rest.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 minion

import (
	"errors"
	"fmt"
	"net"
	"strconv"

	"github.com/GoogleCloudPlatform/kubernetes/pkg/api"
	kerrors "github.com/GoogleCloudPlatform/kubernetes/pkg/api/errors"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/api/validation"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/apiserver"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/labels"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/master/ports"
	"github.com/GoogleCloudPlatform/kubernetes/pkg/runtime"
)

// REST implements the RESTStorage interface, backed by a MinionRegistry.
type REST struct {
	registry Registry
}

// NewREST returns a new REST.
func NewREST(m Registry) *REST {
	return &REST{
		registry: m,
	}
}

var ErrDoesNotExist = errors.New("The requested resource does not exist.")
var ErrNotHealty = errors.New("The requested minion is not healthy.")

func (rs *REST) Create(ctx api.Context, obj runtime.Object) (<-chan apiserver.RESTResult, error) {
	minion, ok := obj.(*api.Minion)
	if !ok {
		return nil, fmt.Errorf("not a minion: %#v", obj)
	}

	if errs := validation.ValidateMinion(minion); len(errs) > 0 {
		return nil, kerrors.NewInvalid("minion", minion.Name, errs)
	}

	api.FillObjectMetaSystemFields(ctx, &minion.ObjectMeta)

	return apiserver.MakeAsync(func() (runtime.Object, error) {
		// TODO: Need to fill in any server-set fields (uid, timestamp, etc) before
		// returning minion. Can't do it properly at the moment because the registry
		// healthchecking, which might cause it to not return the minion at all. Fix
		// this after we move the healthchecking out of the minion registry.
		err := rs.registry.CreateMinion(ctx, minion)
		if err != nil {
			return nil, err
		}
		return minion, nil
	}), nil
}

func (rs *REST) Delete(ctx api.Context, id string) (<-chan apiserver.RESTResult, error) {
	minion, err := rs.registry.GetMinion(ctx, id)
	if minion == nil {
		return nil, ErrDoesNotExist
	}
	if err != nil {
		return nil, err
	}
	return apiserver.MakeAsync(func() (runtime.Object, error) {
		return &api.Status{Status: api.StatusSuccess}, rs.registry.DeleteMinion(ctx, id)
	}), nil
}

func (rs *REST) Get(ctx api.Context, id string) (runtime.Object, error) {
	minion, err := rs.registry.GetMinion(ctx, id)
	if minion == nil {
		return nil, ErrDoesNotExist
	}
	return minion, err
}

func (rs *REST) List(ctx api.Context, label, field labels.Selector) (runtime.Object, error) {
	return rs.registry.ListMinions(ctx)
}

func (rs *REST) New() runtime.Object {
	return &api.Minion{}
}

func (rs *REST) Update(ctx api.Context, obj runtime.Object) (<-chan apiserver.RESTResult, error) {
	minion, ok := obj.(*api.Minion)
	if !ok {
		return nil, fmt.Errorf("not a minion: %#v", obj)
	}

	// TODO: GetMinion will health check the minion, but we shouldn't require the minion to be
	// running for updating labels.
	oldMinion, err := rs.registry.GetMinion(ctx, minion.Name)
	if err != nil {
		return nil, err
	}
	if errs := validation.ValidateMinionUpdate(oldMinion, minion); len(errs) > 0 {
		return nil, kerrors.NewInvalid("minion", minion.Name, errs)
	}

	return apiserver.MakeAsync(func() (runtime.Object, error) {
		err := rs.registry.UpdateMinion(ctx, minion)
		if err != nil {
			return nil, err
		}
		return rs.registry.GetMinion(ctx, minion.Name)
	}), nil
}

func (rs *REST) toApiMinion(name string) *api.Minion {
	return &api.Minion{ObjectMeta: api.ObjectMeta{Name: name}}
}

// ResourceLocation returns a URL to which one can send traffic for the specified minion.
func (rs *REST) ResourceLocation(ctx api.Context, id string) (string, error) {
	minion, err := rs.registry.GetMinion(ctx, id)
	if err != nil {
		return "", err
	}
	host := minion.HostIP
	if host == "" {
		host = minion.Name
	}
	// TODO: Minion webservers should be secure!
	return "http://" + net.JoinHostPort(host, strconv.Itoa(ports.KubeletPort)), nil
}