Docker Diagnostic

Fix "Cannot connect to the Docker daemon. Is the docker daemon running?"

The Docker CLI client cannot communicate with the Docker background daemon (dockerd) because the service is stopped, Docker Desktop is closed, or permissions are restricted.

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

Quick Fix Checklist

  1. macOS/Windows: Open and start the Docker Desktop application and wait for the status icon to turn green
  2. Linux (Ubuntu/Debian): Run sudo systemctl start docker && sudo systemctl enable docker
  3. WSL2: Start Docker service via sudo service docker start
  4. Check daemon status on Linux: sudo systemctl status docker