Fix handling of net.IP during node merge

Because net.IP is derived from []byte, it was being handled by mergo as a
slice. This adds an additional transformer that handles net.IP specifically,
and also watches for this type in field tracking.

Signed-off-by: Jonathon Anderson <janderson@ciq.com>

internal/pkg/node/mergo.go

@@ -1,6 +1,7 @@
 package node
 
 import (
+	"net"
 	"reflect"
 	"strings"
 
@@ -58,10 +59,18 @@ func (config *NodesYaml) appendProfileProfiles(profiles []string, id string) []s
 	return profiles
 }
 
-type InterfaceTransformer struct{}
+type Transformer struct{}
 
-func (t InterfaceTransformer) Transformer(typ reflect.Type) func(dst, src reflect.Value) error {
-	if typ.Kind() == reflect.Interface {
+func (t Transformer) Transformer(typ reflect.Type) func(dst, src reflect.Value) error {
+	if typ == reflect.TypeOf(net.IP{}) {
+		return func(dst, src reflect.Value) error {
+			if !src.IsValid() || !src.CanSet() {
+				return nil
+			}
+			dst.Set(src)
+			return nil
+		}
+	} else if typ.Kind() == reflect.Interface {
 		return func(dst, src reflect.Value) error {
 			if !src.IsValid() || src.IsZero() {
 				return nil
@@ -159,7 +168,7 @@ func (config *NodesYaml) MergeNode(id string) (node Node, fields fieldMap, err e
 //
 // Returns an error if the merging operation fails.
 func merge(dest, src interface{}, fields fieldMap, srcName string, multipleSrcName string) error {
-	if err := mergo.Merge(dest, src, mergo.WithAppendSlice, mergo.WithOverride, mergo.WithTransformers(InterfaceTransformer{})); err != nil {
+	if err := mergo.Merge(dest, src, mergo.WithAppendSlice, mergo.WithOverride, mergo.WithTransformers(Transformer{})); err != nil {
 		return err
 	}
 
@@ -170,7 +179,9 @@ func merge(dest, src interface{}, fields fieldMap, srcName string, multipleSrcNa
 			if prevSource != "" {
 				switch value.Kind() {
 				case reflect.Slice:
-					srcName = strings.Join([]string{prevSource, multipleSrcName}, ",")
+					if value.Type() != reflect.TypeOf(net.IP{}) {
+						srcName = strings.Join([]string{prevSource, multipleSrcName}, ",")
+					}
 				case reflect.Interface:
 					if _, ok := value.Interface().([]interface{}); ok {
 						srcName = strings.Join([]string{prevSource, multipleSrcName}, ",")

internal/pkg/node/mergo_test.go

@@ -1,6 +1,8 @@
 package node
 
 import (
+	"fmt"
+	"net"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -823,6 +825,128 @@ nodes:
 	}
 }
 
+func Test_MergeNodeIP(t *testing.T) {
+	tests := map[string]struct {
+		nodesConf string
+		node      string
+		netdev    string
+		ipaddr    net.IP
+		ipaddrStr string
+		source    string
+	}{
+		"empty": {
+			nodesConf: `
+nodes:
+  n1:
+    network devices:
+      default: {}
+`,
+			node:      "n1",
+			netdev:    "default",
+			ipaddr:    nil,
+			ipaddrStr: "",
+			source:    "",
+		},
+		"single node value": {
+			nodesConf: `
+nodes:
+  n1:
+    network devices:
+      default:
+        ipaddr: 192.168.0.1
+`,
+			node:      "n1",
+			netdev:    "default",
+			ipaddr:    net.IPv4(192, 168, 0, 1),
+			ipaddrStr: "192.168.0.1",
+			source:    "",
+		},
+		"profile value": {
+			nodesConf: `
+nodeprofiles:
+  p1:
+    network devices:
+      default:
+        ipaddr: 192.168.0.1
+nodes:
+  n1:
+    profiles:
+    - p1
+`,
+			node:      "n1",
+			netdev:    "default",
+			ipaddr:    net.IPv4(192, 168, 0, 1),
+			ipaddrStr: "192.168.0.1",
+			source:    "p1",
+		},
+		"multi-profile value": {
+			nodesConf: `
+nodeprofiles:
+  p1:
+    network devices:
+      default:
+        ipaddr: 192.168.0.1
+  p2:
+    network devices:
+      default:
+        ipaddr: 192.168.1.1
+nodes:
+  n1:
+    profiles:
+    - p1
+    - p2
+`,
+			node:      "n1",
+			netdev:    "default",
+			ipaddr:    net.IPv4(192, 168, 1, 1),
+			ipaddrStr: "192.168.1.1",
+			source:    "p2",
+		},
+		"superseded": {
+			nodesConf: `
+nodeprofiles:
+  p1:
+    network devices:
+      default:
+        ipaddr: 192.168.0.1
+  p2:
+    network devices:
+      default:
+        ipaddr: 192.168.1.1
+nodes:
+  n1:
+    profiles:
+    - p1
+    - p2
+    network devices:
+      default:
+        ipaddr: 192.168.2.1
+`,
+			node:      "n1",
+			netdev:    "default",
+			ipaddr:    net.IPv4(192, 168, 2, 1),
+			ipaddrStr: "192.168.2.1",
+			source:    "SUPERSEDED",
+		},
+	}
+
+	for name, tt := range tests {
+		t.Run(name, func(t *testing.T) {
+			env := testenv.New(t)
+			defer env.RemoveAll()
+			env.WriteFile("/etc/warewulf/nodes.conf", tt.nodesConf)
+
+			registry, regErr := New()
+			assert.NoError(t, regErr)
+			node, fields, mergeErr := registry.MergeNode(tt.node)
+			assert.NoError(t, mergeErr)
+			assert.Equal(t, tt.ipaddr, node.NetDevs[tt.netdev].Ipaddr)
+			assert.Equal(t, tt.ipaddrStr, fields.Value(fmt.Sprintf("NetDevs[%s].Ipaddr", tt.netdev)))
+			assert.Equal(t, tt.source, fields.Source(fmt.Sprintf("NetDevs[%s].Ipaddr", tt.netdev)))
+		})
+	}
+}
+
 func Test_MergeNodeKernel(t *testing.T) {
 	var tests = map[string]struct {
 		nodesConf string