How Can I Use a Remote Docker Engine with My Local Docker CLI?

Hey there!

One way of of doing this is, uou can connect your local Docker CLI to a remote Docker Engine by setting the DOCKER_HOST environment variable.

Here’s how to do it:

• First, make sure that you have Docker is installed on your Droplet and running.
• Then, on your Droplet, edit the Docker service file to enable the remote API:

sudo nano /lib/systemd/system/docker.service

Find the line that starts with ExecStart and modify it to include the -H flag for the remote API:

ExecStart=/usr/bin/dockerd -H fd:// -H tcp://0.0.0.0:2375

Save and restart Docker:

sudo systemctl daemon-reload
sudo systemctl restart docker

On your local machine, you can now connect to the remote engine by running:

export DOCKER_HOST=tcp://<your-droplet-ip>:2375
docker ps

For production setups, exposing the Docker API on an open port is risky. Here’s how to secure it:

• Option 1: Use SSH Tunnels Create an SSH tunnel to your remote Droplet:

  ssh -L 2375:localhost:2375 root@<your-droplet-ip>
  

  Then point your DOCKER_HOST to localhost instead:

  export DOCKER_HOST=tcp://localhost:2375
  docker ps
  

• Option 2: Use Certificates Configure Docker to use TLS certificates for authentication. The official Docker docs have step-by-step instructions for this.

Regarding the benefits, I would say that they are:

• Allows you to manage your remote Docker environment without SSHing into the server.
• Useful for CI/CD pipelines and multi-user collaboration.

And for the downsides:

• If not secured properly, it can expose your server to unauthorized access.
• Networking overhead might slightly increase latency.

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If you want to dive deeper into Docker, I’ve got a free eBook that might help: Introduction to Docker. It covers the basics of Docker, setting up environments, and much more.

Also, here is a great video that also covers the above!

Hope this helps!

• Bobby