docker镜像的实际使用学习
开发过程中，需要安装很多三方工具，比如etcd、kafka、mysql、nginx等等
1、下载安装Docker工具。
2、获取该软件的Docker镜像（基本上，都能搜索到核实的镜像），下载镜像nginx镜像，docker、pull nginx。
3、运行该镜像，启动一个容器，这个nginx服务就运行在容器中。
4、停止容器，删除该镜像，你的电脑，好像就没有使用nginx一样。
基于镜像的增删改查维护：
1、获取镜像
1、获取镜像，镜像托管仓库，好比yum源一样
默认的Docker仓库是：Dockerhub,有大量的优质镜像，以及用户自己上传的镜像CentOS容器
Docker search 镜像名：tag tag就是具体的标签版本
Dokcer search CentOS
注：1、查看docker是否启动，若有Client和Server就是启动的。
[root@Hadoop2 ~]# docker version
Client: Docker Engine - CommunityVersion: 24.0.6API version: 1.41 (downgraded from 1.43)Go version: go1.20.7Git commit: ed223bcBuilt: Mon Sep 4 12:35:25 2023OS/Arch: linux/amd64Context: defaultServer: Docker Engine - CommunityEngine:Version: 20.10.6API version: 1.41 (minimum version 1.12)Go version: go1.13.15Git commit: 8728dd2Built: Fri Apr 9 22:43:57 2021OS/Arch: linux/amd64Experimental: falsecontainerd:Version: 1.6.22GitCommit: 8165feabfdfe38c65b599c4993d227328c231fcarunc:Version: 1.1.8GitCommit: v1.1.8-0-g82f18fedocker-init:Version: 0.19.0GitCommit: de40ad0
2、查看当前运行中的容器
root@Hadoop2 ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
84544a09e63d nginx "/docker-entrypoint.…" 6 hours ago Up 6 hours 0.0.0.0:80->80/tcp, :::80->80/tcp gallant_goldberg3、查看本地的镜像文件有那些
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest f5a6b296b8a2 10 days ago 187MB
redis latest 39ac5829bade 11 days ago 138MB[root@Hadoop2 ~]# docker image ls
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest f5a6b296b8a2 10 days ago 187MB
redis latest 39ac5829bade 11 days ago 138MB4、下载镜像
#下载docker镜像
docker pull centos #默认的是centos:latest
docker pull centos:7.8.20035、查看镜像的储存路径
[root@Hadoop2 ~]# docker info
Client: Docker Engine - CommunityVersion: 24.0.6Context: defaultDebug Mode: falsePlugins:buildx: Docker Buildx (Docker Inc.)Version: v0.11.2Path: /usr/libexec/docker/cli-plugins/docker-buildxcompose: Docker Compose (Docker Inc.)Version: v2.21.0Path: /usr/libexec/docker/cli-plugins/docker-composeServer:Containers: 2Running: 1Paused: 0Stopped: 1Images: 2Server Version: 20.10.6Storage Driver: overlay2Backing Filesystem: xfsSupports d_type: trueNative Overlay Diff: trueuserxattr: falseLogging Driver: json-fileCgroup Driver: cgroupfsCgroup Version: 1Plugins:Volume: localNetwork: bridge host ipvlan macvlan null overlayLog: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslogSwarm: inactiveRuntimes: runc io.containerd.runc.v2 io.containerd.runtime.v1.linuxDefault Runtime: runcInit Binary: docker-initcontainerd version: 8165feabfdfe38c65b599c4993d227328c231fcarunc version: v1.1.8-0-g82f18feinit version: de40ad0Security Options:seccompProfile: defaultKernel Version: 3.10.0-1160.el7.x86_64Operating System: CentOS Linux 7 (Core)OSType: linuxArchitecture: x86_64CPUs: 8Total Memory: 3.84GiBName: Hadoop2ID: LNP5:33MY:CWU3:FMPD:EXRX:HZGK:KXM3:KHAH:CAGT:O4FV:DLXP:AGEPDocker Root Dir: /var/lib/dockerDebug Mode: falseExperimental: falseInsecure Registries:127.0.0.0/8Live Restore Enabled: false#目的地址[root@Hadoop2 ~]# docker info | grep RootDocker Root Dir: /var/lib/docker
6、查看存储的镜像
[root@Hadoop2 ~]# ls /var/lib/docker/image/overlay2/imagedb/content/sha256/
39ac5829badedab9c9d6915aefa8da387e423514c8c4680d8c4e0a67e2368a02 f5a6b296b8a29b4e3d89ffa99e4a86309874ae400e82b3d3993f84e1e3bb0eb9
[root@Hadoop2 ~]# ls /var/lib/docker/image/overlay2/imagedb/content/sha256/ -l
总用量 16
-rw------- 1 root root 7780 9月 14 14:27 39ac5829badedab9c9d6915aefa8da387e423514c8c4680d8c4e0a67e2368a02
-rw------- 1 root root 8147 9月 13 17:03 f5a6b296b8a29b4e3d89ffa99e4a86309874ae400e82b3d3993f84e1e3bb0eb9[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest f5a6b296b8a2 10 days ago 187MB
redis latest 39ac5829bade 11 days ago 138MB
注：变更加速源
7、删除镜像
#下载
docker pull hello-word#根据镜像的id、名称、摘要，被删除的镜像不得有容器记录
docker rmi hello-world#删除容器记录
[root@Hadoop2 ~]# docker rm 4cf129075bed
4cf129075bed#删除镜像成功
[root@Hadoop2 ~]# docker rmi hello-world:latest
Untagged: hello-world:latest
Untagged: hello-world@sha256:4f53e2564790c8e7856ec08e384732aa38dc43c52f02952483e3f003afbf23db
Deleted: sha256:9c7a54a9a43cca047013b82af109fe963fde787f63f9e016fdc3384500c2823d
Deleted: sha256:01bb4fce3eb1b56b05adf99504dafd31907a5aadac736e36b27595c8b92f07f1#删除镜像指定前三位即可
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
hello-world latest 9c7a54a9a43c 4 months ago 13.3kB
[root@Hadoop2 ~]# docker rmi 9c7
Untagged: hello-world:latest
Untagged: hello-world@sha256:4f53e2564790c8e7856ec08e384732aa38dc43c52f02952483e3f003afbf23db
Deleted: sha256:9c7a54a9a43cca047013b82af109fe963fde787f63f9e016fdc3384500c2823d
Deleted: sha256:01bb4fce3eb1b56b05adf99504dafd31907a5aadac736e36b27595c8b92f07f 注：删除容器记录。如果没有删除容器记录直接删减镜像会报错
注：正在运行的容器和所有容器
#正在运行的容器
[root@Hadoop2 ~]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES#所有容器
[root@Hadoop2 ~]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
84544a09e63d nginx "/docker-entrypoint.…" 5 days ago Exited (0) 4 days ago gallant_goldberg
00d67544a872 nginx "/docker-entrypoint.…" 9 days ago Exited (255) 9 days ago 0.0.0.0:80->80/tcp, :::80->80/tcp great_mayer
[root@Hadoop2 ~]#
镜像管理：
1、批量删除镜像
#查看列出本地镜像
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest f5a6b296b8a2 13 days ago 187MB
redis latest 39ac5829bade 2 weeks ago 138MB
centos latest 5d0da3dc9764 2 years ago 231MB#-a 列出本地所有镜像
[root@Hadoop2 ~]# docker images -a
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest f5a6b296b8a2 13 days ago 187MB
redis latest 39ac5829bade 2 weeks ago 138MB
centos latest 5d0da3dc9764 2 years ago 231MB#只显示镜像ID
[root@Hadoop2 ~]# docker images -aq
f5a6b296b8a2
39ac5829bade
5d0da3dc9764#echo打印反引号中语句执行的结果
[root@Hadoop2 ~]# echo `docker images -aq`
f5a6b296b8a2 39ac5829bade 5d0da3dc9764
[root@Hadoop2 ~]# #批量删除镜像、慎用
[root@Hadoop2 ~]# docker rmi `docker images -aq`
Untagged: redis:latest
Untagged: redis@sha256:f92a0be0ba8c085e6a5e2d2bea386365443485bcd67ced5ca8ddcdacdd4656d2
Deleted: sha256:39ac5829badedab9c9d6915aefa8da387e423514c8c4680d8c4e0a67e2368a02
Deleted: sha256:ca63b0754b94fce00f88849ca791a46d20036fdf833cec84fa828a7c5cb456e4
Deleted: sha256:701c3b8e81293857d87b169518f259edafe17e6b5e9f008f225bbe18fc55239c
Deleted: sha256:fc4c4559a037a9975d143450932206bd2ee760221a1d460fb0893611ac5dabbb
Deleted: sha256:d1bc31282da2e3624b875cb8626f45c54993aef0d4889a82616edbdd5fab012b
Deleted: sha256:3217de59d5a4ba6ec04f3b0296c7edadc6a3dd7a60a7cee3f6ae988d24f707c8
Untagged: centos:latest
Untagged: centos@sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
Deleted: sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6
Deleted: sha256:74ddd0ec08fa43d09f32636ba91a0a3053b02cb4627c35051aff89f853606b59
Error response from daemon: conflict: unable to delete f5a6b296b8a2 (must be forced) - image is being used by stopped container 00d67544a872
[root@Hadoop2 ~]# echo `docker images -aq`
f5a6b296b8a2
[root@Hadoop2 ~]#
2、导出镜像、导入镜像
#批量删除镜像的用法，rm
#批量删除镜像，慎用#批量删除容器
docker rm `docker ps -a`#1、比如默认运行的centos镜像，不提供vim功能，运行该容器后，在容器内安装vim
无vim
[root@Hadoop2 ~]# docker run -it centos bash
[root@81d951191d3d /]# vim
bash: vim: command not found
[root@81d951191d3d /]# 安装vim，若报错
[root@81d951191d3d /]# yum install vim -y
Failed to set locale, defaulting to C.UTF-8
CentOS Linux 8 - AppStream 53 B/s | 38 B 00:00
Error: Failed to download metadata for repo 'appstream': Cannot prepare internal mirrorlist: No URLs in mirrorlist
解决方法：https://developer.aliyun.com/article/1165954安装vim
[root@81d951191d3d yum.repos.d]# yum install vim -y检查是否安装好
[root@81d951191d3d yum.repos.d]# vim#2、提交该镜像，再导出该镜像为压缩文件，可以发给其他人用。但是我认为是提交的一个容器记录对应的容器，作为镜像，让后启动该镜像就是一个与生成容器记录的那个一样的容器。
#3、放在容器管理篇学习
docker commit#4、导出镜像的命令
导出镜像保存到指定位置，以压缩包形式存储
[root@Hadoop2 ~]# docker image save centos > /opt/centos
[root@Hadoop2 ~]# docker image save centos > /opt/centos.tgz
[root@Hadoop2 ~]# ls /opt/ -l
总用量 465984
-rw-r--r-- 1 root root 238581248 9月 23 13:23 centos
-rw-r--r-- 1 root root 238581248 9月 23 13:23 centos.tgz
drwx--x--x 4 root root 28 9月 12 21:08 containerd
drwxr-xr-x. 5 root root 55 6月 30 17:57 module
drwxr-xr-x. 2 root root 6 10月 31 2018 rh
drwxr-xr-x. 2 root root 108 6月 30 17:37 software
[root@Hadoop2 ~]# 导入镜像
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
<none> <none> b57d813f9e5d 41 minutes ago 559MB
nginx latest f5a6b296b8a2 2 weeks ago 187MB
[root@Hadoop2 ~]# docker image load -i /opt/centos.tgz
Loaded image: centos:latest
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
<none> <none> b57d813f9e5d 44 minutes ago 559MB
nginx latest f5a6b296b8a2 2 weeks ago 187MB
centos latest 5d0da3dc9764 2 years ago 231MB
[root@Hadoop2 ~]# 若删除镜像有依赖关系，可以通过镜像名+版本号删除
[root@Hadoop2 ~]# docker rmi 5d0da3dc9764
Error response from daemon: conflict: unable to delete 5d0da3dc9764 (cannot be forced) - image has dependent child images
[root@Hadoop2 ~]# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
<none> <none> b57d813f9e5d 39 minutes ago 559MB
nginx latest f5a6b296b8a2 2 weeks ago 187MB
centos latest 5d0da3dc9764 2 years ago 231MB通过镜像名+版本号删除
[root@Hadoop2 ~]# docker rmi centos:latest
Untagged: centos:latest
Untagged: centos@sha256:a27fd8080b517143cbbbab9dfb7c8571c40d67d534bbdee55bd6c473f432b177
[root@Hadoop2 ~]# 注：检验安装的vim
3、查看镜像的详细信息，语法：docker image inspect+镜像ID，列出的jeson信息；
[root@Hadoop2 ~]# docker image inspect 5d0da3dc9764
[{"Id": "sha256:5d0da3dc976460b72c77d94c8a1ad043720b0416bfc16c52c45d4847e53fadb6","RepoTags": ["centos:latest"],"RepoDigests": [],"Parent": "","Comment": "","Created": "2021-09-15T18:20:05.184694267Z","Container": "9bf8a9e2ddff4c0d76a587c40239679f29c863a967f23abf7a5babb6c2121bf1","ContainerConfig": {"Hostname": "9bf8a9e2ddff","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/sh","-c","#(nop) ","CMD [\"/bin/bash\"]"],"Image": "sha256:f5b050f177fd426be8fe998a8ecf3fb1858d7e26dff4080b29a327d1bd5ba422","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"}},"DockerVersion": "20.10.7","Author": "","Config": {"Hostname": "","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"],"Image": "sha256:f5b050f177fd426be8fe998a8ecf3fb1858d7e26dff4080b29a327d1bd5ba422","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"}},"Architecture": "amd64","Os": "linux","Size": 231268856,"VirtualSize": 231268856,"GraphDriver": {"Data": {"MergedDir": "/var/lib/docker/overlay2/6dddfccfb15dace43a872d1e3ff8826ddbf6e85a21069370284530793d41e55d/merged","UpperDir": "/var/lib/docker/overlay2/6dddfccfb15dace43a872d1e3ff8826ddbf6e85a21069370284530793d41e55d/diff","WorkDir": "/var/lib/docker/overlay2/6dddfccfb15dace43a872d1e3ff8826ddbf6e85a21069370284530793d41e55d/work"},"Name": "overlay2"},"RootFS": {"Type": "layers","Layers": ["sha256:74ddd0ec08fa43d09f32636ba91a0a3053b02cb4627c35051aff89f853606b59"]},"Metadata": {"LastTagTime": "0001-01-01T00:00:00Z"}}
]
[root@Hadoop2 ~]#
注：查看docker的进程的信息
查看docker进程的信息
[root@Hadoop2 ~]# docker info
Client: Docker Engine - CommunityVersion: 24.0.6Context: defaultDebug Mode: falsePlugins:buildx: Docker Buildx (Docker Inc.)Version: v0.11.2Path: /usr/libexec/docker/cli-plugins/docker-buildxcompose: Docker Compose (Docker Inc.)Version: v2.21.0Path: /usr/libexec/docker/cli-plugins/docker-composeServer:Containers: 0Running: 0Paused: 0Stopped: 0Images: 3Server Version: 20.10.6Storage Driver: overlay2Backing Filesystem: xfsSupports d_type: trueNative Overlay Diff: trueuserxattr: falseLogging Driver: json-fileCgroup Driver: cgroupfsCgroup Version: 1Plugins:Volume: localNetwork: bridge host ipvlan macvlan null overlayLog: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslogSwarm: inactiveRuntimes: io.containerd.runc.v2 io.containerd.runtime.v1.linux runcDefault Runtime: runcInit Binary: docker-initcontainerd version: 8165feabfdfe38c65b599c4993d227328c231fcarunc version: v1.1.8-0-g82f18feinit version: de40ad0Security Options:seccompProfile: defaultKernel Version: 3.10.0-1160.el7.x86_64Operating System: CentOS Linux 7 (Core)OSType: linuxArchitecture: x86_64CPUs: 8Total Memory: 3.84GiBName: Hadoop2ID: LNP5:33MY:CWU3:FMPD:EXRX:HZGK:KXM3:KHAH:CAGT:O4FV:DLXP:AGEPDocker Root Dir: /var/lib/dockerDebug Mode: falseExperimental: falseInsecure Registries:127.0.0.0/8Live Restore Enabled: false[root@Hadoop2 ~]# 
