Create a MOSK cluster

With L2 networking templates, you can create MOSK clusters with advanced host networking configurations. For example, you can create bond interfaces on top of physical interfaces on the host or use multiple subnets to separate different types of network traffic.

You can use several host-specific L2 templates per one cluster to support different hardware configurations. For example, you can create L2 templates with a different number and layout of NICs to be applied to specific machines of one cluster.

You can also use multiple L2 templates to support different roles for nodes in a MOSK installation. You can create L2 templates with different logical interfaces and assign them to individual machines based on their roles in a MOSK cluster.

When you create a baremetal-based project in the Container Cloud web UI, the exemplary templates with the ipam/PreInstalledL2Template label are copied to this project. These templates are preinstalled during the management cluster bootstrap.

Using the L2 Templates section of the Clusters tab in the Container Cloud web UI, you can view a list of preinstalled templates and the ones that you manually create before a cluster deployment.


Mirantis does not recommend modifying L2 templates in use to prevent accidental cluster failures due to unsafe changes.

The list of risks posed by modifying L2 templates includes:

  • Services running on hosts cannot reconfigure automatically to switch to the new IP addresses and/or interfaces.

  • Connections between services are interrupted unexpectedly, which can cause data loss.

  • Incorrect configurations on hosts can lead to irrevocable loss of connectivity between services and unexpected cluster partition or disassembly.

Since MOSK 23.2.2, in the Technology Preview scope, you can create a MOSK cluster with the multi-rack topology, where cluster nodes including Kubernetes masters are distributed across multiple racks without L2 layer extension between them, and use BGP for announcement of the cluster API load balancer address and external addresses of Kubernetes load-balanced services.

Implementation of the multi-rack topology implies the use of Rack and MultiRackCluster objects that support configuration of BGP announcement of the cluster API load balancer address. For the configuration procedure, refer to Configure BGP announcement for cluster API LB address. For configuring the BGP announcement of external addresses of Kubernetes load-balanced services, refer to Configure MetalLB.

Follow the procedures described in the below subsections to configure initial settings and advanced network objects for your managed clusters.