Working with remote Docker hosts

Lukáš Huvar Lukáš Huvar

Docker offers a convenient method for managing containers on remote hosts without exposing the Docker daemon over TCP. Using SSH as the transport protocol is secure and straightforward. This approach is excellent for deploying applications to your VPS or cloud instances.

Basic Usage

You can access a remote Docker host by setting the DOCKER_HOST environment variable with an SSH URI:

export DOCKER_HOST=ssh://user@remote-host
docker ps

This will execute docker ps on the remote machine using SSH as the transport layer.

One-liner Commands

For quick operations, you can set the environment variable inline:

DOCKER_HOST=ssh://user@remote-host docker ps
DOCKER_HOST=ssh://user@remote-host docker images
DOCKER_HOST=ssh://user@remote-host docker compose up -d

Using SSH Config

For better convenience, configure your SSH settings in ~/.ssh/config:

~/.ssh/config
Host docker-server
  HostName 192.168.1.100
  User deploy
  Port 22
  IdentityFile ~/.ssh/docker_key

Then simply reference the host alias:

export DOCKER_HOST=ssh://docker-server
docker ps

Docker Compose with Remote Hosts

Docker Compose also respects the DOCKER_HOST variable:

DOCKER_HOST=ssh://user@remote-host docker compose up -d

This is particularly useful for deploying applications to staging or production environments without complex CI/CD pipelines. You can simply deploy to the remote host using Docker Compose.

Requirements

  • Docker must be installed on both local and remote machines
  • SSH access to the remote host
  • The remote user must have permission to run Docker commands (typically in the docker group)

Security Benefits

Using SSH for Docker access provides several advantages:

  • No need to expose Docker daemon on TCP ports (2375/2376)
  • Leverages existing SSH authentication (keys, certificates)
  • All communication is encrypted