pkg/server/api: Add /healthz for load-balancer health checks

cmd/machine-config-server/bootstrap.go

@@ -2,6 +2,7 @@ package main
 
 import (
  "flag"
+ "fmt"
 
  "github.com/golang/glog"
  "github.com/openshift/machine-config-operator/pkg/server"
@@ -37,18 +38,18 @@ func runBootstrapCmd(cmd *cobra.Command, args []string) {
  glog.Infof("Version: %+v", version.Version)
 
  bs, err := server.NewBootstrapServer(bootstrapOpts.serverBaseDir, bootstrapOpts.serverKubeConfig)
-
  if err != nil {
  glog.Exitf("Machine Config Server exited with error: %v", err)
  }
 
- apiHandler := server.NewServerAPIHandler(bs)
- secureServer := server.NewAPIServer(apiHandler, rootOpts.sport, false, rootOpts.cert, rootOpts.key)
- insecureServer := server.NewAPIServer(apiHandler, rootOpts.isport, true, "", "")
+ secureServer := *bs
+ secureServer.Addr = fmt.Sprintf(":%d", rootOpts.sport)
+ insecureServer := *bs
+ insecureServer.Addr = fmt.Sprintf(":%d", rootOpts.isport)
 
  stopCh := make(chan struct{})
- go secureServer.Serve()
- go insecureServer.Serve()
+ go secureServer.ListenAndServeTLS(rootOpts.cert, rootOpts.key)
+ go insecureServer.ListenAndServe()
  <-stopCh
  panic("not possible")
 }

cmd/machine-config-server/start.go

@@ -2,6 +2,7 @@ package main
 
 import (
  "flag"
+ "fmt"
 
  "github.com/golang/glog"
  "github.com/openshift/machine-config-operator/pkg/server"
@@ -45,13 +46,14 @@ func runStartCmd(cmd *cobra.Command, args []string) {
  glog.Exitf("Machine Config Server exited with error: %v", err)
  }
 
- apiHandler := server.NewServerAPIHandler(cs)
- secureServer := server.NewAPIServer(apiHandler, rootOpts.sport, false, rootOpts.cert, rootOpts.key)
- insecureServer := server.NewAPIServer(apiHandler, rootOpts.isport, true, "", "")
+ secureServer := *cs
+ secureServer.Addr = fmt.Sprintf(":%d", rootOpts.sport)
+ insecureServer := *cs
+ insecureServer.Addr = fmt.Sprintf(":%d", rootOpts.isport)
 
  stopCh := make(chan struct{})
- go secureServer.Serve()
- go insecureServer.Serve()
+ go secureServer.ListenAndServeTLS(rootOpts.cert, rootOpts.key)
+ go insecureServer.ListenAndServe()
  <-stopCh
  panic("not possible")
 }

pkg/server/api.go

@@ -6,6 +6,7 @@ import (
  "net/http"
  "path"
 
+ ignv2_2types "github.com/coreos/ignition/config/v2_2/types"
  "github.com/golang/glog"
 )
 
@@ -17,69 +18,24 @@ type poolRequest struct {
  machinePool string
 }
 
-// APIServer provides the HTTP(s) endpoint
-// for providing the machine configs.
-type APIServer struct {
- handler *APIHandler
- port int
- insecure bool
- cert string
- key string
-}
-
-// NewAPIServer initializes a new API server
-// that runs the Machine Config Server as a
-// handler.
-func NewAPIServer(a *APIHandler, p int, is bool, c, k string) *APIServer {
- return &APIServer{
- handler: a,
- port: p,
- insecure: is,
- cert: c,
- key: k,
- }
-}
+type getConfig func(request poolRequest) (*ignv2_2types.Config, error)
 
-// Serve launches the API Server.
-func (a *APIServer) Serve() {
+func newHandler(getConfig getConfig) http.Handler {
  mux := http.NewServeMux()
- mux.Handle(apiPathConfig, a.handler)
-
- mcs := &http.Server{
- Addr: fmt.Sprintf(":%v", a.port),
- Handler: mux,
- }
-
- glog.Info("launching server")
- if a.insecure {
- // Serve a non TLS server.
- if err := mcs.ListenAndServe(); err != http.ErrServerClosed {
- glog.Exitf("Machine Config Server exited with error: %v", err)
- }
- } else {
- if err := mcs.ListenAndServeTLS(a.cert, a.key); err != http.ErrServerClosed {
- glog.Exitf("Machine Config Server exited with error: %v", err)
- }
- }
+ mux.Handle("/healthz", &healthHandler{})
+ mux.Handle(apiPathConfig, &configHandler{getConfig: getConfig})
+ mux.Handle("/", &defaultHandler{})
+ return mux
 }
 
-// APIHandler is the HTTP Handler for the
-// Machine Config Server.
-type APIHandler struct {
- server Server
-}
-
-// NewServerAPIHandler initializes a new API handler
-// for the Machine Config Server.
-func NewServerAPIHandler(s Server) *APIHandler {
- return &APIHandler{
- server: s,
- }
+// configHandler is the HTTP Handler for machine configuration.
+type configHandler struct {
+ getConfig getConfig
 }
 
 // ServeHTTP handles the requests for the machine config server
 // API handler.
-func (sh *APIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+func (h *configHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
  if r.Method != http.MethodGet && r.Method != http.MethodHead {
  w.Header().Set("Content-Length", "0")
  w.WriteHeader(http.StatusMethodNotAllowed)
@@ -96,7 +52,7 @@ func (sh *APIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
  machinePool: path.Base(r.URL.Path),
  }
 
- conf, err := sh.server.GetConfig(cr)
+ conf, err := h.getConfig(cr)
  if err != nil {
  w.Header().Set("Content-Length", "0")
  w.WriteHeader(http.StatusInternalServerError)
@@ -129,3 +85,33 @@ func (sh *APIHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
  glog.Errorf("failed to write %v response: %v", cr, err)
  }
 }
+
+type healthHandler struct{}
+
+// ServeHTTP handles /healthz requests.
+func (h *healthHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Length", "0")
+
+ if r.URL.Path == "/healthz" {
+ if r.Method == http.MethodGet || r.Method == http.MethodHead {
+ w.WriteHeader(http.StatusNoContent)
+ return
+ }
+
+ w.WriteHeader(http.StatusMethodNotAllowed)
+ return
+ }
+
+ w.WriteHeader(http.StatusNotFound)
+ return
+}
+
+// defaultHandler is the HTTP Handler for backstopping invalid requests.
+type defaultHandler struct{}
+
+// ServeHTTP handles invalid requests.
+func (h *defaultHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+ w.Header().Set("Content-Length", "0")
+ w.WriteHeader(http.StatusNotFound)
+ return
+}

pkg/server/api_test.go

@@ -23,16 +23,16 @@ type checkResponse func(t *testing.T, response *http.Response)
 type scenario struct {
  name string
  request *http.Request
- serverFunc func(poolRequest) (*ignv2_2types.Config, error)
+ getConfig  getConfig
  checkResponse checkResponse
 }
 
-func TestAPIHandler(t *testing.T) {
+func TestHandler(t *testing.T) {
  scenarios := []scenario{
  {
  name: "get non-config path that does not exist",
  request: httptest.NewRequest(http.MethodGet, "http://testrequest/does-not-exist", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
  return nil, nil
  },
  checkResponse: func(t *testing.T, response *http.Response) {
@@ -44,7 +44,7 @@ func TestAPIHandler(t *testing.T) {
  {
  name: "get config path that does not exist",
  request: httptest.NewRequest(http.MethodGet, "http://testrequest/config/does-not-exist", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
  return new(ignv2_2types.Config), fmt.Errorf("not acceptable")
  },
  checkResponse: func(t *testing.T, response *http.Response) {
@@ -56,7 +56,7 @@ func TestAPIHandler(t *testing.T) {
  {
  name: "get config path that exists",
  request: httptest.NewRequest(http.MethodGet, "http://testrequest/config/master", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
  return new(ignv2_2types.Config), nil
  },
  checkResponse: func(t *testing.T, response *http.Response) {
@@ -69,7 +69,7 @@ func TestAPIHandler(t *testing.T) {
  {
  name: "head config path that exists",
  request: httptest.NewRequest(http.MethodHead, "http://testrequest/config/master", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
  return new(ignv2_2types.Config), nil
  },
  checkResponse: func(t *testing.T, response *http.Response) {
@@ -79,23 +79,107 @@ func TestAPIHandler(t *testing.T) {
  checkBodyLength(t, response, 0)
  },
  },
+ {
+ name: "get /healthz",
+ request: httptest.NewRequest(http.MethodGet, "http://testrequest/healthz", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return new(ignv2_2types.Config), nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNoContent)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "head /healthz",
+ request: httptest.NewRequest(http.MethodHead, "http://testrequest/healthz", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return new(ignv2_2types.Config), nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNoContent)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "get health path that does not exist",
+ request: httptest.NewRequest(http.MethodGet, "http://testrequest/healthz-does-not-exist", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNotFound)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "get health child that does not exist",
+ request: httptest.NewRequest(http.MethodGet, "http://testrequest/healthz/does-not-exist", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNotFound)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "get root",
+ request: httptest.NewRequest(http.MethodGet, "http://testrequest/", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNotFound)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "post root",
+ request: httptest.NewRequest(http.MethodPost, "http://testrequest/", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusNotFound)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
  {
  name: "post non-config path that does not exist",
  request: httptest.NewRequest(http.MethodPost, "http://testrequest/post", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
  return nil, nil
  },
  checkResponse: func(t *testing.T, response *http.Response) {
- checkStatus(t, response, http.StatusMethodNotAllowed)
+ checkStatus(t, response, http.StatusNotFound)
  checkContentLength(t, response, 0)
  checkBodyLength(t, response, 0)
  },
  },
  {
  name: "post config path that exists",
  request: httptest.NewRequest(http.MethodPost, "http://testrequest/config/master", nil),
- serverFunc: func(poolRequest) (*ignv2_2types.Config, error) {
- return new(ignv2_2types.Config), nil
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
+ },
+ checkResponse: func(t *testing.T, response *http.Response) {
+ checkStatus(t, response, http.StatusMethodNotAllowed)
+ checkContentLength(t, response, 0)
+ checkBodyLength(t, response, 0)
+ },
+ },
+ {
+ name: "post /healthz",
+ request: httptest.NewRequest(http.MethodPost, "http://testrequest/healthz", nil),
+ getConfig: func(poolRequest) (*ignv2_2types.Config, error) {
+ return nil, nil
  },
  checkResponse: func(t *testing.T, response *http.Response) {
  checkStatus(t, response, http.StatusMethodNotAllowed)
@@ -108,10 +192,7 @@ func TestAPIHandler(t *testing.T) {
  for _, scenario := range scenarios {
  t.Run(scenario.name, func(t *testing.T) {
  w := httptest.NewRecorder()
- ms := &mockServer{
- GetConfigFn: scenario.serverFunc,
- }
- handler := NewServerAPIHandler(ms)
+ handler := newHandler(scenario.getConfig)
  handler.ServeHTTP(w, scenario.request)
 
  resp := w.Result()