在无根的环境中基本设置和使用podman
作者：互联网
在无根的环境中基本设置和使用podman
基本设置
cgroup V2Linux内核功能允许用户限制普通用户容器可以使用的资源，如果使用cgroupV2启用了运行Podman的Linux发行版，则可能需要更改默认的OCI运行时。某些较旧的版本runc不适用于cgroupV2，必须切换到备用OCI运行时crun。
[root@localhost ~]# dnf -y install crun
[root@localhost ~]# vim /usr/share/containers/containers.conf
runtime = "crun"
#runtime = "runc"
[root@localhost ~]# podman run -d --name web -p 80:80 httpd
7771b661a871d5e2e44080fc649400f2d45e650255bce3d2fea65dbf9ee4790c
[root@localhost ~]#
[root@localhost ~]# podman ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7771b661a871 docker.io/library/httpd:latest httpd-foreground 31 seconds ago Up 30 seconds ago 0.0.0.0:80->80/tcp web
[root@localhost ~]# podman inspect web | grep crun
"OCIRuntime": "crun",
"crun",
[root@localhost ~]#
安装slirp4netns和fuse-overlayfs
在普通用户环境中使用Podman时，建议使用fuse-overlayfs而不是VFS文件系统，至少需要版本0.7.6。下载slirp4netns和fuse-overlayfs
[root@localhost ~]# dnf -y install fuse-overlayfs
[root@localhost ~]# dnf -y install slirp4netns
[root@localhost ~]# vim /etc/containers/storage.conf
mount_program = "/usr/bin/fuse-overlayfs" #搜索fuse，取消这行注释
[root@localhost ~]# which fuse-overlayfs
/usr/bin/fuse-overlayfs
/etc/subuid和/etc/subgid配置
Podman要求运行它的用户在/ etc / subuid和/ etc / subgid文件中列出一系列UID,shadow-utils或newuid包提供这些文件
[root@localhost ~]# dnf -y install shadow-utils
在/etc/subuid和/etc/subgid查看，每个用户的值必须唯一且没有任何重叠。
[root@localhost ~]# useradd nie
[root@localhost ~]# cat /etc/subuid
nie:100000:65536
[root@localhost ~]# cat /etc/subgid
nie:100000:65536
[root@localhost ~]#
启动非特权ping
[root@localhost ~]# vim /etc/sysctl.conf
net.ipv4.ping_group_range=0 200000 #添加此行，大于100000这个就表示tom可以操作podman
这个文件的格式是 USERNAME:UID:RANGE中/etc/passwd或输出中列出的用户名getpwent。
- 为用户分配的初始 UID。
- 为用户分配的 UID 范围的大小。
该usermod程序可用于为用户分配 UID 和 GID，而不是直接更新文件。
[root@localhost ~]# useradd bang
[root@localhost ~]# cat /etc/subuid /etc/subgid
nie:100000:65536
bang:165536:65536
nie:100000:65536
bang:165536:65536
[root@localhost ~]#
[root@localhost ~]# cat /etc/subuid /etc/subgidnie:100000:65536
bang:165536:65536
bang:20000:101
nie:100000:65536
bang:165536:65536
bang:20000:101
[root@localhost ~]#
[root@localhost ~]# usermod --del-subuids 165536-231072 --del-subgids 165536-231072 bang
[root@localhost ~]# cat /etc/subuid /etc/subgid
nie:100000:65536
bang:20000:101
nie:100000:65536
bang:20000:101
[root@localhost ~]#
[root@localhost ~]# usermod --add-subuids 200000-201000 --add-subgids 200000-201000 bang
[root@localhost ~]# cat /etc/subuid /etc/subgid
nie:100000:65536
bang:20000:101
bang:200000:1001
nie:100000:65536
bang:20000:101
bang:200000:1001
[root@localhost ~]#
用户配置文件
三个主要的配置文件是container.conf、storage.conf和registries.conf。用户可以根据需要修改这些文件。
container.conf(容器配置文件)
// 用户配置文件
[root@localhost ~]# cat /usr/share/containers/containers.conf
[root@localhost ~]# cat /etc/containers/containers.conf
[root@localhost ~]# cat ~/.config/containers/containers.conf //优先级最高
storage.conf(存储配文件)
1./etc/containers/storage.conf
2.$HOME/.config/containers/storage.conf
在普通用户中/etc/containers/storage.conf的一些字段将被忽略
[root@localhost ~]# vim /etc/containers/storage.conf
driver = "overlay" #此处改为overlay
......
mount_program = "/usr/bin/fuse-overlayfs" #取消注释
[root@localhost ~]# vim /etc/sysctl.conf
user.max_user_namespaces=15000 #添加此行
在普通用户中这些字段默认
[root@podman ~]# vim /etc/containers/storage.conf
graphroot="$HOME/.local/share/containers/storage"
runroot="$XDG_RUNTIME_DIR/containers"
registries.conf(仓库配置文件)
配置按此顺序读入,这些文件不是默认创建的,可以从/usr/share/containers或复制文件/etc/containers并进行修改。
1./etc/containers/registries.conf
2./etc/containers/registries.d/*
3.HOME/.config/containers/registries.conf
授权文件
此文件里面写了docker账号的密码，以加密方式显示
root用户和普通用户的docker账号和密码授权是相同的
[root@localhost ~]# podman login
Username: daojiang
Password:
Login Succeeded!
[root@localhost ~]#
[root@localhost ~]# find / -name auth.json
/run/user/0/containers/auth.json
[root@localhost ~]#
[root@localhost ~]# cat /run/user/0/containers/auth.json
{
"auths": {
"docker.io": {
"auth": "ZGFvamlhbmc6MTIzNDU2Nzg5"
}
}
}[root@localhost ~]#
[nie@localhost ~]$ find / -name auth.json
/tmp/podman-run-1000/containers/auth.json
[nie@localhost ~]$
[nie@localhost ~]$ cat //tmp/podman-run-1000/containers/auth.json
{
"auths": {
"docker.io": {
"auth": "ZGFvamlhbmc6MTIzNDU2Nzg5"
}
}
}[nie@localhost ~]$
普通用户无法看见root用户的镜像和容器
[root@localhost ~]# podman images
REPOSITORY TAG IMAGE ID CREATED SIZE
docker.io/library/busybox latest beae173ccac6 7 months ago 1.46 MB
docker.io/library/httpd latest dabbfbe0c57b 7 months ago 148 MB
docker.io/library/alpine latest c059bfaa849c 8 months ago 5.87 MB
registry.fedoraproject.org/f29/httpd latest 25c76f9dcdb5 3 years ago 482 MB
[root@localhost ~]# podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
7771b661a871 docker.io/library/httpd:latest httpd-foreground 39 minutes ago Up 39 minutes ago 0.0.0.0:80->80/tcp web
[root@localhost ~]#
//普通用户
[root@localhost ~]# su - nie
Last login: Tue Aug 16 23:38:17 CST 2022 on pts/0
[nie@localhost ~]$ podman images
REPOSITORY TAG IMAGE ID CREATED SIZE
[nie@localhost ~]$ podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
[nie@localhost ~]$
//root用户也是无法看见普通用户的镜像和容器的
[nie@localhost ~]$ podman run -dit --name b2 -p 8080:80 httpd
fd4da7d86334d2a0d2c416764cedc45a78c92071a3f07ea79e37701adff6b9e9
[nie@localhost ~]$ podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd4da7d86334 docker.io/library/httpd:latest httpd-foreground 45 seconds ago Up 45 seconds ago 0.0.0.0:8080->80/tcp b2
[nie@localhost ~]$
//root用户
[root@localhost ~]# podman ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
- 容器与root用户一起运行，则root容器中的用户实际上就是主机上的用户。
[nie@localhost ~]$ podman ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
fd4da7d86334 docker.io/library/httpd:latest httpd-foreground 3 minutes ago Up 3 minutes ago 0.0.0.0:8080->80/tcp b2
[nie@localhost ~]$ podman exec -it b2 /bin/bash
root@fd4da7d86334:/usr/local/apache2# id
uid=0(root) gid=0(root) groups=0(root)
- UID GID是在/etc/subuid和/etc/subgid等中用户映射中指定的第一个UID GID。
- 如果普通用户的身份从主机目录挂载到容器中，并在该目录中以根用户身份创建文件，则会看到它实际上是你的用户在主机上拥有的。
使用卷
[nie@localhost ~]$ pwd
/home/nie
[nie@localhost ~]$ mkdir /home/nie/abc
#‘/abc:Z’默认是z指示绑定安装内容在多个容器直接共享，Z选项指示绑定安装内容是使用的且未共享
[nie@localhost ~]$ podman run -dit --name web1 -v /home/nie/abc/:/abc:Z -p 8080:80 httpd
c7ad45b2f663871eb3458812c7eef7889815e0b4178953a62d158a82ceed456f
[nie@localhost ~]$
[nie@localhost ~]$ podman exec -it web1 /bin/bash
root@c7ad45b2f663:/usr/local/apache2# cd /abc
root@c7ad45b2f663:/abc# touch 456
root@c7ad45b2f663:/abc# ls -l
total 0
-rw-r--r--. 1 root root 0 Aug 16 16:19 456
root@c7ad45b2f663:/abc#
//在主机上查看
[nie@localhost ~]$ ll abc/
total 0
-rw-r--r--. 1 nie nie 0 Aug 17 00:19 456
//在主机上写入文件
[nie@localhost ~]$
[nie@localhost ~]$ echo "hello world" >> abc/456
[nie@localhost ~]$ cat abc/456
hello world
[nie@localhost ~]$
容器里查看
[nie@localhost ~]$ podman exec -it web1 /bin/bash
root@c7ad45b2f663:/abc# cat 456
hello world
root@c7ad45b2f663:/abc#
root@c7ad45b2f663:/abc# ls -l
total 4
-rw-r--r--. 1 root root 12 Aug 16 16:21 456
root@c7ad45b2f663:/abc#
我们可以发现在容器里面的目录和文件的属主和属组都属于root，让其属于nie用户
//在运行容器的时候加上一个--userns=keep-id即可。保持一直id
[nie@localhost ~]$ podman rm -f -l
c7ad45b2f663871eb3458812c7eef7889815e0b4178953a62d158a82ceed456f
[nie@localhost ~]$ podman run -dit --name web1 --userns=keep-id -v $(pwd)/abc:/abc:Z busybox
Storing signatures
e7e46d4534e951a22fb77a71fa1167f0a09b1124121f258c604dbb7a7854504b
[nie@localhost ~]$
[nie@localhost ~]$ podman ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
e7e46d4534e9 docker.io/library/busybox:latest sh About a minute ago Up About a minute ago web1
[nie@localhost ~]$
使用普通用户映射容器端口时会报“ permission denied”的错误
[nie@localhost ~]$ podman run -dit --name no1 -p 80:80 httpd
Error: rootlessport cannot expose privileged port 80, you can add 'net.ipv4.ip_unprivileged_port_start=80' to /etc/sysctl.conf (currently 1024), or choose a larger port number (>= 1024): listen tcp 0.0.0.0:80: bind: permission denied
[nie@localhost ~]$
普通用户可以映射>= 1024的端口
#删除之前报错的容器后再创建
[nie@localhost ~]$ podman rm -f no1
d5ae497c96f97ef59d90322eee1b118a892999953430ffa18754664c859f3aa3
[nie@localhost ~]$ podman run -dit --name no1 -p 1024:80 httpd
56a77fa8c003e7209033a0c97bc541af2cb6107b2a6ab8c2e7ec6aeb26b42e73
[nie@localhost ~]$
[nie@localhost ~]$ ss -anlt
State Recv-Q Send-Q Local Address:Port Peer Address:Port Process
LISTEN 0 128 0.0.0.0:22 0.0.0.0:*
LISTEN 0 128 *:1024 *:*
LISTEN 0 128 [::]:22 [::]:*
[nie@localhost ~]$
配置echo ‘net.ipv4.ip_unprivileged_port_start=80’ >> /etc/sysctl.conf后可以映射大于等于80的端口
[root@localhost ~]# vim /etc/sysctl.conf
net.ipv4.ip_unprivileged_port_start=80 #添加此行
[root@localhost ~]# sysctl -p
net.ipv4.ping_group_range = 0 200000
user.max_user_namespaces = 15000
net.ipv4.ip_unprivileged_port_start = 80
[root@localhost ~]#
标签：etc,nie,podman,containers,设置,无根,root,localhost 来源： https://www.cnblogs.com/nie123/p/16593505.html