What is the Docker Daemon?

The Docker Daemon (dockerd) is the background service that manages Docker containers, images, networks, and storage. It listens for Docker API requests and executes them.

  • It runs on the host machine (your computer or server).
  • It is responsible for building, running, and distributing containers.
  • It communicates with the Docker Client (CLI) when you run commands like docker run or docker build.

How the Docker Daemon Works

When you run a Docker command (e.g., docker run nginx), here’s what happens:

  1. The Docker Client sends the command to the Docker Daemon.
  2. The Docker Daemon checks if the image (nginx) exists locally.
  3. If not, it pulls the image from Docker Hub (or another registry).
  4. The daemon creates and starts the container.

The Docker Daemon is the core engine behind Docker, managing containers, images, and networks.

🔹 It runs in the background and listens for Docker commands.
🔹 It interacts with registries (like Docker Hub) to pull images.
🔹 It must be secured since it has high-level system access.