daemon 🐳 Docker

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

The docker CLI can’t talk to the Docker engine — it isn’t running, or your user can’t access the socket.

Seen on: Docker Linux

Meaning

The docker command is just a client; the daemon does the work. On Linux the socket is root-owned unless you’re in the docker group. On macOS/Windows, Docker Desktop must be running.

Common causes

  • Docker daemon/Desktop not started
  • User not in docker group (permission denied on docker.sock)
  • DOCKER_HOST / context pointing elsewhere
  • Rootless Docker uses a different socket path

⚡ Quick fix

  1. Start Docker: sudo systemctl start docker or open Docker Desktop
  2. Add yourself to the group: sudo usermod -aG docker $USER then log out/in
  3. Check docker context ls and echo $DOCKER_HOST

Detailed fix by platform

Linux

  1. Enable and verify:
    bash
    sudo systemctl enable --now docker
sudo usermod -aG docker $USER && newgrp docker
docker info

How to diagnose

  1. Daemon — Is it running?
  2. Permission — “permission denied” on docker.sock?
  3. Context — Which context/host is the CLI using?

🧠 Still stuck? Analyze your error

Paste the full message, response headers or stack trace — we'll detect the platform and point to the most likely cause.