From 06a413bff9ba7547a39e985e33d146894b431dca Mon Sep 17 00:00:00 2001
From: Justin Santa Barbara <justin@fathomdb.com>
Date: Tue, 13 Sep 2016 16:59:09 -0400
Subject: [PATCH] Hotfix for clusters with InstanceGroupName not defined

---
 upup/pkg/api/kubeletconfig.go            | 10 ++++------
 upup/pkg/fi/nodeup/command.go            | 10 ++++++----
 upup/pkg/fi/nodeup/template_functions.go | 25 ++++++++++++++++++++----
 3 files changed, 31 insertions(+), 14 deletions(-)

diff --git a/upup/pkg/api/kubeletconfig.go b/upup/pkg/api/kubeletconfig.go
index e3164bf831..eca5ee88ac 100644
--- a/upup/pkg/api/kubeletconfig.go
+++ b/upup/pkg/api/kubeletconfig.go
@@ -22,13 +22,11 @@ func BuildKubeletConfigSpec(cluster *Cluster, instanceGroup *InstanceGroup) (*Ku
 		utils.JsonMergeStruct(c, cluster.Spec.Kubelet)
 	}
 
-	if instanceGroup != nil {
-		for k, v := range instanceGroup.Spec.NodeLabels {
-			if c.NodeLabels == nil {
-				c.NodeLabels = make(map[string]string)
-			}
-			c.NodeLabels[k] = v
+	for k, v := range instanceGroup.Spec.NodeLabels {
+		if c.NodeLabels == nil {
+			c.NodeLabels = make(map[string]string)
 		}
+		c.NodeLabels[k] = v
 	}
 
 	return c, nil
diff --git a/upup/pkg/fi/nodeup/command.go b/upup/pkg/fi/nodeup/command.go
index 5727ab36ad..2c91f3fc3d 100644
--- a/upup/pkg/fi/nodeup/command.go
+++ b/upup/pkg/fi/nodeup/command.go
@@ -21,7 +21,7 @@ const MaxAttemptsWithNoProgress = 100
 type NodeUpCommand struct {
 	config         *NodeUpConfig
 	cluster        *api.Cluster
-	instancegroup  *api.InstanceGroup
+	instanceGroup  *api.InstanceGroup
 	ConfigLocation string
 	ModelDir       vfs.Path
 	CacheDir       string
@@ -109,16 +109,18 @@ func (c *NodeUpCommand) Run(out io.Writer) error {
 	if c.config.InstanceGroupName != "" {
 		instanceGroupLocation := configBase.Join("instancegroup", c.config.InstanceGroupName)
 
-		c.instancegroup = &api.InstanceGroup{}
+		c.instanceGroup = &api.InstanceGroup{}
 		b, err := instanceGroupLocation.ReadFile()
 		if err != nil {
 			return fmt.Errorf("error loading InstanceGroup %q: %v", instanceGroupLocation, err)
 		}
 
-		err = utils.YamlUnmarshal(b, c.instancegroup)
+		err = utils.YamlUnmarshal(b, c.instanceGroup)
 		if err != nil {
 			return fmt.Errorf("error parsing InstanceGroup %q: %v", instanceGroupLocation, err)
 		}
+	} else {
+		glog.Warningf("No instance group defined in nodeup config")
 	}
 
 	err := evaluateSpec(c.cluster)
@@ -164,7 +166,7 @@ func (c *NodeUpCommand) Run(out io.Writer) error {
 
 	loader := NewLoader(c.config, c.cluster, assets, tags)
 
-	tf, err := newTemplateFunctions(c.config, c.cluster, c.instancegroup, tags)
+	tf, err := newTemplateFunctions(c.config, c.cluster, c.instanceGroup, tags)
 	if err != nil {
 		return fmt.Errorf("error initializing: %v", err)
 	}
diff --git a/upup/pkg/fi/nodeup/template_functions.go b/upup/pkg/fi/nodeup/template_functions.go
index 817ec8f7f7..c096b52d7b 100644
--- a/upup/pkg/fi/nodeup/template_functions.go
+++ b/upup/pkg/fi/nodeup/template_functions.go
@@ -67,11 +67,28 @@ func newTemplateFunctions(nodeupConfig *NodeUpConfig, cluster *api.Cluster, inst
 		return nil, fmt.Errorf("KeyStore not set")
 	}
 
-	kubeletConfigSpec, err := api.BuildKubeletConfigSpec(t.cluster, t.instanceGroup)
-	if err != nil {
-		return nil, fmt.Errorf("error building kubelet config: %v", err)
+	{
+		instanceGroup := t.instanceGroup
+		if instanceGroup == nil {
+			// Old clusters might not have exported instance groups
+			// in that case we build a synthetic instance group with the information that BuildKubeletConfigSpec needs
+			// TODO: Remove this once we have a stable release
+			glog.Warningf("Building a synthetic instance group")
+			instanceGroup = &api.InstanceGroup{}
+			instanceGroup.Name = "synthetic"
+			if t.IsMaster() {
+				instanceGroup.Spec.Role = api.InstanceGroupRoleMaster
+			} else {
+				instanceGroup.Spec.Role = api.InstanceGroupRoleNode
+			}
+			t.instanceGroup = instanceGroup
+		}
+		kubeletConfigSpec, err := api.BuildKubeletConfigSpec(cluster, instanceGroup)
+		if err != nil {
+			return nil, fmt.Errorf("error building kubelet config: %v", err)
+		}
+		t.kubeletConfig = kubeletConfigSpec
 	}
-	t.kubeletConfig = kubeletConfigSpec
 
 	return t, nil
 }