Add Mesos slave attributes as node labels

- pre-create node api objects from the scheduler when offers arrive
- decline offers until nodes a registered
- turn slave attributes as k8s.mesosphere.io/attribute-* labels
- update labels from executor Register/Reregister
- watch nodes in scheduler to make non-Mesos labels available for NodeSelector matching
- add unit tests for label predicate
- add e2e test to check that slave attributes really end up as node labels

contrib/mesos/pkg/node/node.go

@@ -0,0 +1,160 @@
+/*
+Copyright 2015 The Kubernetes Authors 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 node
+
+import (
+	"encoding/json"
+	"fmt"
+	"reflect"
+	"strconv"
+	"strings"
+
+	log "github.com/golang/glog"
+	mesos "github.com/mesos/mesos-go/mesosproto"
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/api/errors"
+	client "k8s.io/kubernetes/pkg/client/unversioned"
+	"k8s.io/kubernetes/pkg/util/validation"
+)
+
+const (
+	labelPrefix = "k8s.mesosphere.io/attribute-"
+)
+
+// Create creates a new node api object with the given hostname and labels
+func Create(client *client.Client, hostName string, labels map[string]string) (*api.Node, error) {
+	n := api.Node{
+		ObjectMeta: api.ObjectMeta{
+			Name:   hostName,
+			Labels: map[string]string{"kubernetes.io/hostname": hostName},
+		},
+		Spec: api.NodeSpec{
+			ExternalID: hostName,
+		},
+		Status: api.NodeStatus{
+			Phase: api.NodePending,
+		},
+	}
+	for k, v := range labels {
+		n.Labels[k] = v
+	}
+
+	// try to create
+	return client.Nodes().Create(&n)
+}
+
+// Update updates an existing node api object with new labels
+func Update(client *client.Client, n *api.Node, labels map[string]string) (*api.Node, error) {
+	patch := struct {
+		Metadata struct {
+			Labels map[string]string `json:"labels"`
+		} `json:"metadata"`
+	}{}
+	patch.Metadata.Labels = map[string]string{}
+	for k, v := range n.Labels {
+		if !IsSlaveAttributeLabel(k) {
+			patch.Metadata.Labels[k] = v
+		}
+	}
+	for k, v := range labels {
+		patch.Metadata.Labels[k] = v
+	}
+	patchJson, _ := json.Marshal(patch)
+	log.V(4).Infof("Patching labels of node %q: %v", n.Name, string(patchJson))
+	err := client.Patch(api.MergePatchType).RequestURI(n.SelfLink).Body(patchJson).Do().Error()
+	if err != nil {
+		return nil, fmt.Errorf("error updating labels of node %q: %v", n.Name, err)
+	}
+
+	newNode, err := api.Scheme.DeepCopy(n)
+	if err != nil {
+		return nil, err
+	}
+	newNode.(*api.Node).Labels = patch.Metadata.Labels
+
+	return newNode.(*api.Node), nil
+}
+
+// CreateOrUpdate tries to create a node api object or updates an already existing one
+func CreateOrUpdate(client *client.Client, hostName string, labels map[string]string) (*api.Node, error) {
+	n, err := Create(client, hostName, labels)
+	if err == nil {
+		return n, nil
+	}
+	if !errors.IsAlreadyExists(err) {
+		return nil, fmt.Errorf("unable to register %q with the apiserver: %v", hostName, err)
+	}
+
+	// fall back to update an old node with new labels
+	n, err = client.Nodes().Get(hostName)
+	if err != nil {
+		return nil, fmt.Errorf("error getting node %q: %v", hostName, err)
+	}
+	if n == nil {
+		return nil, fmt.Errorf("no node instance returned for %q", hostName)
+	}
+	return Update(client, n, labels)
+}
+
+// IsSlaveAttributeLabel returns true iff the given label is derived from a slave attribute
+func IsSlaveAttributeLabel(l string) bool {
+	return strings.HasPrefix(l, labelPrefix)
+}
+
+// IsUpToDate returns true iff the node's slave labels match the given attributes labels
+func IsUpToDate(n *api.Node, labels map[string]string) bool {
+	slaveLabels := map[string]string{}
+	for k, v := range n.Labels {
+		if IsSlaveAttributeLabel(k) {
+			slaveLabels[k] = v
+		}
+	}
+	return reflect.DeepEqual(slaveLabels, labels)
+}
+
+// SlaveAttributesToLabels converts slave attributes into string key/value labels
+func SlaveAttributesToLabels(attrs []*mesos.Attribute) map[string]string {
+	l := map[string]string{}
+	for _, a := range attrs {
+		if a == nil {
+			continue
+		}
+
+		var v string
+		k := labelPrefix + a.GetName()
+
+		switch a.GetType() {
+		case mesos.Value_TEXT:
+			v = a.GetText().GetValue()
+		case mesos.Value_SCALAR:
+			v = strconv.FormatFloat(a.GetScalar().GetValue(), 'G', -1, 64)
+		}
+
+		if !validation.IsQualifiedName(k) {
+			log.V(3).Infof("ignoring invalid node label name %q", k)
+			continue
+		}
+
+		if !validation.IsValidLabelValue(v) {
+			log.V(3).Infof("ignoring invalid node label %s value: %q", k, v)
+			continue
+		}
+
+		l[k] = v
+	}
+	return l
+}