[系统运维]普通用户执行docker命令用不用sudo由你决定

当我们用root身份在服务器部署docker后，如果想用普通用户操作docker应该如何做呢？

[root@shanghai-aliyun ~]# docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                                          NAMES
423435db3a3f        nginx               "/docker-entrypoint.…"   5 weeks ago         Up 3 weeks          0.0.0.0:180->80/tcp                                            nginx_nginx_1
9edbbba02a8b        fluentd_fluentd     "/bin/entrypoint.sh …"   5 weeks ago         Up 5 weeks          5140/tcp, 0.0.0.0:24224->24224/tcp, 0.0.0.0:24224->24224/udp   fluentd_fluentd_1
[root@shanghai-aliyun ~]# 
# 创建普通用户cntsp
[root@shanghai-aliyun ~]# useradd cntsp
# 给普通用户设置密码
[root@shanghai-aliyun ~]# passwd cntsp
# 切换普通用户身份
[root@shanghai-aliyun ~]# su cntsp
[cntsp@shanghai-aliyun ~]$ pwd
/home/cntsp
[cntsp@shanghai-aliyun ~]$ docker ps
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.39/containers/json: dial unix /var/run/docker.sock: connect: permission denied
# 上面说当尝试链接docker守护进程的socket时，获取权限被拒绝

# 下面我们在前面加上sudo命令
# Linux sudo命令以系统管理者的身份执行指令，也就是说，经由 sudo 所执行的指令就好像是 root 亲自执行
[cntsp@shanghai-aliyun ~]$ sudo docker ps

# 我们相信你已经从当地的系统管理员那里得到了通常的说教
# 通常可以归结为这三件事
We trust you have received the usual lecture from the local System
Administrator. It usually boils down to these three things:

    #1) Respect the privacy of others.
    #2) Think before you type.
    #3) With great power comes great responsibility.
    # 尊重他人隐私
    # 三思而后行
    # 权限越大责任越大

[sudo] password for cntsp: 
cntsp is not in the sudoers file.  This incident will be reported.
# cntsp 用户不在 sudoers 文件中，这一事件将被报道
# 貌似加上sudo, docker命令倒是可以执行了，但是没有正确返回，是因为该用户cntsp这时候又没有了sudo权限，根据命令行返回的提示，是因为普通用户cntsp不在/etc/sudoers文件中，那么我们就要好好摆姿摆子这个文件了

分析/etc/sudoers文件

[root@shanghai-aliyun ~]# ls -lh /etc/sudoers
-r--r-----. 1 root root 4.3K Nov 28  2019 /etc/sudoers
# 默认情况下是一个只读文件，并且其他人连读的权限也木有
[root@shanghai-aliyun ~]# cat /etc/sudoers
## Sudoers allows particular users to run various commands as
## the root user, without needing the root password.
#注释：sudoers 允许特别用户去作为root用户运行各种命令，而不需要root密码
##
## Examples are provided at the bottom of the file for collections
## of related commands, which can then be delegated out to particular
## users or groups.
# 注释：文件底部提供了相关命令集合的示例，这些命令可以被委托给特定的用户或者组
## 
## This file must be edited with the 'visudo' command.
# 这个文件必须被 visudo 命令编辑 # visudo -f /etc/sudoers

## Host Aliases
## Groups of machines. You may prefer to use hostnames (perhaps using 
## wildcards for entire domains) or IP addresses instead.
# Host_Alias     FILESERVERS = fs1, fs2
# Host_Alias     MAILSERVERS = smtp, smtp2

## User Aliases
## These aren't often necessary, as you can use regular groups
## (ie, from files, LDAP, NIS, etc) in this file - just use %groupname 
## rather than USERALIAS
# User_Alias ADMINS = jsmith, mikem


## Command Aliases
## These are groups of related commands...

## Networking
# Cmnd_Alias NETWORKING = /sbin/route, /sbin/ifconfig, /bin/ping, /sbin/dhclient, /usr/bin/net, /sbin/iptables, /usr/bin/rfcomm, /usr/bin/wvdial, /sbin/iwconfig, /sbin/mii-tool

## Installation and management of software
# Cmnd_Alias SOFTWARE = /bin/rpm, /usr/bin/up2date, /usr/bin/yum

## Services
# Cmnd_Alias SERVICES = /sbin/service, /sbin/chkconfig, /usr/bin/systemctl start, /usr/bin/systemctl stop, /usr/bin/systemctl reload, /usr/bin/systemctl restart, /usr/bin/systemctl status, /usr/bin/systemctl enable, /usr/bin/systemctl disable

## Updating the locate database
# Cmnd_Alias LOCATE = /usr/bin/updatedb

## Storage
# Cmnd_Alias STORAGE = /sbin/fdisk, /sbin/sfdisk, /sbin/parted, /sbin/partprobe, /bin/mount, /bin/umount

## Delegating permissions
# Cmnd_Alias DELEGATING = /usr/sbin/visudo, /bin/chown, /bin/chmod, /bin/chgrp 

## Processes
# Cmnd_Alias PROCESSES = /bin/nice, /bin/kill, /usr/bin/kill, /usr/bin/killall

## Drivers
# Cmnd_Alias DRIVERS = /sbin/modprobe

# Defaults specification

#
# Refuse to run if unable to disable echo on the tty.
#
Defaults   !visiblepw

#
# Preserving HOME has security implications since many programs
# use it when searching for configuration files. Note that HOME
# is already set when the the env_reset option is enabled, so
# this option is only effective for configurations where either
# env_reset is disabled or HOME is present in the env_keep list.
#
Defaults    always_set_home
Defaults    match_group_by_gid

# Prior to version 1.8.15, groups listed in sudoers that were not
# found in the system group database were passed to the group
# plugin, if any. Starting with 1.8.15, only groups of the form
# %:group are resolved via the group plugin by default.
# We enable always_query_group_plugin to restore old behavior.
# Disable this option for new behavior.
Defaults    always_query_group_plugin

Defaults    env_reset
Defaults    env_keep =  "COLORS DISPLAY HOSTNAME HISTSIZE KDEDIR LS_COLORS"
Defaults    env_keep += "MAIL PS1 PS2 QTDIR USERNAME LANG LC_ADDRESS LC_CTYPE"
Defaults    env_keep += "LC_COLLATE LC_IDENTIFICATION LC_MEASUREMENT LC_MESSAGES"
Defaults    env_keep += "LC_MONETARY LC_NAME LC_NUMERIC LC_PAPER LC_TELEPHONE"
Defaults    env_keep += "LC_TIME LC_ALL LANGUAGE LINGUAS _XKB_CHARSET XAUTHORITY"

#
# Adding HOME to env_keep may enable a user to run unrestricted
# commands via sudo.
#
# Defaults   env_keep += "HOME"

Defaults    secure_path = /sbin:/bin:/usr/sbin:/usr/bin

## Next comes the main part: which users can run what software on 
## which machines (the sudoers file can be shared between multiple
## systems).
## Syntax:
##
##      user    MACHINE=COMMANDS
##
## The COMMANDS section may have other options added to it.
##
## Allow root to run any commands anywhere 
root    ALL=(ALL)       ALL
# 上面root运行任何命令在任何地方
## Allows members of the 'sys' group to run networking, software, 
## service management apps and more.
# %sys ALL = NETWORKING, SOFTWARE, SERVICES, STORAGE, DELEGATING, PROCESSES, LOCATE, DRIVERS

## Allows people in group wheel to run all commands
%wheel  ALL=(ALL)       ALL
# 允许wheel组内的成员运行所有命令

## Same thing without a password
# %wheel        ALL=(ALL)       NOPASSWD: ALL
# 去掉注释就是允许wheel组内的成员运行所有命令而不需要密码
## Allows members of the users group to mount and unmount the 
## cdrom as root
# %users  ALL=/sbin/mount /mnt/cdrom, /sbin/umount /mnt/cdrom

## Allows members of the users group to shutdown this system
# %users  localhost=/sbin/shutdown -h now

## Read drop-in files from /etc/sudoers.d (the # here does not mean a comment)
#includedir /etc/sudoers.d

下面我们先把cntsp用户加入 wheel 组内，在执行 sudo docker ps 命令

[root@shanghai-aliyun ~]# id cntsp
uid=1003(cntsp) gid=1003(cntsp) groups=1003(cntsp)
[root@shanghai-aliyun ~]# gpasswd -a cntsp wheel
Adding user cntsp to group wheel
[root@shanghai-aliyun ~]# 
[root@shanghai-aliyun ~]# 
[root@shanghai-aliyun ~]# id cntsp
uid=1003(cntsp) gid=1003(cntsp) groups=1003(cntsp),10(wheel)
[root@shanghai-aliyun ~]# 
[root@shanghai-aliyun ~]# su cntsp
[cntsp@shanghai-aliyun root]$ 
[cntsp@shanghai-aliyun root]$ 
[cntsp@shanghai-aliyun root]$ pwd
/root
[cntsp@shanghai-aliyun root]$ cd
[cntsp@shanghai-aliyun ~]$ pwd
/home/cntsp
[cntsp@shanghai-aliyun ~]$ sudo docker ps
[sudo] password for cntsp:  # 这里需要输入cntsp用户的密码
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                                          NAMES
423435db3a3f        nginx               "/docker-entrypoint.…"   5 weeks ago         Up 3 weeks          0.0.0.0:180->80/tcp                                            nginx_nginx_1
9edbbba02a8b        fluentd_fluentd     "/bin/entrypoint.sh …"   5 weeks ago         Up 5 weeks          5140/tcp, 0.0.0.0:24224->24224/tcp, 0.0.0.0:24224->24224/udp   fluentd_fluentd_1

# 下面我们先切换 root身份 visudo 命令对 /etc/sudoers 文件进行编辑 
# 去掉注释 # %wheel        ALL=(ALL)       NOPASSWD: ALL

[root@shanghai-aliyun ~]# visudo -f /etc/sudoers
[root@shanghai-aliyun ~]# # 去掉注释后，我们切换cntsp 用户再次执行 sudo docker ps 命令
[root@shanghai-aliyun ~]# su cntsp
[cntsp@shanghai-aliyun root]$ whoami
cntsp
[cntsp@shanghai-aliyun root]$ sudo docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                                          NAMES
423435db3a3f        nginx               "/docker-entrypoint.…"   5 weeks ago         Up 3 weeks          0.0.0.0:180->80/tcp                                            nginx_nginx_1
9edbbba02a8b        fluentd_fluentd     "/bin/entrypoint.sh …"   5 weeks ago         Up 5 weeks          5140/tcp, 0.0.0.0:24224->24224/tcp, 0.0.0.0:24224->24224/udp   fluentd_fluentd_1
# 上面命令无需cntsp用户的密码即可执行显示
[cntsp@shanghai-aliyun root]$ docker ps
Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Get http://%2Fvar%2Frun%2Fdocker.sock/v1.39/containers/json: dial unix /var/run/docker.sock: connect: permission denied
# 尼玛，我懒，我漏输入sudo

不好意思，我特懒，我希望普通用户执行docker命令的时候，不要多敲这个sudo命令，想直接 docker ps 就给我正常返回,我们看到的是 /var/run/docker.sock 链接权限拒绝

[cntsp@shanghai-aliyun root]$ ls -lh /var/run/docker.sock
srw-rw---- 1 root docker 0 Jul 14 23:34 /var/run/docker.sock
# 我们把 cntsp 用户加入docker组,先查看有没有docker组
[root@shanghai-aliyun ~]# cat /etc/group |grep docker
dockerroot:x:993:
docker:x:992:
[root@shanghai-aliyun ~]# id cntsp
uid=1003(cntsp) gid=1003(cntsp) groups=1003(cntsp),10(wheel)
[root@shanghai-aliyun ~]# gpasswd -a cntsp docker
Adding user cntsp to group docker
[root@shanghai-aliyun ~]# id cntsp
uid=1003(cntsp) gid=1003(cntsp) groups=1003(cntsp),10(wheel),992(docker)
#  把用户cntsp加入docker组，同时保留原来所在组
# 再次切换为cntsp用户，执行 docker ps
[root@shanghai-aliyun ~]# su cntsp
[cntsp@shanghai-aliyun root]$ docker ps
CONTAINER ID        IMAGE               COMMAND                  CREATED             STATUS              PORTS                                                          NAMES
423435db3a3f        nginx               "/docker-entrypoint.…"   5 weeks ago         Up 3 weeks          0.0.0.0:180->80/tcp                                            nginx_nginx_1
9edbbba02a8b        fluentd_fluentd     "/bin/entrypoint.sh …"   5 weeks ago         Up 5 weeks          5140/tcp, 0.0.0.0:24224->24224/tcp, 0.0.0.0:24224->24224/udp   fluentd_fluentd_1
# 不用sudo命令，docker ps 正常返回了

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