Vendor main dependencies.

vendor/github.com/coreos/pkg/health/health.go

@@ -0,0 +1,127 @@
+package health
+
+import (
+	"expvar"
+	"fmt"
+	"log"
+	"net/http"
+
+	"github.com/coreos/pkg/httputil"
+)
+
+// Checkables should return nil when the thing they are checking is healthy, and an error otherwise.
+type Checkable interface {
+	Healthy() error
+}
+
+// Checker provides a way to make an endpoint which can be probed for system health.
+type Checker struct {
+	// Checks are the Checkables to be checked when probing.
+	Checks []Checkable
+
+	// Unhealthyhandler is called when one or more of the checks are unhealthy.
+	// If not provided DefaultUnhealthyHandler is called.
+	UnhealthyHandler UnhealthyHandler
+
+	// HealthyHandler is called when all checks are healthy.
+	// If not provided, DefaultHealthyHandler is called.
+	HealthyHandler http.HandlerFunc
+}
+
+func (c Checker) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	unhealthyHandler := c.UnhealthyHandler
+	if unhealthyHandler == nil {
+		unhealthyHandler = DefaultUnhealthyHandler
+	}
+
+	successHandler := c.HealthyHandler
+	if successHandler == nil {
+		successHandler = DefaultHealthyHandler
+	}
+
+	if r.Method != "GET" {
+		w.Header().Set("Allow", "GET")
+		w.WriteHeader(http.StatusMethodNotAllowed)
+		return
+	}
+
+	if err := Check(c.Checks); err != nil {
+		unhealthyHandler(w, r, err)
+		return
+	}
+
+	successHandler(w, r)
+}
+
+type UnhealthyHandler func(w http.ResponseWriter, r *http.Request, err error)
+
+type StatusResponse struct {
+	Status  string                 `json:"status"`
+	Details *StatusResponseDetails `json:"details,omitempty"`
+}
+
+type StatusResponseDetails struct {
+	Code    int    `json:"code,omitempty"`
+	Message string `json:"message,omitempty"`
+}
+
+func Check(checks []Checkable) (err error) {
+	errs := []error{}
+	for _, c := range checks {
+		if e := c.Healthy(); e != nil {
+			errs = append(errs, e)
+		}
+	}
+
+	switch len(errs) {
+	case 0:
+		err = nil
+	case 1:
+		err = errs[0]
+	default:
+		err = fmt.Errorf("multiple health check failure: %v", errs)
+	}
+
+	return
+}
+
+func DefaultHealthyHandler(w http.ResponseWriter, r *http.Request) {
+	err := httputil.WriteJSONResponse(w, http.StatusOK, StatusResponse{
+		Status: "ok",
+	})
+	if err != nil {
+		// TODO(bobbyrullo): replace with logging from new logging pkg,
+		// once it lands.
+		log.Printf("Failed to write JSON response: %v", err)
+	}
+}
+
+func DefaultUnhealthyHandler(w http.ResponseWriter, r *http.Request, err error) {
+	writeErr := httputil.WriteJSONResponse(w, http.StatusInternalServerError, StatusResponse{
+		Status: "error",
+		Details: &StatusResponseDetails{
+			Code:    http.StatusInternalServerError,
+			Message: err.Error(),
+		},
+	})
+	if writeErr != nil {
+		// TODO(bobbyrullo): replace with logging from new logging pkg,
+		// once it lands.
+		log.Printf("Failed to write JSON response: %v", err)
+	}
+}
+
+// ExpvarHandler is copied from https://golang.org/src/expvar/expvar.go, where it's sadly unexported.
+func ExpvarHandler(w http.ResponseWriter, r *http.Request) {
+	w.Header().Set("Content-Type", "application/json; charset=utf-8")
+	fmt.Fprintf(w, "{\n")
+	first := true
+	expvar.Do(func(kv expvar.KeyValue) {
+		if !first {
+			fmt.Fprintf(w, ",\n")
+		}
+		first = false
+		fmt.Fprintf(w, "%q: %s", kv.Key, kv.Value)
+	})
+	fmt.Fprintf(w, "\n}\n")
+}