config-docker-behind-proxy.md

Use docker behind proxy

When I run docker run hello-world, I get error message "docker: Error response from daemon: Get https://registry-1.docker.io/v2/: x509: certificate has expired or is not yet valid.". Here is the solution to this problem.

1. Create a systemd drop-in directory for the docker service:

   $ mkdir -p /etc/systemd/system/docker.service.d

2. Create a file called /etc/systemd/system/docker.service.d/http-proxy.conf that adds the HTTP_PROXY environment variable:

   [Service]
   Environment="HTTP_PROXY=http://proxy.example.com:80/"

3. If you have internal Docker registries that you need to contact without proxying you can specify them via the NO_PROXY environment variable:

   Environment="HTTP_PROXY=http://proxy.example.com:80/" "NO_PROXY=localhost,127.0.0.1,docker-registry.somecorporation.com"

4. Flush changes:

   $ sudo systemctl daemon-reload

5. Verify that the configuration has been loaded:

   $ systemctl show --property=Environment docker
   Environment=HTTP_PROXY=http://proxy.example.com:80/

6. Restart Docker:

   $ sudo systemctl restart docker