Brad Fitzpatrick
4c3ed5ab32
Move tailscaled's in-tree reactive users from of IPN bus Notify.NetMap updates to the narrower Notify.SelfChange signal introduced earlier in this series. Consumers that need additional state (peers, DNS config, etc.) fetch it on demand via the LocalAPI. It is a step toward the larger goal of not fanning Notify.NetMap out to every bus watcher on Linux/non-GUI hosts. A future change stops sending Notify.NetMap entirely on Linux and non-GUI platforms. (eventually once macOS/iOS/Windows migrate to the upcoming new Notify APIs, we'll remove ipn.Notify.NetMap entirely) Updates #12542 Change-Id: I51ea9d86bdca1909d6ac0e7d5bd3934a3a4e8516 Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
85 lines
2.0 KiB
Go
85 lines
2.0 KiB
Go
// Copyright (c) Tailscale Inc & contributors
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// SPDX-License-Identifier: BSD-3-Clause
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//go:build !plan9
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// Package health contains shared types and underlying methods for serving
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// a `/healthz` endpoint for containerboot and k8s-proxy.
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package health
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import (
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"context"
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"fmt"
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"net/http"
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"sync"
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"tailscale.com/client/local"
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"tailscale.com/ipn"
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"tailscale.com/kube/kubetypes"
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"tailscale.com/types/logger"
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)
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// Healthz is a simple health check server, if enabled it returns 200 OK if
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// this tailscale node currently has at least one tailnet IP address else
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// returns 503.
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type Healthz struct {
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sync.Mutex
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hasAddrs bool
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podIPv4 string
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logger logger.Logf
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}
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func (h *Healthz) ServeHTTP(w http.ResponseWriter, r *http.Request) {
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h.Lock()
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defer h.Unlock()
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if h.hasAddrs {
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w.Header().Add(kubetypes.PodIPv4Header, h.podIPv4)
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if _, err := w.Write([]byte("ok")); err != nil {
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http.Error(w, fmt.Sprintf("error writing status: %v", err), http.StatusInternalServerError)
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}
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} else {
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http.Error(w, "node currently has no tailscale IPs", http.StatusServiceUnavailable)
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}
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}
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func (h *Healthz) Update(healthy bool) {
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h.Lock()
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defer h.Unlock()
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if h.hasAddrs != healthy {
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h.logger("Setting healthy %v", healthy)
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}
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h.hasAddrs = healthy
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}
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func (h *Healthz) MonitorHealth(ctx context.Context, lc *local.Client) error {
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w, err := lc.WatchIPNBus(ctx, ipn.NotifyInitialNetMap)
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if err != nil {
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return fmt.Errorf("failed to watch IPN bus: %w", err)
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}
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for {
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n, err := w.Next()
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if err != nil {
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return err
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}
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if self := n.SelfChange; self != nil {
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h.Update(len(self.Addresses) != 0)
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}
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}
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}
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// RegisterHealthHandlers registers a simple health handler at /healthz.
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// A containerized tailscale instance is considered healthy if
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// it has at least one tailnet IP address.
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func RegisterHealthHandlers(mux *http.ServeMux, podIPv4 string, logger logger.Logf) *Healthz {
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h := &Healthz{
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podIPv4: podIPv4,
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logger: logger,
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}
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mux.Handle("GET /healthz", h)
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return h
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}
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