go-net-health — an active network health-probe runner in pure Go, no cgo

go-net-health is a pure-Go (no cgo) active health-probe runner: stateless network checks — HTTP or TCP — pointed at a single target address and folded into a rolling healthy / unhealthy / unknown verdict. A Probe runs one attempt of a configured check and reports pass/fail plus latency; a Runner drives it on a fixed period, honours an optional initial delay, and derives the rolling Status by stacking consecutive passes/failures against success/failure thresholds — a Kubernetes-style liveness/readiness probe as a small, embeddable library. It has no opinion on what to do with a verdict: Healthy vs Unhealthy is just a fact your own state machine acts on. Depends only on the standard library, is differential-free and dependency-free, 100% covered, and CI-green across 6 arches.

TCP & HTTP probes ready

Two stateless probe kinds: TypeTCP opens a connection and checks it succeeds; TypeHTTP issues a request and checks the response status — configurable path, method and per-probe timeout, accepting any 2xx by default or an explicit status set.

Health-check semantics ready

The behaviour a real health check needs: the HTTP probe does not follow redirects (it checks this endpoint, not where it points), surfaces the attempt latency even on failure, and uses a fresh keep-alive-disabled transport per probe so pools don’t bleed between targets.

Rolling status & Runner ready

A Runner drives a probe on a fixed period, honours a one-shot initial delay, and derives a rolling Status: SuccessThreshold consecutive passes → Healthy, FailureThreshold consecutive failures → Unhealthy, Unknown until a threshold is met. Every attempt emits a Result on a buffered channel.

Timeout vs refused ready

IsTimeout distinguishes “the probe never reached the target” from “the target actively refused”, so a caller’s grace period can apply only to unreachable targets. An injectable clock keeps wall time off the hot path for deterministic tests.

100% coverage · 6 arches ready

Every branch — timeout, connection-refused, redirect-not-followed, threshold roll-over and the buffer-drop safety valve — is covered with loopback httptest / net.Listen servers and a deterministic fake probe, under -race; 100% coverage, gofmt + go vet clean, green across all six 64-bit Go arches.

EXEC probe planned

TypeExec — running a command inside the target — is reserved. It needs an in-target agent channel this stateless network runner has no access to, so it stays out of scope until that channel exists.

ready capability complete (exit criteria met, nothing material left)
active in progress (substantial work shipped, not yet finished)
planned not started yet (or out of scope by design)

A stateless probe runner in pure Go, cgo disabled, so it cross-compiles and embeds anywhere. It implements HTTP and TCP probes with health-check-correct semantics (no redirect following, per-probe timeouts, latency on failure), a periodic Runner with initial delay and success/failure thresholds, and IsTimeout to separate unreachable targets from refusing ones. It probes and reports; the caller decides. Part of the github.com/go-net-health organization.