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Introducing Swarm-Only Mode for Mirantis Kubernetes Engine 3.5.0

Noah Merlis-Stephens - December 20, 2021

While many Mirantis Kubernetes Engine (MKE) users manage Kubernetes and Docker Swarm clusters side-by-side, there are many others with no need for Kubernetes at all. For those users, we are pleased to introduce Swarm-only mode in MKE 3.5.0.

Swarm-only mode is a new MKE configuration option — if you choose this mode during setup, the platform will only support Swarm orchestration and Docker containers. Without Kubernetes components, the resulting platform is smaller and simpler, and avoids security risks associated with Kubernetes.

Who should use Swarm-only mode?

Swarm-only mode is intended for any users who do not rely on Kubernetes. It is functionally similar to a traditional MKE configuration but offers a few clear benefits:

  • Smaller install size (more than 2GB reduction on manager nodes)
  • Fewer background processes
  • No exposure to Kubernetes vulnerabilities

For users with established infrastructure built on Docker Swarm, Swarrm-only mode immediately streamlines, optimizes, and simplifies operations to boost efficiency and security.

Enabling Swarm-only mode

Swarm-only mode is currently offered as an installation-time configuration of MKE. It cannot be enabled or disabled for an existing MKE installation. Similarly, this setting is locked during upgrades and backup/restores.

Installation of Swarm-only mode follows the same steps as a traditional MKE installation. It is enabled with the additional `--swarm-only` installation flag.

docker container run --rm -it --name ucp \
-v /var/run/docker.sock:/var/run/docker.sock \
mirantis/ucp:3.5.0 install \
--host-address <node-ip-address> \
--interactive \

Additionally, you can view the smaller required image list as follows:

docker container run --rm -it --name ucp \
-v /var/run/docker.sock:/var/run/docker.sock \
mirantis/ucp:3.5.0 images \
--list \

Swarm-only mode is a configuration mode of MKE rather than a separate product. As such, it follows the same versioning and release schedule.

Other features in Mirantis Kubernetes Engine 3.5.0

For those users who run Docker Swarm and Kubernetes clusters — or simply use Kubernetes — MKE 3.5.0 delivers a variety of new features to make cluster management easier.

  • OpsCare support (for both Swarm and Kubernetes users), enabling us to offer “DevOps-as-a-Service” — with this service, we can monitor your clusters and proactively resolve issues. Michelle Yakura walks readers through the details of OpsCare here.
  • OpenID Connect (OIDC) Single Sign On support, so you can use third-party authentication services for MKE and your clusters, whether through the web UI or API. For more details, check out Dmitrii Shishliannikov’s blog here.
  • NGINX Ingress Controller for Kubernetes, bringing the world-class reliability and scalability of an industry-standard open source ingress solution for Kubernetes users. Check out Eric Gregory's blog for more information on the switch from Istio to NGINX Ingress Controller here.

Want to explore how Mirantis Kubernetes Engine can support your orchestration needs — with Kubernetes, Docker Swarm, or both? Learn more here.

Noah Merlis-Stephens

Noah Merlis-Stephens is a Sr. Software Engineer at Mirantis.

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