vendor: revendor

Signed-off-by: Lucas Servén Marín <lserven@gmail.com>

vendor/github.com/metalmatze/signal/healthcheck/handler.go

@@ -0,0 +1,103 @@
+// Copyright 2020 by the contributors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package healthcheck
+
+import (
+	"encoding/json"
+	"net/http"
+	"sync"
+)
+
+// basicHandler is a basic Handler implementation.
+type basicHandler struct {
+	http.ServeMux
+	checksMutex     sync.RWMutex
+	livenessChecks  map[string]Check
+	readinessChecks map[string]Check
+}
+
+// NewHandler creates a new basic Handler
+func NewHandler() Handler {
+	h := &basicHandler{
+		livenessChecks:  make(map[string]Check),
+		readinessChecks: make(map[string]Check),
+	}
+	h.Handle("/live", http.HandlerFunc(h.LiveEndpoint))
+	h.Handle("/ready", http.HandlerFunc(h.ReadyEndpoint))
+	return h
+}
+
+func (s *basicHandler) LiveEndpoint(w http.ResponseWriter, r *http.Request) {
+	s.handle(w, r, s.livenessChecks)
+}
+
+func (s *basicHandler) ReadyEndpoint(w http.ResponseWriter, r *http.Request) {
+	s.handle(w, r, s.readinessChecks, s.livenessChecks)
+}
+
+func (s *basicHandler) AddLivenessCheck(name string, check Check) {
+	s.checksMutex.Lock()
+	defer s.checksMutex.Unlock()
+	s.livenessChecks[name] = check
+}
+
+func (s *basicHandler) AddReadinessCheck(name string, check Check) {
+	s.checksMutex.Lock()
+	defer s.checksMutex.Unlock()
+	s.readinessChecks[name] = check
+}
+
+func (s *basicHandler) collectChecks(checks map[string]Check, resultsOut map[string]string, statusOut *int) {
+	s.checksMutex.RLock()
+	defer s.checksMutex.RUnlock()
+	for name, check := range checks {
+		if err := check(); err != nil {
+			*statusOut = http.StatusServiceUnavailable
+			resultsOut[name] = err.Error()
+		} else {
+			resultsOut[name] = "OK"
+		}
+	}
+}
+
+func (s *basicHandler) handle(w http.ResponseWriter, r *http.Request, checks ...map[string]Check) {
+	if r.Method != http.MethodGet {
+		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
+		return
+	}
+
+	checkResults := make(map[string]string)
+	status := http.StatusOK
+	for _, checks := range checks {
+		s.collectChecks(checks, checkResults, &status)
+	}
+
+	// write out the response code and content type header
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	w.WriteHeader(status)
+
+	// if ?hide=1, return an empty body. Kubernetes only cares about the
+	// HTTP status code, so we won't waste bytes on the full body.
+	if r.URL.Query().Get("hide") == "1" {
+		_, _ = w.Write([]byte("{}\n"))
+		return
+	}
+
+	// otherwise, write the JSON body ignoring any encoding errors (which
+	// shouldn't really be possible since we're encoding a map[string]string).
+	encoder := json.NewEncoder(w)
+	encoder.SetIndent("", "    ")
+	_ = encoder.Encode(checkResults)
+}