Today we are proud to announce Submariner, a new open-source project enabling network connectivity between Kubernetes clusters. We launched the project to provide network connectivity for microservices deployed in multiple Kubernetes clusters that need to communicate with each other. This new solution overcomes barriers to connectivity between Kubernetes clusters and allows for a host of new multi-cluster implementations, such as database replication within Kubernetes across geographic regions and deploying service mesh across clusters.

Organizations are looking for Kubernetes as the standard computing platform across all public and private cloud infrastructure. Submariner allows these organizations to seamlessly connect, scale, and migrate workloads across Kubernetes clusters deployed on any cloud.

Network Connectivity Across Clusters with Submariner

Historically, Kubernetes deployments implement network virtualization, enabling containers to run on multiple nodes within the same cluster to communicate with each other. However, containers running in different Kubernetes clusters must communicate with each other through ingress controllers or node ports. Submariner now creates the necessary tunnels and routes needed to enable containers in different Kubernetes clusters to connect directly. Key features of Submariner include:

  • Compatibility and connectivity with existing clusters: Users can deploy Submariner into existing Kubernetes clusters, with the addition of Layer-3 network connectivity between pods in different clusters.
  • Secure paths: Encrypted network connectivity is implemented using IPSec tunnels.
  • Various connectivity mechanisms: While IPsec is the default connectivity mechanism out of the box, Rancher will enable different interconnectivity plugins in the near future.
  • Centralized broker : Users can register and maintain a set of healthy gateway nodes.
  • Flexible service discovery: Submariner provides service discovery across multiple Kubernetes clusters.
  • CNI compatibility: Works with popular CNI drivers such as Flannel and Calico.

Developers who are interested in downloading, installing and playing with this new networking solution should visit or follow the project on Enterprises who need assistance in deploying and managing Submariner can contact

Join the Submariner Online Meetup – March 20

To learn more about Submariner and its roadmap, join Rancher co-founder Shannon Williams and Submariner lead engineer Chris Kim at the online meetup presenting Submariner on March 20. The meetup will last about an hour and a half with plenty of time for Q&A. Book your spot now as we expect a large crowd.

Matthew runs Rancher's weekly online training sessions helping users get started with Rancher, Kubernetes and containers.