Docker is a pioneering open-source platform that, through the innovative use of containerization technology, enables the encapsulation of applications along with all their dependencies, libraries, tools, and configuration settings within lightweight, independent, and highly portable units known as “containers.”
Docker networking is built on an open design called the Container Network Model, implemented through libnetwork and extended by pluggable drivers. This article covers the theory behind Docker networking and walks through creating and testing single-host bridge networks, including name resolution and port mapping.
Beyond basic bridge networks, Docker can connect containers directly to existing physical VLANs, resolve service names automatically, and distribute traffic across a Swarm cluster. This article covers the macvlan driver, Docker's built-in service discovery, and Swarm's ingress load balancing mesh.
Overlay networks let containers on different hosts communicate as if they shared a single flat network, forming the backbone of most cloud-native microservices apps. This article covers how to build, encrypt, and test a Docker overlay network across a Swarm cluster, and explains the VXLAN tunneling technology powering it behind the scenes.
Containers get a temporary writable layer by default, which disappears the moment a container is deleted — fine for scratch data, but risky for anything worth keeping. This article explains how Docker volumes decouple persistent data from container lifecycles, and walks through creating, using, and sharing them safely.
Docker's security model is built on layered defense, combining well-established Linux kernel technologies with sensible defaults out of the box. This article explains how namespaces, control groups, capabilities, mandatory access control, and seccomp work together to isolate and secure containers.
