In some cases, we need to pull some docker image through our custom proxy server.
But the HTTPS_PROXY and HTTP_PROXY in current login terminal will not be useful for the docker pull command.
The proxychains-ng tool is the same situation.
This is because docker is divided into dockerd and client. The docker pull command is executed by dockerd service. So we need make sure dockerd use proxy server.
The Docker daemon uses the HTTP_PROXY, HTTPS_PROXY, and NO_PROXY environmental variables in its start-up environment to configure HTTP or HTTPS proxy behavior. You cannot configure these environment variables using the daemon.json file.
So we can edit the systemd service file.
1.First create a new folder
$ sudo mkdir -p /etc/systemd/system/docker.service.d
2.Then create a new file named /etc/systemd/system/docker.service.d/http-proxy.conf
[Service]
Environment="HTTP_PROXY=http://proxy.example.com:80"
Environment="HTTPS_PROXY=http://proxy.example.com:80"
3.Reload and restart
$ sudo systemctl daemon-reload
$ sudo systemctl restart docker
4.Verify that the configuration has been loaded and matches the changes you made, for example:
$ sudo systemctl show --property=Environment docker