From 9e437e41e7b3da68b8dd3663d6a18f48f6e28c9d Mon Sep 17 00:00:00 2001
From: Markus Lehtonen <markus.lehtonen@intel.com>
Date: Fri, 5 May 2023 12:35:44 +0300
Subject: [PATCH] topology-updater: use node IP in the default configz URI

Use node IP (instead of node name) in the default value of
-kubelet-config-uri. Should make the default deployment more robust,
making it work in scenarios where node name does not resolve to the node
ip, e.g. nodename != hostname.
---
 cmd/nfd-topology-updater/main.go                         | 9 +++++----
 deployment/components/topology-updater/env.yaml          | 7 +++++++
 .../components/topology-updater/kustomization.yaml       | 4 ++++
 .../templates/topologyupdater.yaml                       | 4 ++++
 docs/reference/topology-updater-commandline-reference.md | 2 +-
 5 files changed, 21 insertions(+), 5 deletions(-)
 create mode 100644 deployment/components/topology-updater/env.yaml

diff --git a/cmd/nfd-topology-updater/main.go b/cmd/nfd-topology-updater/main.go
index 88012e2aaa..6fb96a979b 100644
--- a/cmd/nfd-topology-updater/main.go
+++ b/cmd/nfd-topology-updater/main.go
@@ -112,12 +112,13 @@ func parseArgs(flags *flag.FlagSet, osArgs ...string) (*topology.Args, *resource
 	}
 
 	if len(resourcemonitorArgs.KubeletConfigURI) == 0 {
-		if len(utils.NodeName()) == 0 {
-			fmt.Fprintf(flags.Output(), "unable to determine the default kubelet config endpoint 'https://${NODE_NAME}:%d/configz' due to empty NODE_NAME environment, "+
-				"please either define the NODE_NAME environment variable or specify endpoint with the -kubelet-config-uri flag\n", kubeletSecurePort)
+		nodeIP := os.Getenv("NODE_IP")
+		if len(nodeIP) == 0 {
+			fmt.Fprintf(flags.Output(), "unable to determine the default kubelet config endpoint 'https://${NODE_IP}:%d/configz' due to empty NODE_IP environment, "+
+				"please either define the NODE_IP environment variable or specify endpoint with the -kubelet-config-uri flag\n", kubeletSecurePort)
 			os.Exit(1)
 		}
-		resourcemonitorArgs.KubeletConfigURI = fmt.Sprintf("https://%s:%d/configz", utils.NodeName(), kubeletSecurePort)
+		resourcemonitorArgs.KubeletConfigURI = fmt.Sprintf("https://%s:%d/configz", nodeIP, kubeletSecurePort)
 	}
 
 	return args, resourcemonitorArgs
diff --git a/deployment/components/topology-updater/env.yaml b/deployment/components/topology-updater/env.yaml
new file mode 100644
index 0000000000..fbcc231776
--- /dev/null
+++ b/deployment/components/topology-updater/env.yaml
@@ -0,0 +1,7 @@
+- op: add
+  path: "/spec/template/spec/containers/0/env/-"
+  value:
+      name: NODE_IP
+      valueFrom:
+        fieldRef:
+          fieldPath: status.hostIP
diff --git a/deployment/components/topology-updater/kustomization.yaml b/deployment/components/topology-updater/kustomization.yaml
index b951ec605d..f025a7330f 100644
--- a/deployment/components/topology-updater/kustomization.yaml
+++ b/deployment/components/topology-updater/kustomization.yaml
@@ -14,3 +14,7 @@ patches:
   target:
     labelSelector: app=nfd
     name: nfd-topology-updater
+- path: env.yaml
+  target:
+    labelSelector: app=nfd
+    name: nfd-topology-updater
diff --git a/deployment/helm/node-feature-discovery/templates/topologyupdater.yaml b/deployment/helm/node-feature-discovery/templates/topologyupdater.yaml
index cd3fca051e..51285341eb 100644
--- a/deployment/helm/node-feature-discovery/templates/topologyupdater.yaml
+++ b/deployment/helm/node-feature-discovery/templates/topologyupdater.yaml
@@ -37,6 +37,10 @@ spec:
           valueFrom:
             fieldRef:
               fieldPath: spec.nodeName
+        - name: NODE_IP
+          valueFrom:
+            fieldRef:
+              fieldPath: status.hostIP
         command:
           - "nfd-topology-updater"
         args:
diff --git a/docs/reference/topology-updater-commandline-reference.md b/docs/reference/topology-updater-commandline-reference.md
index 4d35f917f3..47437ae33f 100644
--- a/docs/reference/topology-updater-commandline-reference.md
+++ b/docs/reference/topology-updater-commandline-reference.md
@@ -109,7 +109,7 @@ nfd-topology-updater -watch-namespace=rte
 The `-kubelet-config-uri` specifies the path to the Kubelet's configuration.
 Note that the URi could either be a local host file or an HTTP endpoint.
 
-Default:  `https://${NODE_NAME}:10250/configz`
+Default:  `https://${NODE_IP}:10250/configz`
 
 Example: