- `example.com` matches `example.com` and `foo.example.com`, and
     - `.example.com` matches only `foo.example.com`
   - A single asterisk (`*`) indicates that no proxying should be done
   - Literal port numbers are accepted by IP address prefixes (`1.2.3.4:80`) and
     domain names (`foo.example.com:80`)

   Example:

   ```systemd
   [Service]
   Environment="HTTP_PROXY=http://proxy.example.com:3128"
   Environment="HTTPS_PROXY=https://proxy.example.com:3129"
   Environment="NO_PROXY=localhost,127.0.0.1,docker-registry.example.com,.corp"
   ```

4. Flush changes and restart Docker

   ```console
   $ sudo systemctl daemon-reload
   $ sudo systemctl restart docker
   ```

5. Verify that the configuration has been loaded and matches the changes you
   made, for example:

   ```console
   $ sudo systemctl show --property=Environment docker

   Environment=HTTP_PROXY=http://proxy.example.com:3128 HTTPS_PROXY=https://proxy.example.com:3129 NO_PROXY=localhost,127.0.0.1,docker-registry.example.com,.corp
   ```

{{< /tab >}}
{{< tab name="Rootless mode" >}}

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

   ```console
   $ mkdir -p ~/.config/systemd/user/docker.service.d
   ```

2. Create a file named `~/.config/systemd/user/docker.service.d/http-proxy.conf`
   that adds the `HTTP_PROXY` environment variable:

   ```systemd
   [Service]
   Environment="HTTP_PROXY=http://proxy.example.com:3128"
   ```

   If you are behind an HTTPS proxy server, set the `HTTPS_PROXY` environment
   variable:

   ```systemd
   [Service]
   Environment="HTTPS_PROXY=https://proxy.example.com:3129"
   ```

   Multiple environment variables can be set; to set both a non-HTTPS and a
   HTTPs proxy;

   ```systemd
   [Service]
   Environment="HTTP_PROXY=http://proxy.example.com:3128"
   Environment="HTTPS_PROXY=https://proxy.example.com:3129"
   ```

   > [!NOTE]
   >
   > Special characters in the proxy value, such as `#?!()[]{}`, must be double
   > escaped using `%%`. For example:
   >
   > ```systemd
   > [Service]
   > Environment="HTTP_PROXY=http://domain%%5Cuser:complex%%23pass@proxy.example.com:3128/"
   > ```

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

   The `NO_PROXY` variable specifies a string that contains comma-separated
   values for hosts that should be excluded from proxying. These are the options
   you can specify to exclude hosts:

   - IP address prefix (`1.2.3.4`)
   - Domain name, or a special DNS label (`*`)
   - A domain name matches that name and all subdomains. A domain name with a
     leading "." matches subdomains only. For example, given the domains
     `foo.example.com` and `example.com`:
     - `example.com` matches `example.com` and `foo.example.com`, and
     - `.example.com` matches only `foo.example.com`
   - A single asterisk (`*`) indicates that no proxying should be done
   - Literal port numbers are accepted by IP address prefixes (`1.2.3.4:80`) and
     domain names (`foo.example.com:80`)

   Example:

   ```systemd
   [Service]
   Environment="HTTP_PROXY=http://proxy.example.com:3128"
   Environment="HTTPS_PROXY=https://proxy.example.com:3129"
   Environment="NO_PROXY=localhost,127.0.0.1,docker-registry.example.com,.corp"
   ```

4. Flush changes and restart Docker

   ```console
   $ systemctl --user daemon-reload
   $ systemctl --user restart docker
   ```

5. Verify that the configuration has been loaded and matches the changes you
   made, for example:

   ```console
   $ systemctl --user show --property=Environment docker

   Environment=HTTP_PROXY=http://proxy.example.com:3128 HTTPS_PROXY=https://proxy.example.com:3129 NO_PROXY=localhost,127.0.0.1,docker-registry.example.com,.corp
   ```

{{< /tab >}}
{{< /tabs >}}