tailscale/cmd/containerboot/healthz.go

58 lines
1.3 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
//go:build linux
package main
import (
"fmt"
"log"
"net/http"
"sync"
"tailscale.com/kube/kubetypes"
)
// healthz is a simple health check server, if enabled it returns 200 OK if
// this tailscale node currently has at least one tailnet IP address else
// returns 503.
type healthz struct {
sync.Mutex
hasAddrs bool
podIPv4 string
}
func (h *healthz) ServeHTTP(w http.ResponseWriter, r *http.Request) {
h.Lock()
defer h.Unlock()
if h.hasAddrs {
w.Header().Add(kubetypes.PodIPv4Header, h.podIPv4)
if _, err := w.Write([]byte("ok")); err != nil {
http.Error(w, fmt.Sprintf("error writing status: %v", err), http.StatusInternalServerError)
}
} else {
http.Error(w, "node currently has no tailscale IPs", http.StatusServiceUnavailable)
}
}
func (h *healthz) update(healthy bool) {
h.Lock()
defer h.Unlock()
if h.hasAddrs != healthy {
log.Println("Setting healthy", healthy)
}
h.hasAddrs = healthy
}
// healthHandlers registers a simple health handler at /healthz.
// A containerized tailscale instance is considered healthy if
// it has at least one tailnet IP address.
func healthHandlers(mux *http.ServeMux, podIPv4 string) *healthz {
h := &healthz{podIPv4: podIPv4}
mux.Handle("GET /healthz", h)
return h
}