tailcfg: add Node.Tags

Signed-off-by: Maisem Ali <maisem@tailscale.com>

tailcfg/tailcfg.go

@@ -164,6 +164,15 @@ type Node struct {
 	Hostinfo   Hostinfo
 	Created    time.Time
 
+	// Tags are the list of ACL tags applied to this node.
+	// Tags take the form of `tag:<value>` where value starts
+	// with a letter and only contains alphanumerics and dashes `-`.
+	// Some valid tag examples:
+	//   `tag:prod`
+	//   `tag:database`
+	//   `tag:lab-1`
+	Tags []string `json:",omitempty"`
+
 	// PrimaryRoutes are the routes from AllowedIPs that this node
 	// is currently the primary subnet router for, as determined
 	// by the control plane. It does not include the self address
@@ -1172,7 +1181,8 @@ func (n *Node) Equal(n2 *Node) bool {
 		eqStrings(n.Capabilities, n2.Capabilities) &&
 		n.ComputedName == n2.ComputedName &&
 		n.computedHostIfDifferent == n2.computedHostIfDifferent &&
-		n.ComputedNameWithHost == n2.ComputedNameWithHost
+		n.ComputedNameWithHost == n2.ComputedNameWithHost &&
+		eqStrings(n.Tags, n2.Tags)
 }
 
 func eqBoolPtr(a, b *bool) bool {

tailcfg/tailcfg_clone.go

@@ -51,6 +51,7 @@ func (src *Node) Clone() *Node {
 	dst.AllowedIPs = append(src.AllowedIPs[:0:0], src.AllowedIPs...)
 	dst.Endpoints = append(src.Endpoints[:0:0], src.Endpoints...)
 	dst.Hostinfo = *src.Hostinfo.Clone()
+	dst.Tags = append(src.Tags[:0:0], src.Tags...)
 	dst.PrimaryRoutes = append(src.PrimaryRoutes[:0:0], src.PrimaryRoutes...)
 	if dst.LastSeen != nil {
 		dst.LastSeen = new(time.Time)
@@ -81,6 +82,7 @@ var _NodeCloneNeedsRegeneration = Node(struct {
 	DERP                    string
 	Hostinfo                Hostinfo
 	Created                 time.Time
+	Tags                    []string
 	PrimaryRoutes           []netaddr.IPPrefix
 	LastSeen                *time.Time
 	Online                  *bool

tailcfg/tailcfg_test.go

@@ -195,7 +195,7 @@ func TestNodeEqual(t *testing.T) {
 		"ID", "StableID", "Name", "User", "Sharer",
 		"Key", "KeyExpiry", "Machine", "DiscoKey",
 		"Addresses", "AllowedIPs", "Endpoints", "DERP", "Hostinfo",
-		"Created", "PrimaryRoutes",
+		"Created", "Tags", "PrimaryRoutes",
 		"LastSeen", "Online", "KeepAlive", "MachineAuthorized",
 		"Capabilities",
 		"ComputedName", "computedHostIfDifferent", "ComputedNameWithHost",
@@ -366,6 +366,26 @@ func TestNodeEqual(t *testing.T) {
 			&Node{DERP: "bar"},
 			false,
 		},
+		{
+			&Node{Tags: []string{"tag:foo"}},
+			&Node{Tags: []string{"tag:foo"}},
+			true,
+		},
+		{
+			&Node{Tags: []string{"tag:foo", "tag:bar"}},
+			&Node{Tags: []string{"tag:bar"}},
+			false,
+		},
+		{
+			&Node{Tags: []string{"tag:foo"}},
+			&Node{Tags: []string{"tag:bar"}},
+			false,
+		},
+		{
+			&Node{Tags: []string{"tag:foo"}},
+			&Node{},
+			false,
+		},
 	}
 	for i, tt := range tests {
 		got := tt.a.Equal(tt.b)