Extract AdminState type and fix lint issues

Signed-off-by: Vasyl Paliuha <vasyl.paliuha@sap.com>

Author: ObuMan

internal/provider/nokia/srlinux/admin.go

@@ -0,0 +1,11 @@
+// SPDX-FileCopyrightText: SAP SE or an SAP affiliate company and IronCore contributors
+// SPDX-License-Identifier: Apache-2.0
+
+package srlinux
+
+type AdminSt string
+
+const (
+	AdminStEnable  AdminSt = "enable"
+	AdminStDisable AdminSt = "disable"
+)

internal/provider/nokia/srlinux/dhcprelay.go

@@ -18,11 +18,6 @@ const (
 	// dhcpRelayDefaultSubinterfaceIndex is the subinterface a relay attaches to
 	// when the interface name carries no ".<index>" suffix.
 	dhcpRelayDefaultSubinterfaceIndex = 0
-
-	// dhcpRelayAdminStateEnable is the admin-state value that enables the relay.
-	// It is also the platform default, so it must be set explicitly to avoid a
-	// false diff against the device on every reconcile.
-	dhcpRelayAdminStateEnable = "enable"
 )
 
 var _ provider.DHCPRelayProvider = (*Provider)(nil)
@@ -62,7 +57,7 @@ func (p *Provider) EnsureDHCPRelay(ctx context.Context, req *provider.DHCPRelayR
 		sb.Update(&DHCPRelay{
 			Interface:         name,
 			SubinterfaceIndex: index,
-			AdminState:        dhcpRelayAdminStateEnable,
+			AdminState:        AdminStEnable,
 			Server:            req.DHCPRelay.Spec.Servers,
 			NetworkInstance:   networkInstance,
 		})
@@ -75,21 +70,21 @@ func (p *Provider) EnsureDHCPRelay(ctx context.Context, req *provider.DHCPRelayR
 // subinterface index. SRLinux names a subinterface "<interface>.<index>";
 // without a suffix the relay attaches to the base subinterface.
 func splitSubinterface(name string) (string, int, error) {
-	i := strings.LastIndex(name, ".")
-	if i == -1 {
+	base, suffix, found := strings.CutLast(name, ".")
+	if !found {
 		return name, dhcpRelayDefaultSubinterfaceIndex, nil
 	}
-	index, err := strconv.Atoi(name[i+1:])
+	index, err := strconv.Atoi(suffix)
 	if err != nil {
 		return "", 0, fmt.Errorf("invalid subinterface index in interface name %q: %w", name, err)
 	}
-	return name[:i], index, nil
+	return base, index, nil
 }
 
 type DHCPRelay struct {
 	Interface         string   `json:"-"`
 	SubinterfaceIndex int      `json:"-"`
-	AdminState        string   `json:"admin-state,omitempty"`
+	AdminState        AdminSt  `json:"admin-state,omitempty"`
 	Server            []string `json:"server,omitempty"`
 	NetworkInstance   string   `json:"network-instance,omitempty"`
 }

internal/provider/nokia/srlinux/dhcprelay_test.go

@@ -88,12 +88,12 @@ func TestDHCPRelayJSONNetworkInstance(t *testing.T) {
 	}{
 		{
 			name:    "empty network-instance is omitted",
-			relay:   &DHCPRelay{AdminState: dhcpRelayAdminStateEnable, Server: []string{"192.0.2.1"}},
+			relay:   &DHCPRelay{AdminState: AdminStEnable, Server: []string{"192.0.2.1"}},
 			wantKey: false,
 		},
 		{
 			name:    "set network-instance is present",
-			relay:   &DHCPRelay{AdminState: dhcpRelayAdminStateEnable, Server: []string{"192.0.2.1"}, NetworkInstance: "shared-services"},
+			relay:   &DHCPRelay{AdminState: AdminStEnable, Server: []string{"192.0.2.1"}, NetworkInstance: "shared-services"},
 			wantKey: true,
 		},
 	}
@@ -225,7 +225,7 @@ func TestDeleteDHCPRelay(t *testing.T) {
 		err := p.DeleteDHCPRelay(t.Context(), &provider.DeleteDHCPRelayRequest{
 			DHCPRelay: &corev1alpha1.DHCPRelay{
 				Spec: corev1alpha1.DHCPRelaySpec{
-					InterfaceRefs: []corev1alpha1.LocalObjectReference{{Name: "eth1"}},
+					InterfaceRefs: []corev1alpha1.LocalObjectReference{{Name: "eth1"}}, //nolint:staticcheck
 				},
 			},
 		})