Set apiserver-count flag

upup/models/config/components/kube-apiserver/kube-apiserver.options

@@ -15,3 +15,4 @@ KubeAPIServer:
   LogLevel: 2
   AllowPrivileged: true
   Image: {{ Image "kube-apiserver" }}
+  APIServerCount: {{ APIServerCount }}

upup/pkg/fi/cloudup/template_functions.go

@@ -6,6 +6,7 @@ import (
 	"fmt"
 	"github.com/golang/glog"
 	"k8s.io/kops/upup/pkg/api"
+	"k8s.io/kops/upup/pkg/fi"
 	"k8s.io/kops/util/pkg/vfs"
 	"math/big"
 	"net"
@@ -98,6 +99,8 @@ func (tf *TemplateFunctions) AddTo(dest template.FuncMap) {
 	dest["GetInstanceGroup"] = tf.GetInstanceGroup
 
 	dest["CloudTags"] = tf.CloudTags
+
+	dest["APIServerCount"] = tf.APIServerCount
 }
 
 func (tf *TemplateFunctions) EtcdClusterMemberTags(etcd *api.EtcdClusterSpec, m *api.EtcdMemberSpec) map[string]string {
@@ -240,3 +243,19 @@ func (tf *TemplateFunctions) GetInstanceGroup(name string) (*api.InstanceGroup,
 	}
 	return nil, fmt.Errorf("InstanceGroup %q not found", name)
 }
+
+// APIServerCount returns the value for the kubeapiserver --apiserver-count flag
+func (tf *TemplateFunctions) APIServerCount() int {
+	count := 0
+	for _, ig := range tf.instanceGroups {
+		if !ig.IsMaster() {
+			continue
+		}
+		size := fi.IntValue(ig.Spec.MaxSize)
+		if size == 0 {
+			size = fi.IntValue(ig.Spec.MinSize)
+		}
+		count += size
+	}
+	return count
+}