From 0c1d90bf5f23ff2c8b070e8488659f006381d3ae Mon Sep 17 00:00:00 2001
From: "Dr. Stefan Schimanski" <stefan.schimanski@gmail.com>
Date: Thu, 5 Nov 2015 12:29:39 +0100
Subject: [PATCH] Add ListWithoutKubelet to mesos cloud provider

---
 pkg/cloudprovider/providers/mesos/client.go | 38 ++++++++++++++++---
 pkg/cloudprovider/providers/mesos/mesos.go  | 42 ++++++++++++++++++---
 2 files changed, 70 insertions(+), 10 deletions(-)

diff --git a/pkg/cloudprovider/providers/mesos/client.go b/pkg/cloudprovider/providers/mesos/client.go
index da7d5e98551..70d8ada92c3 100644
--- a/pkg/cloudprovider/providers/mesos/client.go
+++ b/pkg/cloudprovider/providers/mesos/client.go
@@ -49,13 +49,14 @@ type mesosClient struct {
 }
 
 type slaveNode struct {
-	hostname  string
-	resources *api.NodeResources
+	hostname       string
+	kubeletRunning bool
+	resources      *api.NodeResources
 }
 
 type mesosState struct {
 	clusterName string
-	nodes       map[string]*slaveNode
+	nodes       map[string]*slaveNode // by hostname
 }
 
 type stateCache struct {
@@ -160,7 +161,7 @@ func unpackIPv4(ip uint32) string {
 	return ipv4.String()
 }
 
-// listSlaves returns a (possibly cached) list of slave nodes.
+// listSlaves returns a (possibly cached) map of slave nodes by hostname.
 // Callers must not mutate the contents of the returned slice.
 func (c *mesosClient) listSlaves(ctx context.Context) (map[string]*slaveNode, error) {
 	return c.state.nodes(ctx)
@@ -225,12 +226,36 @@ func parseMesosState(blob []byte) (*mesosState, error) {
 			Hostname  string                 `json:"hostname"`  // ex: 10.22.211.18, or slave-123.nowhere.com
 			Resources map[string]interface{} `json:"resources"` // ex: {"mem": 123, "ports": "[31000-3200]"}
 		} `json:"slaves"`
+		Frameworks []*struct {
+			Id        string `json:"id"`  // ex: 20151105-093752-3745622208-5050-1-0000
+			Pid       string `json:"pid"` // ex: scheduler(1)@192.168.65.228:57124
+			Executors []*struct {
+				SlaveId    string `json:"slave_id"`    // ex: 20151105-093752-3745622208-5050-1-S1
+				ExecutorId string `json:"executor_id"` // ex: 6704d375c68fee1e_k8sm-executor
+				Name       string `json:"name"`        // ex: Kubelet-Executor
+			} `json:"executors"`
+		} `json:"frameworks"`
 	}
+
 	state := &State{ClusterName: defaultClusterName}
 	if err := json.Unmarshal(blob, state); err != nil {
 		return nil, err
 	}
-	nodes := map[string]*slaveNode{}
+
+	executorSlaveIds := map[string]struct{}{}
+	for _, f := range state.Frameworks {
+		for _, e := range f.Executors {
+			// Note that this simple comparison breaks when we support more than one
+			// k8s instance in a cluster. At the moment this is not possible for
+			// a number of reasons.
+			// TODO(sttts): find way to detect executors of this k8s instance
+			if e.Name == "Kubelet-Executor" {
+				executorSlaveIds[e.SlaveId] = struct{}{}
+			}
+		}
+	}
+
+	nodes := map[string]*slaveNode{} // by hostname
 	for _, slave := range state.Slaves {
 		if slave.Hostname == "" {
 			continue
@@ -264,6 +289,9 @@ func parseMesosState(blob []byte) (*mesosState, error) {
 			}
 			log.V(4).Infof("node %q reporting capacity %v", node.hostname, cap)
 		}
+		if _, ok := executorSlaveIds[slave.Id]; ok {
+			node.kubeletRunning = true
+		}
 		nodes[node.hostname] = node
 	}
 
diff --git a/pkg/cloudprovider/providers/mesos/mesos.go b/pkg/cloudprovider/providers/mesos/mesos.go
index e376f1a0a1a..538c3de5a10 100644
--- a/pkg/cloudprovider/providers/mesos/mesos.go
+++ b/pkg/cloudprovider/providers/mesos/mesos.go
@@ -30,8 +30,16 @@ import (
 	"k8s.io/kubernetes/pkg/cloudprovider"
 )
 
+const (
+	ProviderName = "mesos"
+
+	// KubernetesExecutorName is shared between contrib/mesos and Mesos cloud provider.
+	// Because cloud provider -> contrib dependencies are forbidden, this constant
+	// is defined here, not in contrib.
+	KubernetesExecutorName = "Kubelet-Executor"
+)
+
 var (
-	ProviderName  = "mesos"
 	CloudProvider *MesosCloud
 
 	noHostNameSpecified = errors.New("No hostname specified")
@@ -208,9 +216,7 @@ func (c *MesosCloud) InstanceID(name string) (string, error) {
 	return "", nil
 }
 
-// List lists instances that match 'filter' which is a regular expression
-// which must match the entire instance name (fqdn).
-func (c *MesosCloud) List(filter string) ([]string, error) {
+func (c *MesosCloud) listNodes() (map[string]*slaveNode, error) {
 	//TODO(jdef) use a timeout here? 15s?
 	ctx, cancel := context.WithCancel(context.TODO())
 	defer cancel()
@@ -223,6 +229,16 @@ func (c *MesosCloud) List(filter string) ([]string, error) {
 		log.V(2).Info("no slaves found, are any running?")
 		return nil, nil
 	}
+	return nodes, nil
+}
+
+// List lists instances that match 'filter' which is a regular expression
+// which must match the entire instance name (fqdn).
+func (c *MesosCloud) List(filter string) ([]string, error) {
+	nodes, err := c.listNodes()
+	if err != nil {
+		return nil, err
+	}
 	filterRegex, err := regexp.Compile(filter)
 	if err != nil {
 		return nil, err
@@ -233,7 +249,23 @@ func (c *MesosCloud) List(filter string) ([]string, error) {
 			addr = append(addr, node.hostname)
 		}
 	}
-	return addr, err
+	return addr, nil
+}
+
+// ListWithKubelet list those instance which have no running kubelet, i.e. the
+// Kubernetes executor.
+func (c *MesosCloud) ListWithoutKubelet() ([]string, error) {
+	nodes, err := c.listNodes()
+	if err != nil {
+		return nil, err
+	}
+	addr := make([]string, 0, len(nodes))
+	for _, n := range nodes {
+		if !n.kubeletRunning {
+			addr = append(addr, n.hostname)
+		}
+	}
+	return addr, nil
 }
 
 // NodeAddresses returns the addresses of the specified instance.