plugin-port

Placement	compiled-in (in-process)
Source	github.com/opencharly/charly/candy/plugin-port
Version	2026.176.1500
Candy	plugin-port

This plugin is listed in charly/charly.yml’s compiled_plugins:, so its providers are compiled into the charly binary and register in-process.

Providers

The reserved words this plugin serves:

• port — verb class

What it does

The port check verb relocated into a candy: the in-container listening probe (ss/netstat) or a host-side TCP reachability dial. A HOST-COUPLED verb — its RunVerb runs against the live check engine (sdk/kit.CheckContext), served in EITHER placement: compiled-in, or OUT-OF-PROCESS via the CheckContextService reverse channel (F2). The relocation template for the other host-coupled check verbs/kinds.

Parameter schema

The CUE schema below is the authoritative grammar for this plugin’s input. It is the same single source that generates the plugin’s Go parameter types and answers the runtime Describe RPC, so this page cannot disagree with either.

schema/port.cue

// The BUILT-IN `port` plugin's OWN CUE schema — the typed plugin_input for the
// `port` verb (in-container `ss`/`netstat` listening probe, or host-side TCP dial
// for reachability). It is the SINGLE SOURCE for this plugin's params, used two ways
// (the same contract the reference examplerunverb and core `spec` use):
//
//  1. GENERATE the Go param struct — `cue exp gengotypes` (driven by task cue:gen,
//     which wraps this with `package params` + `@go(params)`) emits
//     ../params/cue_types_gen.go, so the provider decodes plugin_input into a TYPED
//     struct, never a hand-parsed map.
//  2. VALIDATE authored input AT RUNTIME — the builtin serves this source over the
//     Describe channel (InProcTransport) exactly like an external serves it over
//     gRPC; the host splices it onto the base (base ++ plugin) and validates every
//     authored `port` step's plugin_input against #PortInput.
//
// SELF-CONTAINED: it references NO base def, so it compiles standalone (gengotypes +
// the load-gate compile) AND splices onto the base — the base ++ plugin splice
// exists to detect a def-name collision with the base, not to resolve base refs.
//
// `reachable` is a SHARED base #Op field (the `addr` verb also reads it), so it STAYS
// in #Op; this plugin reproduces its `bool` shape standalone here (a bare primitive,
// NO def reference, so there is no collision when base ++ plugin compiles). The
// (distinct) box/deploy published-`port:` field is a SEPARATE schema element ([]string
// on a pod/deploy node) and is unaffected. The provider is a CheckVerbProvider — it
// dispatches IN-PROCESS via RunVerb and so keeps the live *Runner the probe / host
// dial needs (mirrors examplerunverb).
#PortInput: {
  // port — the TCP port number to probe (the verb discriminator).
  port: int & >0 & <=65535 @go(Port,type=int)
  // listening — whether the port is expected to be listening in-container (default
  // true). A tri-state pointer so an absent key means "expected listening".
  listening?: bool @go(Listening,type=*bool)
  // ip — optional host/IP for the reachability dial (default 127.0.0.1).
  ip?: string @go(IP)
  // reachable — request an outside-in host-side TCP dial instead of the in-container
  // listening probe (default true when set). Tri-state pointer.
  reachable?: bool @go(Reachable,type=*bool)
}

---

See also the candy reference for this candy’s install surface.