cannot connect to the Docker daemon — how to fix

Q: Custom socket or remote daemon

If the daemon uses a custom socket or TCP address, set DOCKER_HOST : ``` export DOCKER_HOST=unix:///run/user/1000/docker.sock # or TCP export DOCKER_HOST=tcp://192.168.1.10:2376 ```

Quick Answer

# macOS / Windows: start Docker Desktop
open -a Docker          # macOS
# Or launch Docker Desktop from Applications

# Linux: start the daemon
sudo systemctl start docker
sudo systemctl enable docker   # auto-start on boot

# Verify
docker info

When this happens

Cannot connect to the Docker daemon at unix:///var/run/docker.sock.
Is the docker daemon running?

The Docker CLI cannot reach the daemon because it is not running, or the socket path is wrong.

Other causes & fixes

Check daemon status (Linux)

sudo systemctl status docker
# If inactive:
sudo systemctl start docker

Custom socket or remote daemon

If the daemon uses a custom socket or TCP address, set DOCKER_HOST:

export DOCKER_HOST=unix:///run/user/1000/docker.sock
# or TCP
export DOCKER_HOST=tcp://192.168.1.10:2376

Rootless Docker socket

# The socket lives under the user runtime directory
export DOCKER_HOST=unix://$XDG_RUNTIME_DIR/docker.sock