Questios about Docker architecture

General
1

Hello everyone,

I’m learning about Docker architecture and had two quick questions:

  1. When I run docker info and see both Client and Server, is the Server the Docker daemon?
  2. How can one Docker daemon communicate with another?

I’m still new to Docker, so I really appreciate any guidance. Thanks in advance!

2

Yes, the server is the Docker daemon and some info about the host where it is running, but one daemon doesn’t communicate with another. Doesn’t have to. Only the client communicates with the daemon using TCP or Unix sockets on unix-like systems or named pipes on Windows.

3

Thank you for explaining this concept of Docker architecture.

4

Minor addition to what @rimelek wrote: if the Swarm mode is actived and multiple Docker hosts are joined to a Swarm cluster, then the nodes would communicate cluster state based on the raft consensus algorith syncronising the raft logs amongst the nodes. Swarm allows using docker overlay networks, which allow spanning container networks accross nodes using vxlan. These control and data communications use udp and tcp connections amongst the nodes.