How to set proxy for Docker in Ubuntu?

What you will read?

1 Step 1: Identify Your Proxy Server
2 Step 2: Configure Docker to Use the Proxy
3 Step 3: Testing Your Proxy Configuration

Configuring Docker to use a proxy server is essential in environments where direct internet access is restricted or when you need to route traffic through a specific proxy. In this guide, we will walk you through the steps to set up a proxy for Docker on an Ubuntu system.

Step 1: Identify Your Proxy Server

Before configuring Docker, you need the details of your proxy server, including the IP address and port number. The proxy format typically looks like this:

http://username:[email protected]:port

If your proxy does not require authentication, it will look like:

http://proxyserver.com:port

Step 2: Configure Docker to Use the Proxy

In this step, we will configure Docker to route its network traffic through a specified proxy server. This is essential for environments where direct internet access is not available, or to enforce network policies. There are two primary methods to achieve this:

Method 1: Set Proxy in Docker Service Configuration

Create or Edit the Systemd Drop-in File:

Docker uses systemd to manage its service. You can create a drop-in file to set the proxy settings. Open a terminal and create a directory for the Docker service configuration if it doesn’t exist:

Create/Edit the Configuration File:

Create or edit the http-proxy.conf file:

sudo nano /etc/systemd/system/docker.service.d/http-proxy.conf

Add the following lines, replacing the placeholders with your actual proxy details:

[Service]
Environment="HTTP_PROXY=http://username:[email protected]:port/"
Environment="HTTPS_PROXY=http://username:[email protected]:port/"
Environment="NO_PROXY=localhost,127.0.0.1"

If your proxy does not require authentication, you can simplify it:

[Service]
Environment="HTTP_PROXY=http://proxyserver.com:port/"
Environment="HTTPS_PROXY=http://proxyserver.com:port/"
Environment="NO_PROXY=localhost,127.0.0.1"

Reload Systemd Configuration:

After saving the changes, reload the systemd configuration to apply the changes:
```
sudo systemctl daemon-reload
```
Restart Docker Service:

Restart the Docker service to apply the new proxy settings:
```
sudo systemctl restart docker
```

Method 2: Configure Proxy in Docker Daemon Configuration File

Alternatively, you can configure the proxy settings directly in the Docker daemon configuration file.

Edit the Docker Daemon Configuration File:

Open or create the daemon.json file:
```
sudo nano /etc/docker/daemon.json
```

Add Proxy Settings:

Add the following JSON configuration, replacing the placeholders as necessary:

{
  "proxies": {
    "default": {
      "httpProxy": "http://username:[email protected]:port/",
      "httpsProxy": "http://username:[email protected]:port/",
      "noProxy": "localhost,127.0.0.1"
    }
  }
}

If your proxy does not require authentication, it will look like this:

{
  "proxies": {
    "default": {
      "httpProxy": "http://proxyserver.com:port/",
      "httpsProxy": "http://proxyserver.com:port/",
      "noProxy": "localhost,127.0.0.1"
    }
  }
}

Restart Docker Service:
Save the changes and restart the Docker service:
```
sudo systemctl restart docker
```

Step 3: Testing Your Proxy Configuration

To verify that Docker is using the proxy settings, you can pull an image from Docker Hub. Run:

docker run hello-world

If the image pulls successfully, your proxy configuration is working correctly.

By following these steps, you have successfully configured Docker to use a proxy in Ubuntu. This setup is crucial for managing containerized applications in restricted network environments. For more tips and tutorials, keep visiting DropVPS.com!