繼續學習入門知識。前面已經安裝了dokcer，如今來看看 docker image的相關命令nginx
[ec2-user@ip-172-16-1-4 ~]$ sudo docker image Usage: docker image COMMAND Manage images Commands: build Build an image from a Dockerfile history Show the history of an image import Import the contents from a tarball to create a filesystem image inspect Display detailed information on one or more images load Load an image from a tar archive or STDIN ls List images prune Remove unused images pull Pull an image or a repository from a registry push Push an image or a repository to a registry rm Remove one or more images save Save one or more images to a tar archive (streamed to STDOUT by default) tag Create a tag TARGET_IMAGE that refers to SOURCE_IMAGE
下面按順序簡單的過一遍docker
build是建立鏡像，這個後面會有具體介紹bash
history 能夠看見鏡像的歷史。docker的鏡像是一個多層的結構，好比說，這個裏面的結構其實都是咱們在建立docker鏡像到時候輸入的命令tcp
127MB [ec2-user@ip-172-16-1-4 ~]$ sudo docker image history nginx IMAGE CREATED CREATED BY SIZE COMMENT 8cf1bfb43ff5 2 days ago /bin/sh -c #(nop) CMD ["nginx" "-g" "da emon… 0B <missing> 2 days ago /bin/sh -c #(nop) STOPSIGNAL SIGTERM 0B <missing> 2 days ago /bin/sh -c #(nop) EXPOSE 80 0B <missing> 2 days ago /bin/sh -c #(nop) ENTRYPOINT ["/docker- entr… 0B <missing> 2 days ago /bin/sh -c #(nop) COPY file:0fd5fca330dc d6a7… 1.04kB <missing> 2 days ago /bin/sh -c #(nop) COPY file:1d0a4127e78a 26c1… 1.96kB <missing> 2 days ago /bin/sh -c #(nop) COPY file:e7e183879c35 719c… 1.2kB <missing> 2 days ago /bin/sh -c set -x && addgroup --syst em -… 63.3MB <missing> 2 days ago /bin/sh -c #(nop) ENV PKG_RELEASE=1~bus ter 0B <missing> 2 days ago /bin/sh -c #(nop) ENV NJS_VERSION=0.4.2 0B <missing> 2 days ago /bin/sh -c #(nop) ENV NGINX_VERSION=1.1 9.1 0B <missing> 2 days ago /bin/sh -c #(nop) LABEL maintainer=NGIN X Do… 0B <missing> 2 days ago /bin/sh -c #(nop) CMD ["bash"] 0B <missing> 2 days ago /bin/sh -c #(nop) ADD file:6ccb3bbcc69b0 d44c… 69.2MB
import 是從一個tar文件裏面導入容器的文件系統來生成一個鏡像，對應的咱們能夠從docker container的命令裏面export一個容器的文件系統到一個tar文件裏面。ide
inspect 是一個通用的命令， 主要是顯示一些常見docker對象的信息學習
[root@ip-172-16-1-4 ec2-user]# docker inspect --help
Usage: docker inspect [OPTIONS] NAME|ID [NAME|ID...]
Return low-level information on Docker objects
Options:
-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
好比 我查看一下nginx這個鏡像的信息ui
root@ip-172-16-1-4 ec2-user]# docker inspect nginx
[
{
"Id": "sha256:8cf1bfb43ff5d9b05af9b6b63983440f137c6a08320fa7592197c1474ef30241",
"RepoTags": [
"nginx:latest"
],
"RepoDigests": [
"nginx@sha256:0e188877aa60537d1a1c6484b8c3929cfe09988145327ee47e8e91ddf6f76f5c"
],
"Parent": "",
"Comment": "",
"Created": "2020-07-22T03:23:26.691138735Z",
"Container": "072f077fe42b39ffb92ca368fa5d79be975faa97b33bffb5b5383eb6abfb4838",
"ContainerConfig": {
"Hostname": "072f077fe42b",
"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=1.19.1",
"NJS_VERSION=0.4.2",
"PKG_RELEASE=1~buster"
],
"Cmd": [
"/bin/sh",
ls 就是顯示當前有哪些鏡像spa
[root@ip-172-16-1-4 ec2-user]# docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE nginx latest 8cf1bfb43ff5 2 days ago 132MB nginx 1.17 9beeba249f3e 2 months ago 127MB
save 和load 相對應，一個是把鏡像和相關的資源打包到一個tar文件裏面，一個是把這些資源再加載回來。他們的使用場景能夠用於備份，或者把鏡像拷貝到其餘地方使用。3d
[root@ip-172-16-1-4 ec2-user]# docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE nginx latest 8cf1bfb43ff5 2 days ago 132MB nginx 1.17 9beeba249f3e 2 months ago 127MB [root@ip-172-16-1-4 ec2-user]# docker image save 8cf1bfb43ff5 > nginx.tar [root@ip-172-16-1-4 ec2-user]# du nginx.tar -h 131M nginx.tar
生成以後，我來嘗試刪除一下現有的鏡像，他會提示報錯，由於我有個容器關聯着這個鏡像code
[root@ip-172-16-1-4 ec2-user]# docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE nginx latest 8cf1bfb43ff5 2 days ago 132MB nginx 1.17 9beeba249f3e 2 months ago 127MB [root@ip-172-16-1-4 ec2-user]# docker ps CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 34eef288fd4b nginx "/docker-entrypoint.…" 23 hours ago Up 23 hours 0.0.0.0:8080->80/tcp focused_grothendieck [root@ip-172-16-1-4 ec2-user]# docker image rm 8cf1bfb43ff5 Error response from daemon: conflict: unable to delete 8cf1bfb43ff5 (cannot be forced) - image is being used by running container 34eef288fd4b [root@ip-172-16-1-4 ec2-user]#
強制關掉正在運行的容器
[root@ip-172-16-1-4 ec2-user]# docker stop $(docker ps -a -q) 34eef288fd4b
如今就能夠刪除鏡像了
[root@ip-172-16-1-4 ec2-user]# docker image rm 8cf1bfb43ff5 Error response from daemon: conflict: unable to delete 8cf1bfb43ff5 (must be forced) - image is being used by stopped container 34eef288fd4b [root@ip-172-16-1-4 ec2-user]# docker image rm 8cf1bfb43ff5 -f Untagged: nginx:latest Untagged: nginx@sha256:0e188877aa60537d1a1c6484b8c3929cfe09988145327ee47e8e91ddf6f76f5c Deleted: sha256:8cf1bfb43ff5d9b05af9b6b63983440f137c6a08320fa7592197c1474ef30241 [root@ip-172-16-1-4 ec2-user]# docker image ls REPOSITORY TAG IMAGE ID CREATED SIZE nginx 1.17 9beeba249f3e 2 months ago 127MB
pull 和 push 相對，一個是下載鏡像，一個是上傳鏡像。當咱們直接調用 docker run的時候，他會嘗試從本地找對應的鏡像來建立容器，若是本地沒有，那麼會自動下載。固然咱們也能夠 用 pull先下載以後，在建立容器。
[root@ip-172-16-1-4 ec2-user]# docker image pull nginx Using default tag: latest latest: Pulling from library/nginx 6ec8c9369e08: Already exists d3cb09a117e5: Already exists 7ef2f1459687: Already exists e4d1bf8c9482: Already exists 795301d236d7: Already exists Digest: sha256:0e188877aa60537d1a1c6484b8c3929cfe09988145327ee47e8e91ddf6f76f5c Status: Downloaded newer image for nginx:latest docker.io/library/nginx:latest
prune
這個單詞的本意是修剪枝葉，他的做用也差很少。 有的時候，鏡像可能會出現問題，致使名字變成none，這樣的鏡像是有問題的，prune能夠直接刪掉。有的時候，鏡像沒有鏈接到任何容器，爲了節約空間，咱們也能夠把這些鏡像自動批量刪掉。
[root@ip-172-16-1-4 ec2-user]# docker image prune -a WARNING! This will remove all images without at least one container associated to them. Are you sure you want to continue? [y/N] y Deleted Images: untagged: nginx:1.17 untagged: nginx@sha256:6fff55753e3b34e36e24e37039ee9eae1fe38a6420d8ae16ef37c92d1eb26699 deleted: sha256:9beeba249f3ee158d3e495a6ac25c5667ae2de8a43ac2a8bfd2bf687a58c06c9 deleted: sha256:8fb6373b4cca3383756d7fd7843dd92f95827e5f2913609e09a9621dcddb3752 deleted: sha256:8b09841626797a03a9fe5e73aa38aeacf9ff0ce85a3004236ff35234eec3b35c deleted: sha256:ffc9b21953f4cd7956cdf532a5db04ff0a2daa7475ad796f1bad58cfbaf77a07 Total reclaimed space: 126.8MB