create pkg/probe as successor to pkg/health.

pkg/kubelet/probe.go

+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 kubelet
+
+import (
+	"fmt"
+	"strconv"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/probe"
+	execprobe "github.com/GoogleCloudPlatform/kubernetes/pkg/probe/exec"
+	httprobe "github.com/GoogleCloudPlatform/kubernetes/pkg/probe/http"
+	tcprobe "github.com/GoogleCloudPlatform/kubernetes/pkg/probe/tcp"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/types"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util/exec"
+
+	"github.com/golang/glog"
+)
+
+func (kl *Kubelet) makeLivenessProbeRunner(p *api.LivenessProbe, podFullName string, podUID types.UID, status api.PodStatus, container api.Container) (probe.Status, error) {
+	if p.Exec != nil {
+		return execprobe.Probe(kl.newExecInContainer(podFullName, podUID, container))
+	}
+	if p.HTTPGet != nil {
+		port, err := extractPort(p.HTTPGet.Port, container)
+		if err != nil {
+			return probe.Unknown, err
+		}
+		return httprobe.Probe(extractGetParams(p.HTTPGet, status, port))
+	}
+	if p.TCPSocket != nil {
+		port, err := extractPort(p.TCPSocket.Port, container)
+		if err != nil {
+			return probe.Unknown, err
+		}
+		return tcprobe.Probe(status.PodIP, port)
+	}
+	glog.Warningf("Failed to find probe builder for %s %+v", container.Name, container.LivenessProbe)
+	return probe.Unknown, nil
+}
+
+func extractGetParams(action *api.HTTPGetAction, status api.PodStatus, port int) (string, int, string) {
+	host := action.Host
+	if host == "" {
+		host = status.PodIP
+	}
+	return host, port, action.Path
+}
+
+func extractPort(param util.IntOrString, container api.Container) (int, error) {
+	port := -1
+	var err error
+	switch param.Kind {
+	case util.IntstrInt:
+		return param.IntVal, nil
+	case util.IntstrString:
+		port = findPortByName(container, param.StrVal)
+		if port == -1 {
+			// Last ditch effort - maybe it was an int stored as string?
+			if port, err = strconv.Atoi(param.StrVal); err != nil {
+				return port, err
+			}
+		}
+		return port, nil
+	default:
+		return port, fmt.Errorf("IntOrString had no kind: %+v", param)
+	}
+}
+
+// findPortByName is a helper function to look up a port in a container by name.
+// Returns the HostPort if found, -1 if not found.
+func findPortByName(container api.Container, portName string) int {
+	for _, port := range container.Ports {
+		if port.Name == portName {
+			return port.HostPort
+		}
+	}
+	return -1
+}
+
+type execInContainer struct {
+	run func() ([]byte, error)
+}
+
+func (kl *Kubelet) newExecInContainer(podFullName string, podUID types.UID, container api.Container) exec.Cmd {
+	return execInContainer{func() ([]byte, error) {
+		return kl.RunInContainer(podFullName, podUID, container.Name, container.LivenessProbe.Exec.Command)
+	}}
+}
+
+func (eic execInContainer) CombinedOutput() ([]byte, error) {
+	return eic.run()
+}
+
+func (eic execInContainer) SetDir(dir string) {
+	//unimplemented
+}

pkg/probe/doc.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 probe contains utilities for health probing, as well as health status information.
+package probe

pkg/probe/exec/exec.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 exec
+
+import (
+	"strings"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/probe"
+	uexec "github.com/GoogleCloudPlatform/kubernetes/pkg/util/exec"
+
+	"github.com/golang/glog"
+)
+
+const defaultHealthyOutput = "ok"
+
+func Probe(e uexec.Cmd) (probe.Status, error) {
+	data, err := e.CombinedOutput()
+	glog.V(4).Infof("health check response: %s", string(data))
+	if err != nil {
+		return probe.Unknown, err
+	}
+	if strings.ToLower(string(data)) != defaultHealthyOutput {
+		return probe.Unhealthy, nil
+	}
+	return probe.Healthy, nil
+}

pkg/probe/http/http.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 http
+
+import (
+	"net"
+	"net/http"
+	"net/url"
+	"strconv"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/probe"
+
+	"github.com/golang/glog"
+)
+
+var client = &http.Client{}
+
+// Probe returns a ProbeRunner capable of running an http check.
+func Probe(host string, port int, path string) (probe.Status, error) {
+	return DoHTTPProbe(formatURL(host, port, path), client)
+}
+
+type HTTPGetInterface interface {
+	Get(u string) (*http.Response, error)
+}
+
+// DoHTTPProbe checks if a GET request to the url succeeds.
+// If the HTTP response code is successful (i.e. 400 > code >= 200), it returns Healthy.
+// If the HTTP response code is unsuccessful or HTTP communication fails, it returns Unhealthy.
+// This is exported because some other packages may want to do direct HTTP probes.
+func DoHTTPProbe(url string, client HTTPGetInterface) (probe.Status, error) {
+	res, err := client.Get(url)
+	if err != nil {
+		glog.V(1).Infof("HTTP probe error: %v", err)
+		return probe.Unhealthy, nil
+	}
+	defer res.Body.Close()
+	if res.StatusCode >= http.StatusOK && res.StatusCode < http.StatusBadRequest {
+		return probe.Healthy, nil
+	}
+	glog.V(1).Infof("Health check failed for %s, Response: %v", url, *res)
+	return probe.Unhealthy, nil
+}
+
+// formatURL formats a URL from args.  For testability.
+func formatURL(host string, port int, path string) string {
+	u := url.URL{
+		Scheme: "http",
+		Host:   net.JoinHostPort(host, strconv.Itoa(port)),
+		Path:   path,
+	}
+	return u.String()
+}

pkg/probe/probe.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 probe
+
+type Status int
+
+// Status values must be one of these constants.
+const (
+	Healthy Status = iota
+	Unhealthy
+	Unknown
+)
+
+func (s Status) String() string {
+	switch s {
+	case Healthy:
+		return "healthy"
+	case Unhealthy:
+		return "unhealthy"
+	default:
+		return "unknown"
+	}
+}

pkg/probe/tcp/tcp.go

+/*
+Copyright 2015 Google Inc. All rights reserved.
+
+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 tcp
+
+import (
+	"net"
+	"strconv"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/probe"
+
+	"github.com/golang/glog"
+)
+
+func Probe(host string, port int) (probe.Status, error) {
+	return DoTCPProbe(net.JoinHostPort(host, strconv.Itoa(port)))
+}
+
+// DoTCPProbe checks that a TCP socket to the address can be opened.
+// If the socket can be opened, it returns Healthy.
+// If the socket fails to open, it returns Unhealthy.
+// This is exported because some other packages may want to do direct TCP probes.
+func DoTCPProbe(addr string) (probe.Status, error) {
+	conn, err := net.Dial("tcp", addr)
+	if err != nil {
+		return probe.Unhealthy, nil
+	}
+	err = conn.Close()
+	if err != nil {
+		glog.Errorf("unexpected error closing health check socket: %v (%#v)", err, err)
+	}
+	return probe.Healthy, nil
+}