Docker守护进程绑定到Unix套接字，而不是TCP端口。 默认情况下，Unix套接字由root用户拥有，其他用户只能使用sudo访问它。Docker守护进程始终以根用户运行。

如果不想在docker命令前面加上sudo，可以创建一个名为docker的Unix组，并向其中添加用户。当Docker守护进程启动时，它会创建一个Unix套接字，供Docker组的成员访问。

创建docker组并添加用户:

Create the docker group sudo groupadd docker Add your user to the docker group sudo usermod -aG docker $USER Log out and log back in so that your group membership is re-evaluated. If testing on a virtual machine, it may be necessary to restart the virtual machine for changes to take effect. On a desktop Linux environment such as X Windows, log out of your session completely and then log back in. On Linux, you can also run the following command to activate the changes to groups: newgrp docker Verify that you can run docker commands without sudo. The below command downloads a test image and runs it in a container. When the container runs, it prints an informational message and exits docker run hello-world

如果您在将用户添加到Docker组之前首先使用sudo运行Docker CLI命令，您可能会看到以下错误，这表明您的~/。由于sudo命令，创建的Docker /目录权限不正确。

   WARNING: Error loading config file: /home/user/.docker/config.json -
   stat /home/user/.docker/config.json: permission denied

要解决这个问题，要么删除~/。Docker /目录(它会自动重新创建，但任何自定义设置都将丢失)，或使用以下命令更改其所有权和权限:

sudo chown "$USER":"$USER" /home/"$USER"/.docker -R

sudo chmod g+rwx "$HOME/.docker" -R

linux上docker的所有其他后期安装步骤都可以在这里找到https://docs.docker.com/engine/install/linux-postinstall/

使用这个命令

sudo usermod -aG docker $USER

然后重新启动你的电脑这对我有用。

我用命令解决了这个错误:

$ sudo chmod 666 /var/run/docker.sock

Ubuntu 21.04 systemd套接字所有权

让我先说明一下，这是一个非常适合我在本地开发期间的解决方案，我在这里搜索ubuntu docker权限错误，所以我就把这个留在这里。

unix套接字不是我的，所以我学会了。

sudo chown $(whoami):$(whoami) /var/run/docker.sock

对于您的开发环境，另一个更持久的解决方案是修改unix套接字创建的用户所有权。这将给你的用户所有权，所以它将在重启之间坚持:

sudo nano /etc/systemd/system/sockets.target.wants/docker.socket

docker.socket:

[Unit]
Description=Docker Socket for the API

[Socket]
ListenStream=/var/run/docker.sock
SocketMode=0660
SocketUser=YOUR_USERNAME_HERE
SocketGroup=docker

[Install]
WantedBy=sockets.target

在Centos上安装Docker后。在运行下面的命令时，我得到下面的错误。

[centos@aiops-dev-cassandra3 ~]$ docker run hello-world
docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.soc k/v1.40/containers/create: dial unix /var/run/docker.sock: connect: permission denied.
See 'docker run --help'.

修改docker.socket的Group和Permission

[centos@aiops-dev-cassandra3 ~]$ ls -l /lib/systemd/system/docker.socket
-rw-r--r--. 1 root root 197 Nov 13 07:25 /lib/systemd/system/docker.socket
[centos@aiops-dev-cassandra3 ~]$ sudo chgrp docker /lib/systemd/system/docker.socket
[centos@aiops-dev-cassandra3 ~]$ sudo chmod 666 /var/run/docker.sock
[centos@aiops-dev-cassandra3 ~]$ ls -lrth /var/run/docker.sock
srw-rw-rw-. 1 root docker 0 Nov 20 11:59 /var/run/docker.sock
[centos@aiops-dev-cassandra3 ~]$

使用以下docker命令进行验证

[centos@aiops-dev-cassandra3 ~]$ docker run hello-world
Unable to find image 'hello-world:latest' locally
latest: Pulling from library/hello-world
1b930d010525: Pull complete
Digest: sha256:c3b4ada4687bbaa170745b3e4dd8ac3f194ca95b2d0518b417fb47e5879d9b5f
Status: Downloaded newer image for hello-world:latest

Hello from Docker!
This message shows that your installation appears to be working correctly.

To generate this message, Docker took the following steps:
 1. The Docker client contacted the Docker daemon.
 2. The Docker daemon pulled the "hello-world" image from the Docker Hub.
    (amd64)
 3. The Docker daemon created a new container from that image which runs the
    executable that produces the output you are currently reading.
 4. The Docker daemon streamed that output to the Docker client, which sent it
    to your terminal.

To try something more ambitious, you can run an Ubuntu container with:
 $ docker run -it ubuntu bash

Share images, automate workflows, and more with a free Docker ID:
 https://hub.docker.com/

For more examples and ideas, visit:
 https://docs.docker.com/get-started/

[centos@aiops-dev-cassandra3 ~]$

认真的人。不要在你的组中添加Docker或修改套接字posix(没有加固SELinux)，这是一个简单的方法来创建一个根privesc。只要在你的。bashrc中添加一个别名，这样更简单更安全:alias dc='sudo docker'。