Submariner is a tool for networking between Pods and Services in Kubernetes clusters. 

According to the project’s website, as teams continue to adopt Kubernetes, they are discovering that they need to deploy and manage multiple clusters in order to enable capabilities like geo-redundancy, scale, and fault isolation.

Submariner was created so that companies could have their applications and services across multiple cloud providers, data centers, and regions.

Key features of Submariner include:

  • Cross-cluster L3 connectivity 
  • Service Discovery across clusters
  • An easy-to-use development tool called subctl
  • Support for interconnecting clusters with overlapping CIDRs

The most recent release is v0.11.0, which was focused on providing bug fixes, improving stability, and improving the integration with Open Cluster Management. 

According to the project’s roadmap, features in the works include network policy across clusters, support for finer-grained connectivity policies, dynamic rounding with BGP, testing with Istio, and scale improvements. 

More information about the project is available here