cornus port-forward

Forward one or more local ports to a deployment's container ports, reaching ports that were never published to a host or exposed through a Service.

Synopsis

cornus port-forward [flags] <name> <ports...>

Description

cornus port-forward binds a local listener per mapping and forwards each accepted connection over its own tunnel to the first instance of a deployment, much like kubectl port-forward. It stays in the foreground until Ctrl-C (or SIGTERM).

For a cluster connection profile it tunnels each connection straight to the workload pod over the Kubernetes pods/portforward SPDY subresource using your kubeconfig credentials (the server's own ServiceAccount usually cannot), falling back to the server proxy only when the direct attempt cannot open a tunnel. For a non-cluster profile it tunnels through the cornus server, which bridges to the container. Either way it reaches ports that were never published to a host or exposed via a Service.

Each port mapping is LOCAL:REMOTE (or a bare PORT for the same local and container port), optionally with a /tcp or /udp suffix in Compose ports notation (default tcp), for example 5353:53/udp. Ports must be in 1..65535. A /udp mapping forwards datagrams instead of a byte stream and is supported on every host backend — dockerhost, containerd, bare, and incus; Kubernetes port-forward is TCP-only, so such mappings are skipped with a warning.

The connection is resolved from --server, otherwise from the selected connection profile (see cornus config). See Networking and conduits for how port-forward fits the larger set of ways to reach workloads.

Flags

Flag	Env var	Default	Description
--server	CORNUS_SERVER	—	Remote cornus server URL (http(s):// or ws(s)://). Falls back to the selected connection profile.
--address	—	127.0.0.1	Local address to bind the listeners on.
--via-server / --no-via-server	CORNUS_VIA_SERVER	profile	Route the forward through the cornus server proxy instead of connecting to the pod directly with your kubeconfig (cluster profiles only). --no-via-server forces the direct path. Overrides CORNUS_VIA_SERVER and the profile.

Positional arguments:

• <name> — deployment name to forward to (required).
• <ports...> — one or more LOCAL:REMOTE[/tcp|/udp] mappings, or a bare PORT (required).

Examples

Forward local port 8080 to container port 80:

cornus port-forward web 8080:80

Forward several ports at once, binding on all interfaces:

cornus port-forward --address 0.0.0.0 web 8080:80 5432:5432

Forward a UDP port (any host backend; not Kubernetes):

cornus port-forward dns 5353:53/udp

Force the server-proxy path instead of the direct-to-pod path:

cornus port-forward --via-server web 8080:80