Add Kubernetes Probes

pkg/probez.go

@@ -0,0 +1,51 @@
+package courier
+
+import (
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+// Determines if the server is healthy or not.
+func (s *Server) IsHealthy() bool {
+	s.RLock()
+	defer s.RUnlock()
+	return s.healthy
+}
+
+// Determines if the server is ready or not.
+func (s *Server) IsReady() bool {
+	s.RLock()
+	defer s.RUnlock()
+	return s.ready
+}
+
+// Set the server health state to the status bool.
+func (s *Server) SetHealthy(status bool) {
+	s.Lock()
+	defer s.Unlock()
+	s.healthy = status
+}
+
+// Set the server ready state to the status bool.
+func (s *Server) SetReady(status bool) {
+	s.Lock()
+	defer s.Unlock()
+	s.ready = status
+}
+
+func (s *Server) Healthz(c *gin.Context) {
+	status := http.StatusOK
+	if !s.IsHealthy() {
+		status = http.StatusServiceUnavailable
+	}
+	c.Data(status, "text/plain", []byte(http.StatusText(status)))
+}
+
+func (s *Server) Readyz(c *gin.Context) {
+	status := http.StatusOK
+	if !s.IsReady() {
+		status = http.StatusServiceUnavailable
+	}
+	c.Data(status, "text/plain", []byte(http.StatusText(status)))
+}

pkg/server.go

@@ -74,14 +74,15 @@ func New(conf config.Config) (s *Server, err error) {
 // Server defines the courier service and its webhook handlers.
 type Server struct {
 	sync.RWMutex
-	conf    config.Config
-	srv     *http.Server
-	router  *gin.Engine
-	store   store.Store
-	started time.Time
-	healthy bool
-	url     string
-	echan   chan error
+	conf    config.Config // Primary source of truth for server configuration
+	srv     *http.Server  // The HTTP server for handling requests
+	router  *gin.Engine   // The gin router for muxing requests to handlers
+	store   store.Store   // Manages certificate and password storage
+	healthy bool          // Indicates that the service is online and healthy
+	ready   bool          // Indicates that the service is ready to accept requests
+	started time.Time     // The timestamp the server was started (for uptime)
+	url     string        // The endpoint that the server is hosted on
+	echan   chan error    // Sending errors on this channel stops the server
 }
 
 // Serve API requests.
@@ -146,6 +147,12 @@ func (s *Server) Shutdown() (err error) {
 
 // Setup the routes for the courier service.
 func (s *Server) setupRoutes() (err error) {
+	// Kubernetes probe endpoints -- add routes before middleware to ensure these
+	// endpoints are not logged or subject to other handling that may harm correctness
+	s.router.GET("/healthz", s.Healthz)
+	s.router.GET("/livez", s.Healthz)
+	s.router.GET("/readyz", s.Readyz)
+
 	middlewares := []gin.HandlerFunc{
 		gin.Logger(),
 		gin.Recovery(),
@@ -176,13 +183,6 @@ func (s *Server) setupRoutes() (err error) {
 	return nil
 }
 
-// Set the healthy status of the server.
-func (s *Server) SetHealthy(healthy bool) {
-	s.Lock()
-	s.healthy = healthy
-	s.Unlock()
-}
-
 // Set the URL of the server from the socket
 func (s *Server) SetURL(sock net.Listener) {
 	s.Lock()

pkg/version.go

@@ -11,18 +11,12 @@ const (
 	VersionReleaseNumber = 1
 )
 
-// Set the GitVersion via -ldflags="-X 'github.com/rotationalio/ensign/pkg.GitVersion=$(git rev-parse --short HEAD)'"
+// Set the GitVersion via -ldflags="-X 'github.com/trisacrypto/courier/pkg.GitVersion=$(git rev-parse --short HEAD)'"
 var GitVersion string
 
 // Returns the semantic version for the current build.
 func Version() string {
-	var versionCore string
-	if VersionPatch > 0 || VersionReleaseLevel != "" {
-		versionCore = fmt.Sprintf("%d.%d.%d", VersionMajor, VersionMinor, VersionPatch)
-	} else {
-		versionCore = fmt.Sprintf("%d.%d", VersionMajor, VersionMinor)
-	}
-
+	versionCore := fmt.Sprintf("%d.%d.%d", VersionMajor, VersionMinor, VersionPatch)
 	if VersionReleaseLevel != "" {
 		if VersionReleaseNumber > 0 {
 			versionCore = fmt.Sprintf("%s-%s.%d", versionCore, VersionReleaseLevel, VersionReleaseNumber)