Core Idea
Docker’s ecosystem splits into a client and a server, wrapped by the projects that standardize and host it: OCI for the specs, CNCF for the ecosystem, Moby for the engine’s building blocks.
- Client and server: the CLI on one side, the daemon on the other.
- Container-related projects: OCI, CNCF, and the Moby project.
- The map that the rest of the book’s commands live on.
Client & Server
The client called as Docker CLI and The server called docker CLI.
Docker cli use to deploying and managing containers.It converts simple commands into API requests and sends them to the engine.
The engine comprises all the server-side components that run and manage containers.
Tip
The client and engine can be on the same host or connected over the network.
Container Related Projects
OCI (Open Container Initiative)
- A governance council responsible for low-level container-related standards.
- At the time of writing, the OCI maintains three standards called specs:
- The image-spec
- The runtime-spec
- The distribution-spec
Rail tracks analogy
When the size and properties of rail tracks were standardized, it gave entrepreneurs in the rail industry confidence the trains, carriages, signaling systems, platforms, and other rail infrastructure they built would work with the standardized tracks — nobody wanted competing standards for track sizes.
For example:
- The Docker builder (BuildKit) creates OCI compliant-images
- Docker uses an OCI-compliant runtime to create OCI-compliant containers
- Docker Hub implements the OCI distribution spec and is an OCI-compliant registry
cncf (The CloudNative Computing Foundation)
Instead of creating and maintaining container-related specifications, the cncf hosts important projects such as Kubernetes, containerd, Notary, Prometheus, Cilium, and lots more.
cncf projects pass through the following three phases or stages:
- Sandbox
- Incubating
- Graduated
Moby Project
Docker created the Moby project as a community-led place for developers to build specialized tools for building container platforms.