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558f4bea41
This add the infrastructure to let other middleware report their health status back to the health middleware. A health.Healther interface is introduced and a middleware needs to implement that. A middleware that supports healthchecks is statically configured. Every second each supported middleware is queried and the global health state is updated. Actual tests have been disabled as no other middleware implements this at the moment.
70 lines
1.1 KiB
Go
70 lines
1.1 KiB
Go
// Package health implements an HTTP handler that responds to health checks.
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package health
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import (
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"io"
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"log"
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"net"
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"net/http"
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"sync"
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)
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var once sync.Once
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type health struct {
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Addr string
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ln net.Listener
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mux *http.ServeMux
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// A slice of Healthers that the health middleware will poll every second for their health status.
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h []Healther
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sync.RWMutex
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ok bool // ok is the global boolean indicating an all healthy middleware stack
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}
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func (h *health) Startup() error {
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if h.Addr == "" {
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h.Addr = defAddr
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}
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once.Do(func() {
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ln, err := net.Listen("tcp", h.Addr)
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if err != nil {
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log.Printf("[ERROR] Failed to start health handler: %s", err)
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return
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}
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h.ln = ln
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h.mux = http.NewServeMux()
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h.mux.HandleFunc(path, func(w http.ResponseWriter, r *http.Request) {
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if h.Ok() {
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w.WriteHeader(http.StatusOK)
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io.WriteString(w, ok)
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return
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}
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w.WriteHeader(http.StatusServiceUnavailable)
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})
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go func() {
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http.Serve(h.ln, h.mux)
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}()
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})
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return nil
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}
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func (h *health) Shutdown() error {
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if h.ln != nil {
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return h.ln.Close()
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}
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return nil
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}
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const (
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ok = "OK"
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defAddr = ":8080"
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path = "/health"
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)
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