Podman基础 – 源码巴士

文章目录

1.Podman基础

1、什么是Podman？
Podman是一种开源的Linux原生工具，旨在根据开放容器倡议(Open Container Initiative，OCI)标准
开发、管理和运行容器和Pod。Podman是RedHat开发的一个用户友好的容器调度器，是RedHat 8和
CentOS 8中默认的容器引擎。
它是一款集合了命令集的工具，设计初衷是为了处理容器化进程的不同任务，可以作为一个模块化框架
工作。它的工具集包括：

Podman：Pod和容器镜像管理器
Buildah：容器镜像生成器
Skopeo：容器镜像检查管理器
Runc：容器运行器和特性构建器，并传递给Podman和Buildah
Crun：可选运行时，为Rootless容器提供更大的灵活性、控制和安全性

2、Podman和Docker的区别

docker需要使用root用户来创建容器，但是podman不需要，这点很友好
docker启动的容器支持 --restart 策略，但是 podman不支持，如果在k8s中就不存在这个问题，可以设置pod的重启策略，在系统中我们可以采用编写systemd服务来完成自启动
启动容器的方式不同：

docker 需要在我们的系统上运行一个守护进程(docker daemon)，而 podman 不需要

docker cli 命令通过API跟 Docker Engine(引擎)交互告诉它我想创建一个container(容器)，
然后docker Engine才会调用OCI container runtime(runc)来启动一个container。这代表
container的process(进程)不会是Docker CLI的child process(子进程)，而是Docker
Engine(引擎)的child process(子进程)。
Podman是直接给OCI containner runtime(runc)进行交互来创建容器的，所以
container(容器) process(进程)直接是podman的child process(子进程)。

请添加图片描述

图中所体现的事情是，podman不需要守护进程，而dorker需要守护进程。在这个图的示意中，
dorcker的containerd-shim与podman的common被归在Container一层。

##Podman的使用

3.Podman的安装

安装yum仓库

[root@localhost ~]# cd /etc/yum.repos.d/
[root@localhost yum.repos.d]# ls
CentOS-Base.repo
[root@localhost yum.repos.d]# curl -o /etc/yum.repos.d/CentOS-Base.repo https://mirrors.aliyun.com/repo/Centos-vault-8.5.2111.repo
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
100  2495  100  2495    0     0   3904      0 --:--:-- --:--:-- --:--:--  3898
[root@localhost yum.repos.d]# sed -i -e '/mirrors.cloud.aliyuncs.com/d' -e '/mirrors.aliyuncs.com/d' /etc/yum.repos.d/CentOS-Base.repo

安装podman

[root@localhost ~]# yum -y install podman
[root@localhost ~]# podman version
Version:      3.3.1
API Version:  3.3.1
Go Version:   go1.16.7
Built:        Wed Nov 10 05:23:56 2021
OS/Arch:      linux/amd64

配置加速器

这里使用的是阿里云加速器，获取方法见Docker基础用法
备份配置文件

[root@localhost ~]# cd /etc/containers/
[root@localhost containers]# ls
certs.d  oci  policy.json  registries.conf  registries.conf.d  registries.d  storage.conf
[root@localhost containers]# mv registries.conf registries.conf.backups

新建一个空的registries.conf文件，并进行配置

[root@localhost containers]# vim registries.conf

unqualified-search-registries = ["docker.io"]
  
[[registry]]
prefix = ""
location= "78r4hj7b.mirror.aliyuncs.com"

4.Podman常用命令

镜像
podman search #查找镜像

[root@localhost ~]# podman search httpd
INDEX       NAME                                             DESCRIPTION                                      STARS       OFFICIAL    AUTOMATED
docker.io   docker.io/library/httpd                          The Apache HTTP Server Project                   4116        [OK]        
docker.io   docker.io/clearlinux/httpd                       httpd HyperText Transfer Protocol (HTTP) ser...  2                       
docker.io   docker.io/centos/httpd-24-centos7                Platform for running Apache httpd 2.4 or bui...  44                      
docker.io   docker.io/manageiq/httpd                         Container with httpd, built on CentOS for Ma...  1                       [OK]
docker.io   docker.io/centos/httpd-24-centos8                                                                 1                       
docker.io   docker.io/dockerpinata/httpd                            
......

podman pull #获取镜像

[root@localhost ~]# podman pull busybox
Resolved "busybox" as an alias (/etc/containers/registries.conf.d/000-shortnames.conf)
Trying to pull docker.io/library/busybox:latest...
Getting image source signatures
Copying blob 50783e0dfb64 done  
Copying config 7a80323521 done  
Writing manifest to image destination
Storing signatures
7a80323521ccd4c2b4b423fa6e38e5cea156600f40cd855e464cc52a321a24dd

podman images #列出镜像

[root@localhost ~]# podman images
REPOSITORY                 TAG         IMAGE ID      CREATED      SIZE
docker.io/library/busybox  latest      7a80323521cc  2 weeks ago  1.47 MB

podman rmi #删除镜像

[root@localhost ~]# podman rmi busybox
Untagged: docker.io/library/busybox:latest
Deleted: 7a80323521ccd4c2b4b423fa6e38e5cea156600f40cd855e464cc52a321a24dd
[root@localhost ~]# podman images
REPOSITORY  TAG         IMAGE ID    CREATED     SIZE

podman inspect 获取镜像的详细信息

[root@localhost ~]# docker inspect 镜像名:标签
.....

podman tag 添加镜像别名，类似于别名

[root@localhost ~]# docker tag 镜像名:标签 新镜像名:新标签```
[root@localhost ~]# podman tag busybox:latest lxy:v1
[root@localhost ~]# podman images
REPOSITORY                 TAG         IMAGE ID      CREATED      SIZE
docker.io/library/busybox  latest      7a80323521cc  2 weeks ago  1.47 MB
localhost/lxy              v1          7a80323521cc  2 weeks ago  1.47 MB

podman save #导出镜像

[root@localhost ~]# podman  save > busybox.tar busybox
[root@localhost ~]# ls
anaconda-ks.cfg  busybox.tar

podman load #导入镜像

[root@localhost ~]# podman  load < busybox.tar 
Getting image source signatures
Copying blob 084326605ab6 skipped: already exists  
Copying config 7a80323521 done  
Writing manifest to image destination
Storing signatures
Loaded image(s): docker.io/library/busybox:latest
[root@localhost ~]# podman images
REPOSITORY                 TAG         IMAGE ID      CREATED      SIZE
docker.io/library/busybox  latest      7a80323521cc  2 weeks ago  1.47 MB

容器
podman run #创建并启动容器

[root@localhost ~]# podman run -dit --name a1 httpd
6cd221e9b957318108adb350fb3fb5f9039546cba7f11281872e8cd0e444350d

podman create #创建容器

[root@localhost ~]# podman create httpd

podman ps # 查看容器

[root@localhost ~]# podman ps
CONTAINER ID  IMAGE                             COMMAND     CREATED             STATUS                 PORTS       NAMES
6cd221e9b957  docker.io/lanmeishashou/httpd:v2  sh          About a minute ago  Up About a minute ago              a1

podman start # 启动容器

[root@localhost ~]# podman start 6cd221
6cd221
[root@localhost ~]# podman ps
CONTAINER ID  IMAGE                             COMMAND     CREATED        STATUS             PORTS       NAMES
6cd221e9b957  docker.io/lanmeishashou/httpd:v2  sh          5 minutes ago  Up 22 seconds ago              a1

podman stop # 停止容器

[root@localhost ~]# podman stop a1
a1
[root@localhost ~]# podman ps 
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES

podman restart # 重启容器

[root@localhost ~]# podman  restart a1
6cd221e9b957318108adb350fb3fb5f9039546cba7f11281872e8cd0e444350d

podman rm # 删除容器

[root@localhost ~]# podman ps -a
CONTAINER ID  IMAGE                             COMMAND     CREATED         STATUS            PORTS       NAMES
6cd221e9b957  docker.io/lanmeishashou/httpd:v2  sh          13 minutes ago  Up 5 minutes ago              a1
[root@localhost ~]# podman  rm -f a1
6cd221e9b957318108adb350fb3fb5f9039546cba7f11281872e8cd0e444350d
[root@localhost ~]# podman ps -a
CONTAINER ID  IMAGE       COMMAND     CREATED     STATUS      PORTS       NAMES

podman attach # 进入容器

[root@localhost ~]# podman attach a1
/ # ls
bin   data  dev   etc   home  proc  root  run   sys   tmp   usr   var

podman exec # 进入容器

[root@localhost ~]# podman exec -it a2 /bin/sh
/ # ls
bin   data  dev   etc   home  proc  root  run   sys   tmp   usr   var

podman export # 导出容器

[root@localhost ~]# podman  export -o a1.tar a1
[root@localhost ~]# ls
a1.tar  anaconda-ks.cfg  busybox.tar

podman import # 导入容器快照

[root@localhost ~]# podman  import a1.tar 
Getting image source signatures
Copying blob b012d45ecfc6 done  
Copying config 48b85c216c done  
Writing manifest to image destination
Storing signatures
sha256:48b85c216c841d85365d263cf9fa02388e534db0bc1f6882f6f2adad6849cd65
[root@localhost ~]# podman images
REPOSITORY                     TAG         IMAGE ID      CREATED             SIZE
<none>                         <none>      48b85c216c84  About a minute ago  1.47 MB
docker.io/lanmeishashou/httpd  v2          6b5cc1e1770f  6 days ago          1.47 MB
docker.io/library/busybox      latest      7a80323521cc  2 weeks ago         1.47 MB
localhost/lxy                  v1          7a80323521cc  2 weeks ago         1.47 MB

###Podman镜像的拉取与推送
设置镜像别名，名称为lanmeishashou/runtime，版本为v2

[root@localhost ~]# podman tag docker.io/library/busybox:latest docker.io/lanmeibingsha/runtime:v2
[root@localhost ~]# podman images
REPOSITORY                       TAG         IMAGE ID      CREATED        SIZE
<none>                           <none>      48b85c216c84  7 minutes ago  1.47 MB
docker.io/lanmeishashou/httpd    v2          6b5cc1e1770f  6 days ago     1.47 MB
docker.io/library/busybox        latest      7a80323521cc  2 weeks ago    1.47 MB
localhost/lxy                    v1          7a80323521cc  2 weeks ago    1.47 MB
docker.io/lanmeibingsha/runtime  v2          7a80323521cc  2 weeks ago    1.47 MB

登陆我们dockerhub账号

[root@localhost ~]# podman login
Username: lanmeishashou
Password: 
Login Succeeded!

上传刚才修改的镜像

[root@localhost ~]# podman push docker.io/lanmeishashou/aa:v5
Getting image source signatures
Copying blob 084326605ab6 skipped: already exists  
Copying config 7a80323521 done  
Writing manifest to image destination
Storing signatures

请添加图片描述

从网上下载我们刚上传的镜像

[root@localhost ~]# podman pull lanmeishashou/aa:v5
Resolving "lanmeishashou/aa" using unqualified-search registries (/etc/containers/registries.conf)
Trying to pull docker.io/lanmeishashou/aa:v5...
Getting image source signatures
Copying blob 50783e0dfb64 [--------------------------------------] 0.0b / 0.0b
Copying config 7a80323521 done  
Writing manifest to image destination
Storing signatures
7a80323521ccd4c2b4b423fa6e38e5cea156600f40cd855e464cc52a321a24dd
[root@localhost ~]# podman images
REPOSITORY                       TAG         IMAGE ID      CREATED            SIZE
<none>                           <none>      48b85c216c84  About an hour ago  1.47 MB
docker.io/lanmeishashou/httpd    v2          6b5cc1e1770f  6 days ago         1.47 MB
docker.io/library/busybox        latest      7a80323521cc  2 weeks ago        1.47 MB
localhost/lxy                    v1          7a80323521cc  2 weeks ago        1.47 MB
docker.io/lanmeibingsha/runtime  v2          7a80323521cc  2 weeks ago        1.47 MB
docker.io/lanmeibingsha/hhh      v8          7a80323521cc  2 weeks ago        1.47 MB
docker.io/lanmeishashou/aa       v5          7a80323521cc  2 weeks ago        1.47 MB

原文链接：https://blog.csdn.net/m0_71618402/article/details/126352623