Docker Swarm is the built-in orchestrator that comes with Docker Engine out of the box. It was introduced in Docker Engine release 1.12 (the release numbers changed after 1.13 to four-digit numbers) as swarm mode. There was a previous swarm approach currently known as Legacy Swarm, which was closer in architecture to Kubernetes. It required an external key-value store database, among other components. Swarm mode is different from this because it includes everything needed for the orchestrator to work out of the box.
The Swarm architecture is quite simple as it provides secure communications between components by default. Before deploying a Docker Swarm cluster, let's review its main features:
- Container orchestration for multiple nodes is included on each Docker Engine: This means that we can deploy a cluster without any other software. Docker Engine provides all the required components to deploy and manage the cluster out of the box.
- Node roles can be changed...