Docker之docker镜像管理
作者：互联网
一 镜像结构和原理
1.1 Docker镜像原理
- 镜像即创建容器的模板，含有启动容器所需要的文件系统及所需要的内容，因此镜像主要用于方便和快速的创建并启动容器。
- Docker镜像采用分层构建机制，最底层为bootfs，其次为rootfs。
- bootfs用于系统引导的文件系统，包括bootloader和kernel，容器启动完成后会被卸载以节约内存资源。
- rootfs位于bootfs之上，表现为docker容器的根文件系统。在docker中rootfs由内核挂载为只读模式，而后通过联合挂载技术额外挂载一个可写层。
- 联合挂载技术可以将几层目录挂载到一起，形成一个虚拟文件系统。虚拟文件系统结构就像普通linux的目录结构一样。镜像通过这些文件再加上宿主机的内核共同提供了一个linux的虚拟环境，每一层文件系统叫做一层layer，联合文件系统可以对每一层文件系统系统设置三种权限，只读（readonly）、读写（readwrite）和写出（whiteout-able），但是镜像中每一层文件系统都是只读的。构建镜像的时候，从一个最基本的操作系统开始，每个构建提交的操作都相当于做一层的修改，增加了一层文件系统，一层层向上叠加，上层的修改会覆盖底层该位置的可见性，当使用镜像时，我们只会看到一个完整的整体，不知道里面有几层。
1.2 Docker镜像的结构
二 搜索镜像
点击查看代码
root@ubuntu:~# docker search nginx
NAME DESCRIPTION STARS OFFICIAL AUTOMATED
nginx Official build of Nginx. 15725 [OK]
jwilder/nginx-proxy Automated Nginx reverse proxy for docker con… 2088 [OK]
richarvey/nginx-php-fpm Container running Nginx + PHP-FPM capable of… 818 [OK]
jc21/nginx-proxy-manager Docker container for managing Nginx proxy ho… 266
linuxserver/nginx An Nginx container, brought to you by LinuxS… 159
tiangolo/nginx-rtmp Docker image with Nginx using the nginx-rtmp… 142 [OK]
jlesage/nginx-proxy-manager Docker container for Nginx Proxy Manager 142 [OK]
alfg/nginx-rtmp NGINX, nginx-rtmp-module and FFmpeg from sou… 110 [OK]
jasonrivers/nginx-rtmp Docker images to host RTMP streams using NGI… 95 [OK]
nginxdemos/hello NGINX webserver that serves a simple page co… 76 [OK]
privatebin/nginx-fpm-alpine PrivateBin running on an Nginx, php-fpm & Al… 59 [OK]
nginx/nginx-ingress NGINX and NGINX Plus Ingress Controllers fo… 55
nginxinc/nginx-unprivileged Unprivileged NGINX Dockerfiles 54
staticfloat/nginx-certbot Opinionated setup for automatic TLS certs lo… 25 [OK]
nginxproxy/nginx-proxy Automated Nginx reverse proxy for docker con… 23
nginx/nginx-prometheus-exporter NGINX Prometheus Exporter for NGINX and NGIN… 21
schmunk42/nginx-redirect A very simple container to redirect HTTP tra… 19 [OK]
centos/nginx-112-centos7 Platform for running nginx 1.12 or building … 15
centos/nginx-18-centos7 Platform for running nginx 1.8 or building n… 13
raulr/nginx-wordpress Nginx front-end for the official wordpress:f… 13 [OK]
flashspys/nginx-static Super Lightweight Nginx Image 11 [OK]
mailu/nginx Mailu nginx frontend 9 [OK]
sophos/nginx-vts-exporter Simple server that scrapes Nginx vts stats a… 7 [OK]
ansibleplaybookbundle/nginx-apb An APB to deploy NGINX 2 [OK]
wodby/nginx Generic nginx 1 [OK]三 下载镜像
root@ubuntu:~# docker pull 仓库服务器：端口/项目名称/镜像名称:tag
root@ubuntu:~# docker pull nginx四 查看本地镜像
root@ubuntu:~# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest 87a94228f133 2 weeks ago 133MB
hello-world latest feb5d9fea6a5 5 weeks ago 13.3kB五 镜像导出
root@ubuntu:~# docker save nginx -o /opt/nginx.tar.gz
root@ubuntu:~# ls -l /opt/nginx.tar.gz
-rw------- 1 root root 137544192 Oct 29 17:48 /opt/nginx.tar.gz六 镜像导入
root@ubuntu:~# docker load < /opt/nginx.tar.gz
e81bff2725db: Loading layer [==================================================>] 72.52MB/72.52MB
43f4e41372e4: Loading layer [==================================================>] 64.97MB/64.97MB
788e89a4d186: Loading layer [==================================================>] 3.072kB/3.072kB
f8e880dfc4ef: Loading layer [==================================================>] 4.096kB/4.096kB
f7e00b807643: Loading layer [==================================================>] 3.584kB/3.584kB
9959a332cf6e: Loading layer [==================================================>] 7.168kB/7.168kB
Loaded image: nginx:latest七 镜像重命名
root@ubuntu:~# docker tag nginx test_nginx:v1.0
root@ubuntu:~# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest 87a94228f133 2 weeks ago 133MB
test_nginx v1.0 87a94228f133 2 weeks ago 133MB
hello-world latest feb5d9fea6a5 5 weeks ago 13.3kB八 查看镜像分层历史
点击查看代码
root@ubuntu:~# docker image history nginx
IMAGE CREATED CREATED BY SIZE COMMENT
87a94228f133 2 weeks ago /bin/sh -c #(nop) CMD ["nginx" "-g" "daemon… 0B
<missing> 2 weeks ago /bin/sh -c #(nop) STOPSIGNAL SIGQUIT 0B
<missing> 2 weeks ago /bin/sh -c #(nop) EXPOSE 80 0B
<missing> 2 weeks ago /bin/sh -c #(nop) ENTRYPOINT ["/docker-entr… 0B
<missing> 2 weeks ago /bin/sh -c #(nop) COPY file:09a214a3e07c919a… 4.61kB
<missing> 2 weeks ago /bin/sh -c #(nop) COPY file:0fd5fca330dcd6a7… 1.04kB
<missing> 2 weeks ago /bin/sh -c #(nop) COPY file:0b866ff3fc1ef5b0… 1.96kB
<missing> 2 weeks ago /bin/sh -c #(nop) COPY file:65504f71f5855ca0… 1.2kB
<missing> 2 weeks ago /bin/sh -c set -x && addgroup --system -… 64MB
<missing> 2 weeks ago /bin/sh -c #(nop) ENV PKG_RELEASE=1~buster 0B
<missing> 2 weeks ago /bin/sh -c #(nop) ENV NJS_VERSION=0.6.2 0B
<missing> 2 weeks ago /bin/sh -c #(nop) ENV NGINX_VERSION=1.21.3 0B
<missing> 2 weeks ago /bin/sh -c #(nop) LABEL maintainer=NGINX Do… 0B
<missing> 2 weeks ago /bin/sh -c #(nop) CMD ["bash"] 0B
<missing> 2 weeks ago /bin/sh -c #(nop) ADD file:910392427fdf089bc… 69.3MB 九 查看镜像信息
点击查看代码
root@ubuntu:~# docker inspect nginx
[
{
"Id": "sha256:87a94228f133e2da99cb16d653cd1373c5b4e8689956386c1c12b60a20421a02",
"RepoTags": [
"nginx:latest",
"test_nginx:v1.0"
],
"RepoDigests": [],
"Parent": "",
"Comment": "",
"Created": "2021-10-12T02:03:40.360294686Z",
"Container": "21fd1c6cb532225ca7e04c77f6592e220574b919aec07021663576ef438e0fee",
"ContainerConfig": {
"Hostname": "21fd1c6cb532",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"80/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"NGINX_VERSION=1.21.3",
"NJS_VERSION=0.6.2",
"PKG_RELEASE=1~buster"
],
"Cmd": [
"/bin/sh",
"-c",
"#(nop) ",
"CMD [\"nginx\" \"-g\" \"daemon off;\"]"
],
"Image": "sha256:e30f1b92b2c67fbe72fb24af7353a945f6df4f48d9064d47bf0f51674311251e",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": [
"/docker-entrypoint.sh"
],
"OnBuild": null,
"Labels": {
"maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
},
"StopSignal": "SIGQUIT"
},
"DockerVersion": "20.10.7",
"Author": "",
"Config": {
"Hostname": "",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"80/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": [
"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
"NGINX_VERSION=1.21.3",
"NJS_VERSION=0.6.2",
"PKG_RELEASE=1~buster"
],
"Cmd": [
"nginx",
"-g",
"daemon off;"
],
"Image": "sha256:e30f1b92b2c67fbe72fb24af7353a945f6df4f48d9064d47bf0f51674311251e",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": [
"/docker-entrypoint.sh"
],
"OnBuild": null,
"Labels": {
"maintainer": "NGINX Docker Maintainers <docker-maint@nginx.com>"
},
"StopSignal": "SIGQUIT"
},
"Architecture": "amd64",
"Os": "linux",
"Size": 133277153,
"VirtualSize": 133277153,
"GraphDriver": {
"Data": {
"LowerDir": "/var/lib/docker/overlay2/5936365e35391fb0cbd58837deca3071b3e184f4b379ea9083fbe92abb41d1a1/diff:/var/lib/docker/overlay2/283e87848d1aa658db2042ef4a4e5e647df5802730c329055a2a9125a9af6048/diff:/var/lib/docker/overlay2/cc6da890b6136654f4d247b48a783d065bbed8c0bcf36515ab7fbd15273280c1/diff:/var/lib/docker/overlay2/fe9766053b8733da341d4c5d868f7ea156025820b62d1028174902f3d5696168/diff:/var/lib/docker/overlay2/ade8e887e82afa5c813e45352bec310a0120dc546ea7039b226c2d3877216207/diff",
"MergedDir": "/var/lib/docker/overlay2/272f7a79a4072689772c4344bc17bd165c91922aaa3bfc259a3411e87ba25499/merged",
"UpperDir": "/var/lib/docker/overlay2/272f7a79a4072689772c4344bc17bd165c91922aaa3bfc259a3411e87ba25499/diff",
"WorkDir": "/var/lib/docker/overlay2/272f7a79a4072689772c4344bc17bd165c91922aaa3bfc259a3411e87ba25499/work"
},
"Name": "overlay2"
},
"RootFS": {
"Type": "layers",
"Layers": [
"sha256:e81bff2725dbc0bf2003db10272fef362e882eb96353055778a66cda430cf81b",
"sha256:43f4e41372e42dd32309f6a7bdce03cf2d65b3ca34b1036be946d53c35b503ab",
"sha256:788e89a4d186f3614bfa74254524bc2e2c6de103698aeb1cb044f8e8339a90bd",
"sha256:f8e880dfc4ef19e78853c3f132166a4760a220c5ad15b9ee03b22da9c490ae3b",
"sha256:f7e00b807643e512b85ef8c9f5244667c337c314fa29572206c1b0f3ae7bf122",
"sha256:9959a332cf6e41253a9cd0c715fa74b01db1621b4d16f98f4155a2ed5365da4a"
]
},
"Metadata": {
"LastTagTime": "2021-10-29T17:54:04.494435623+08:00"
}
}
]十 删除镜像
点击查看代码
root@ubuntu:~# docker rmi nginx Untagged: nginx:latest Untagged: nginx@sha256:644a70516a26004c97d0d85c7fe1d0c3a67ea8ab7ddf4aff193d9f301670cf36 Deleted: sha256:87a94228f133e2da99cb16d653cd1373c5b4e8689956386c1c12b60a20421a02 Deleted: sha256:55b6972054b24c53054322a52748324df5797eefbb6dc374e41522a91d532dd5 Deleted: sha256:6b88aa6f4485486bfc779cccfbe4a7a47a502a7cff2cd70be89c59dcd0db12a8 Deleted: sha256:472c64059965c7b6b1b534ba07374c1d034b17c99acb3cf4534fe78abed41101 Deleted: sha256:788a5cf1e4599312b5923694f53e556ba0e2eb4a6bbb51958e0ec2b510345a49 Deleted: sha256:410f31f9ae37c62af85e8f9575c5f4d75542be1739ac1ca5982cf461be0b13bc Deleted: sha256:e81bff2725dbc0bf2003db10272fef362e882eb96353055778a66cda430cf81b
root@ubuntu:~# docker images
REPOSITORY TAG IMAGE ID CREATED SIZE
nginx latest 87a94228f133 2 weeks ago 133MB
hello-world latest feb5d9fea6a5 5 weeks ago 13.3kB
标签：bin,docker,ago,nginx,sh,镜像,Docker,weeks 来源： https://www.cnblogs.com/wangguishe/p/15481669.html