Docker Engine swarm mode overview


10 months ago

Available from docker engine 1.12.0. Main features:

  • self-contained: no extra software is needed for orchestration, docker engine is enough.
  • safe communication: all communication uses TLS (self-assigned but it could use a custom CA)
  • discovery: there is an internal DNS for services and the swarm balances the requests among services
  • load balancing: services can be exposed via ports so external balancers will work

didn't remember:

  • descentralized: node roles are defined in runtime, a swarm can be built from a single image.
  • scaling: the swarm manages the declared number of tasks per service and adapts the state.
  • reconciliation: mantains the state if there is a failure/change.
  • multi-host networking: you can define an overlay network and the swarm manages the addresses.
  • rolling updates: service updates can be incremental and the delay can be controlled among different nodes. Rollback is easy.