Commit 8650e619 authored by Doug Barrett's avatar Doug Barrett
Browse files

fix(v2/httpserver): Run readiness checks concurrently and log JSON encoding errors 

Execute readiness checks using goroutines so a slow check does not block
others, matching the documented concurrent behavior. Also log JSON
encoding failures in writeJSON for debugging.
parent 1e1d490a

v2/httpserver/health.go

+30 −7
Original line number Diff line number Diff line
@@ -3,7 +3,9 @@ package httpserver 
import (

	"context"

	"encoding/json"

	"log/slog"

	"net/http"

	"sync"

)



// CheckFunc is a health check function. It should return nil when the
@@ -53,19 +55,38 @@ func (s *Server) livenessHandler(w http.ResponseWriter, _ *http.Request) { 
	writeJSON(w, http.StatusOK, healthResponse{Status: "ok"})

}



// readinessHandler runs every registered CheckFunc and returns 200 when all

// pass or 503 when one or more fail, with per-check detail in the JSON body.

// checkResult holds the outcome of a single readiness check.

type checkResult struct {

	name string

	err  error

}



// readinessHandler runs every registered CheckFunc concurrently and returns

// 200 when all pass or 503 when one or more fail, with per-check detail in

// the JSON body.

func (s *Server) readinessHandler(w http.ResponseWriter, r *http.Request) {

	resp := healthResponse{Status: "ok"}



	if len(s.checks) > 0 {

		results := make([]checkResult, len(s.checks))

		var wg sync.WaitGroup

		wg.Add(len(s.checks))



		for i, c := range s.checks {

			go func(idx int, check readinessCheck) {

				defer wg.Done()

				results[idx] = checkResult{name: check.name, err: check.fn(r.Context())}

			}(i, c)

		}

		wg.Wait()



		resp.Checks = make(map[string]string, len(s.checks))

		for _, c := range s.checks {

			if err := c.fn(r.Context()); err != nil {

		for _, res := range results {

			if res.err != nil {

				resp.Status = "error"

				resp.Checks[c.name] = err.Error()

				resp.Checks[res.name] = res.err.Error()

			} else {

				resp.Checks[c.name] = "ok"

				resp.Checks[res.name] = "ok"

			}

		}

	}
@@ -80,5 +101,7 @@ func (s *Server) readinessHandler(w http.ResponseWriter, r *http.Request) { 
func writeJSON(w http.ResponseWriter, status int, v any) {

	w.Header().Set("Content-Type", "application/json")

	w.WriteHeader(status)

	_ = json.NewEncoder(w).Encode(v)

	if err := json.NewEncoder(w).Encode(v); err != nil {

		slog.Default().Error("failed to encode health response", "error", err)

	}

}