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Concepts

Firewalls dropped, the shell stayed alive.

Andrios Robert

• 1 min read

That’s the promise of combining Mosh with OpenShift—true persistent remote access for containerized workloads, even in hostile or unstable networks.

Mosh (mobile shell) is a remote terminal application designed to survive roaming, IP changes, and transient connectivity drops. Unlike SSH, it maintains session state over UDP, enabling smooth command-line work without constant reconnections. When paired with OpenShift, Red Hat’s Kubernetes-based container platform, Mosh can give developers and operators a resilient edge in managing ephemeral pods and remote clusters.

Why Mosh on OpenShift

Traditional SSH sessions to OpenShift pods or nodes can be fragile. VPN hiccups, mobile connections, or changing network routes interrupt the workflow. Mosh solves this by:

  • Using UDP to keep the connection alive.
  • Predicting keystrokes to reduce latency impact.
  • Automatically reconnecting without user intervention.

In containerized environments, these traits allow for more stable troubleshooting, live debugging, and CLI-driven deployment adjustments.

Deploying Mosh in OpenShift

To run Mosh inside OpenShift, you need:

  1. A container image with Mosh installed.
  2. Proper UDP port exposure and routing.
  3. Role-based access controls for security.

Example steps:

  1. Build an image:
FROM registry.access.redhat.com/ubi8/ubi
RUN yum install -y mosh && yum clean all
  1. Create an OpenShift Deployment or Pod definition using the image.
  2. Expose the service with a Service object configured for Mosh’s default UDP port range (60000-61000).
  3. Adjust OpenShift networking rules or use a dedicated route to pass UDP traffic.
  4. Connect from your local machine using:
mosh --ssh="oc rsh"<pod-name>

Security Considerations

  • Lock UDP ranges to trusted networks.
  • Integrate with existing OpenShift authentication (OAuth, service accounts).
  • Monitor and log Mosh connections for audit compliance.

When to Use

  • Long-running CLI-based operations on remote OpenShift clusters.
  • Mobile or low-bandwidth network environments.
  • Multi-region operations where network routes are unstable.

Mosh adds reliability without sacrificing speed. On OpenShift, it turns fragile CLI sessions into durable tools you can trust when things go wrong.

Test it yourself. Deploy Mosh on OpenShift with hoop.dev and get interactive, persistent access to your workloads in minutes—see it live now.