Merge pull request #457 from dchen1107/minionlogs

Add support to query kubelet's logs and cadvisor's stats through apiserver by passing rawquery

pkg/kubelet/kubelet.go

@@ -59,6 +59,8 @@ type CadvisorInterface interface {
 }
 
 // New creates a new Kubelet.
+// TODO: currently it is only called by test code.
+// Need cleanup.
 func New() *Kubelet {
 	return &Kubelet{}
 }
@@ -77,6 +79,7 @@ type Kubelet struct {
 	HTTPCheckFrequency time.Duration
 	pullLock           sync.Mutex
 	HealthChecker      health.HealthChecker
+	LogServer          http.Handler
 }
 
 type manifestUpdate struct {
@@ -94,6 +97,9 @@ const (
 // RunKubelet starts background goroutines. If config_path, manifest_url, or address are empty,
 // they are not watched. Never returns.
 func (kl *Kubelet) RunKubelet(dockerEndpoint, configPath, manifestURL string, etcdServers []string, address string, port uint) {
+	if kl.LogServer == nil {
+		kl.LogServer = http.StripPrefix("/logs/", http.FileServer(http.Dir("/var/log/")))
+	}
 	if kl.CadvisorClient == nil {
 		var err error
 		kl.CadvisorClient, err = cadvisor.NewClient("http://127.0.0.1:5000")
@@ -814,3 +820,9 @@ func (kl *Kubelet) healthy(container api.Container, dockerContainer *docker.APIC
 	}
 	return kl.HealthChecker.HealthCheck(container)
 }
+
+// Returns logs of current machine.
+func (kl *Kubelet) ServeLogs(w http.ResponseWriter, req *http.Request) {
+	// TODO: whitelist logs we are willing to serve
+	kl.LogServer.ServeHTTP(w, req)
+}

pkg/kubelet/server.go

@@ -47,6 +47,7 @@ type kubeletInterface interface {
 	GetRootInfo(req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
 	GetMachineInfo() (*info.MachineInfo, error)
 	GetPodInfo(name string) (api.PodInfo, error)
+	ServeLogs(w http.ResponseWriter, req *http.Request)
 }
 
 func (s *Server) error(w http.ResponseWriter, err error) {
@@ -131,6 +132,8 @@ func (s *Server) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 		}
 		w.Header().Add("Content-type", "application/json")
 		w.Write(data)
+	case strings.HasPrefix(u.Path, "/logs/"):
+		s.Kubelet.ServeLogs(w, req)
 	default:
 		s.DelegateHandler.ServeHTTP(w, req)
 	}

pkg/kubelet/server_test.go

@@ -23,7 +23,9 @@ import (
 	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
+	"net/http/httputil"
 	"reflect"
+	"strings"
 	"testing"
 
 	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
@@ -37,6 +39,7 @@ type fakeKubelet struct {
 	containerInfoFunc func(podID, containerName string, req *info.ContainerInfoRequest) (*info.ContainerInfo, error)
 	rootInfoFunc      func(query *info.ContainerInfoRequest) (*info.ContainerInfo, error)
 	machineInfoFunc   func() (*info.MachineInfo, error)
+	logFunc           func(w http.ResponseWriter, req *http.Request)
 }
 
 func (fk *fakeKubelet) GetPodInfo(name string) (api.PodInfo, error) {
@@ -55,6 +58,10 @@ func (fk *fakeKubelet) GetMachineInfo() (*info.MachineInfo, error) {
 	return fk.machineInfoFunc()
 }
 
+func (fk *fakeKubelet) ServeLogs(w http.ResponseWriter, req *http.Request) {
+	fk.logFunc(w, req)
+}
+
 type serverTestFramework struct {
 	updateChan      chan manifestUpdate
 	updateReader    *channelReader
@@ -253,3 +260,31 @@ func TestMachineInfo(t *testing.T) {
 		t.Errorf("received wrong data: %#v", receivedInfo)
 	}
 }
+
+func TestServeLogs(t *testing.T) {
+	fw := makeServerTest()
+
+	content := string(`<pre><a href="kubelet.log">kubelet.log</a><a href="google.log">google.log</a></pre>`)
+
+	fw.fakeKubelet.logFunc = func(w http.ResponseWriter, req *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		w.Header().Add("Content-Type", "text/html")
+		w.Write([]byte(content))
+	}
+
+	resp, err := http.Get(fw.testHTTPServer.URL + "/logs/")
+	if err != nil {
+		t.Fatalf("Got error GETing: %v", err)
+	}
+	defer resp.Body.Close()
+
+	body, err := httputil.DumpResponse(resp, true)
+	if err != nil {
+		// copying the response body did not work
+		t.Errorf("Cannot copy resp: %#v", err)
+	}
+	result := string(body)
+	if !strings.Contains(result, "kubelet.log") || !strings.Contains(result, "google.log") {
+		t.Errorf("Received wrong data: %s", result)
+	}
+}