head>
<title>Welcome to nginx!</title>
<style>
html { color-scheme: light dark; }
body { width: 35em; margin: 0 auto;
font-family: Tahoma, Verdana, Arial, sans-serif; }
</style>
</head>
<body>
<h1>Welcome to nginx!</h1>
<p>If you see this page, the nginx web server is successfully installed and
working. Further configuration is required.</p><p>For online documentation and support please refer to
<a href="/">nginx</a>.<br/>
Commercial support is available at
<a href="/">nginx</a>.</p><p><em>Thank you for using nginx.</em></p>
</body>
</html>进入容器
[root@localhost ~]# docker exec -it e1207663d7ce /bin/bash
root@e1207663d7ce:/#
安装tomcat
#官方使用docker run -it --rm tomcat:9.0#用完即删除#下载docker pull tomcat#启动运行
docker run -d -p 3355:8080 --name tomcat01 tomcat
#进入容器
[root@localhost ~]# docker exec -it tomcat01 /bin/bash
#linux 命令缺少 没有站点 #复制站点
root@139163325a5a:/usr/local/tomcat# cp -r webapps.dist/* webapps安装ES+kibana
#ES暴露端口多、占用资源多、数据单独挂载、docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" elasticsearch:8.1.2#启动之后 Linux 非常卡
docker stats#启动之后迅速关闭
docker stop e927e55d379c#验证
[root@localhost ~]# curl localhost:9200
{"name" : "fHjbm--","cluster_name" : "elasticsearch","cluster_uuid" : "kaCC5NXXTEKq87wd6TRJlQ","version" : {"number" : "5.6.12","build_hash" : "cfe3d9f","build_date" : "2018-09-10T20:12:43.732Z","build_snapshot" : false,"lucene_version" : "6.6.1"},"tagline" : "You Know, for Search"
}[root@localhost ~]# docker stats
CONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
e927e55d379c elasticsearch 0.11% 1.209GiB / 1.748GiB 69.17% 1.5kB / 729B 769MB / 49.2kB 39#-e 配置使用的内存
docker run -d --name elasticsearch -p 9200:9200 -p 9300:9300 -e "discovery.type=single-node" -e ES_JAVA_OPTS="-Xms64m -Xmx512M" elasticsearchCONTAINER ID NAME CPU % MEM USAGE / LIMIT MEM % NET I/O BLOCK I/O PIDS
2bac80f883af elasticsearch02 0.23% 244.1MiB / 1.748GiB 13.63% 766B / 0B 144MB / 67.6kB 36[root@localhost ~]# curl localhost:9200
{"name" : "ZS50Q_Z","cluster_name" : "elasticsearch","cluster_uuid" : "acXTAtDESFSxl2eA2ok1QA","version" : {"number" : "5.6.12","build_hash" : "cfe3d9f","build_date" : "2018-09-10T20:12:43.732Z","build_snapshot" : false,"lucene_version" : "6.6.1"},"tagline" : "You Know, for Search"
}
[root@localhost ~]#
ikbana如何连接docker
可视化
Install Portainer with Docker on Linux - Portainer Documentation 文档
#安装
docker run -d -p 8088:9000 --restart=always -v /var/run/docker.sock:/var/run/docker.sock --privileged=true portainer/portainer
http://192.168.0.16:8088/#/init/admin
Docker 镜像讲解
镜像是什么
是一种轻量级、可执行的独立软件包，用来打包软件运行环境和基于运行环境开发的软件，它包台运行某个软件所需的所有内容，包括代码、运行时、库、环变量和配置文件
所有的应用，直接打包docker镜像，就可以直接跑起来！
如何获得镜像
- 从远程仓库下载
- 朋友拷贝
- 自己制作一个镜像dockerfile
Docker镜像加载原理
UnionFS（联合文件系统〕
UnionFS（联合文件系统）：Union文件系统（UnionFS)是一种分层、轻量级并且高性能的文件系统，它支持对文件系统的修改作为一次提交来一层层的叠加，同时可以将不同目录挂载到同一个拟文件系统下（unite several directories into a single virtual filesystem)。Union文件系统是Docker镜像的基础。镜像可以通过分层来讲行继承，基于基础镜像（没有父像），可以制作各种具体的应用镜像。
特性：一次同时加载多个文件系统，但从外面看起来，只能看到一文件系统，联合加载会巴各层文件系统叠加起来，这样最终的文件系统会包含所有底层的文件和目录
Docker镜像加载原理
docker的镜像实际上由一层一层的文件系统组成，这种层级的文件系统UnionFS。
bootfs(bootfilesystem)主要包含bootloader和kernel,bootloaderæ要是引导Linux刚启动时会加载bootfs文件系
统，在Docker镜像的最底层是bootfso这一层与我们典型的Linux/Unix系统是一样的，包含boot加载器和内核。当boot加载完成之后整个内核就都在内存中了，此时内存的使用权已由bootfs转交给内核，此时系统也会卸载bootfs。
rootfs(rootfilesystem)，在bootfs之上。包含的就是典型Linux系统中的/dev,/proc,/bin,/etc等标准目录和文件。rootfs就是各种不同的操作系统发行版，比如Ubuntu，centos等等。
分层理解
[root@localhost ~]# docker pull redis
Using default tag: latest
latest: Pulling from library/redis
a2abf6c4d29d: Already exists
c7a4e4382001: Pull complete
4044b9ba67c9: Pull complete
c8388a79482f: Pull complete
413c8bb60be2: Pull complete
1abfd3011519: Pull complete
Digest: sha256:db485f2e245b5b3329fdc7eff4eb00f913e09d8feb9ca720788059fdc2ed8339
Status: Downloaded newer image for redis:latest
docker.io/library/redis:latest
[root@localhost ~]#
思考：为什么Docker镜像要采用这种分层的结构呢？
最大的好处，我觉得莫过于是资源共享了！比如有多个境像都从相同的Base源像构建而来，宿主机只需在磁盘上保留一份base像，同时内存中也只需要载一份b醑e像，这样就可以为所有的容器服务了，而目漳像的每一层都可以被共享。点看镜像分层的方式可以通过docker image inspect命令！
[root@localhost ~]# docker inspect redis:latest
[{"Id": "sha256:7614ae9453d1d87e740a2056257a6de7135c84037c367e1fffa92ae922784631","RepoTags": ["redis:latest"],"RepoDigests": ["redis@sha256:db485f2e245b5b3329fdc7eff4eb00f913e09d8feb9ca720788059fdc2ed8339"],"Parent": "","Comment": "","Created": "2021-12-21T12:42:49.755107412Z","Container": "13d25f53410417c5220c8dfe8bd49f06abdbcd69faa62a9b877de02464bb04a3","ContainerConfig": {"Hostname": "13d25f534104","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"ExposedPorts": {"6379/tcp": {}},"Tty": false,"OpenStdin": false,"StdinOnce": false,"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","GOSU_VERSION=1.12","REDIS_VERSION=6.2.6","REDIS_DOWNLOAD_URL=.2.6.tar.gz","REDIS_DOWNLOAD_SHA=5b2b8b7a50111ef395bf1c1d5be11e6e167ac018125055daa8b5c2317ae131ab"],"Cmd": ["/bin/sh","-c","#(nop) ","CMD [\"redis-server\"]"],"Image": "sha256:e093f59d716c95cfce82c676f099b960cc700432ab531388fcedf79932fc81ec","Volumes": {"/data": {}},"WorkingDir": "/data","Entrypoint": ["docker-entrypoint.sh"],"OnBuild": null,"Labels": {}},"DockerVersion": "20.10.7","Author": "","Config": {"Hostname": "","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"ExposedPorts": {"6379/tcp": {}},"Tty": false,"OpenStdin": false,"StdinOnce": false,"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin","GOSU_VERSION=1.12","REDIS_VERSION=6.2.6","REDIS_DOWNLOAD_URL=.2.6.tar.gz","REDIS_DOWNLOAD_SHA=5b2b8b7a50111ef395bf1c1d5be11e6e167ac018125055daa8b5c2317ae131ab"],"Cmd": ["redis-server"],"Image": "sha256:e093f59d716c95cfce82c676f099b960cc700432ab531388fcedf79932fc81ec","Volumes": {"/data": {}},"WorkingDir": "/data","Entrypoint": ["docker-entrypoint.sh"],"OnBuild": null,"Labels": null},"Architecture": "amd64","Os": "linux","Size": 112691373,"VirtualSize": 112691373,"GraphDriver": {"Data": {"LowerDir": "/var/lib/docker/overlay2/b94e3e76fe43e5b189d59382a1ca370bec538d1a0dea10e3b031a4bf9c4c57c1/diff:/var/lib/docker/overlay2/351c8e053f1467ef695036aefc82871a6bf3a9dc0c97b480aab6fdd06750f6ed/diff:/var/lib/docker/overlay2/ffe7db0d850a2c19799407fa06000e48e3856775840c21d427fbbc1688b8a4e7/diff:/var/lib/docker/overlay2/1aaf52a048a5b7731782f464e980d83ec1caa9010fc5289e572edab5ea00365b/diff:/var/lib/docker/overlay2/3a015bf48294c76365caf543e0470eede7d47c151551af6714519d2b282bb976/diff","MergedDir": "/var/lib/docker/overlay2/8e7f70fc7b48c75a391cd5887f4dbd61584ca25f8184de36a6385f0b1d96f1a9/merged","UpperDir": "/var/lib/docker/overlay2/8e7f70fc7b48c75a391cd5887f4dbd61584ca25f8184de36a6385f0b1d96f1a9/diff","WorkDir": "/var/lib/docker/overlay2/8e7f70fc7b48c75a391cd5887f4dbd61584ca25f8184de36a6385f0b1d96f1a9/work"},"Name": "overlay2"},"RootFS": {"Type": "layers","Layers": ["sha256:2edcec3590a4ec7f40cf0743c15d78fb39d8326bc029073b41ef9727da6c851f","sha256:9b24afeb7c2f21e50a686ead025823cd2c6e9730c013ca77ad5f115c079b57cb","sha256:4b8e2801e0f956a4220c32e2c8b0a590e6f9bd2420ec65453685246b82766ea1","sha256:529cdb636f61e95ab91a62a51526a84fd7314d6aab0d414040796150b4522372","sha256:9975392591f2777d6bf4d9919ad1b2c9afa12f9a9b4d260f45025ec3cc9b18ed","sha256:8e5669d8329116b8444b9bbb1663dda568ede12d3dbcce950199b582f6e94952"]},"Metadata": {"LastTagTime": "0001-01-01T00:00:00Z"}}
]
[root@localhost ~]#
特点
docker 镜像都是只读，当容器启动后，一个新的可写层被加载到镜像的顶部！
这一层就是我们通常说的容器层，容器层之下都叫镜像层。
如何提交一个自己的镜像？
Commit 镜像**
docker commit #提交容器成为一个副本
#命令和git原理类似
docker cimmit -m="提交描述信息" -a="作者" 容器ID 目标镜像名：[TAG]
练习
#启动一个默认的tomcat #默认的webapps 没有文件#拷贝文件#将修改后的容器通过commit 提交为一个镜像
[root@localhost ~]# docker commit -a="lxf" -m="add web app" 5b07255721fa tomcat02:1.0
sha256:aff84909b34e9948fa6c0ef61871d0e200a1b465176b82151953ca78376086ff
[root@localhost ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
tomcat02 1.0 aff84909b34e 11 seconds ago 684MB
nginx latest 605c77e624dd 3 months ago 141MB
tomcat 9.0 b8e65a4d736d 3 months ago 680MB
tomcat latest fb5657adc892 3 months ago 680MB
redis latest 7614ae9453d1 3 months ago 113MB
mysql 5.7 c20987f18b13 3 months ago 448MB
centos latest 5d0da3dc9764 6 months ago 231MB
portainer/portainer latest 580c0e4e98b0 12 months ago 79.1MB
elasticsearch latest 5acf0e8da90b 3 years ago 486MB
[root@localhost ~]#
docker commit -a="lxf" -m="add web app" 5b07255721fa tomcat02:1.0
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