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"
)

var (
	execprober = execprobe.New()
	httprober  = httprobe.New()
	tcprober   = tcprobe.New()
)

func (kl *Kubelet) probeContainer(p *api.Probe, podFullName string, podUID types.UID, status api.PodStatus, container api.Container) (probe.Status, error) {
	if p.Exec != nil {
		return execprober.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 httprober.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 tcprober.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:
		port := param.IntVal
		if port > 0 && port < 65536 {
			return port, nil
		}
		return port, fmt.Errorf("invalid port number: %v", port)
	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
			}
		}
		if port > 0 && port < 65536 {
			return port, nil
		}
		return port, fmt.Errorf("invalid port number: %v", port)
	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
}