Permit routing to agentless nodes with non-UUID metadata.name (#50915)

We suggest that a UUID is used for agentless nodes metadata.name
field, but we do not enforce it. This causes several edge cases
and slightly weird UX in places that expect the name to be a UUID.
Most notably, this presents dialing problems for the web ui as
described in https://github.com/gravitational/teleport/issues/50914.
To allowing dialing to function in all cases for these servers,
routing has been updated to permit matches on metadata.name, however,
the match is given a lower score then a match on a UUID. This should
permit dialing, though, it may still result in ambiguity.

Closes #50914.

api/utils/route.go

@@ -180,6 +180,14 @@ func (m *SSHRouteMatcher) RouteToServerScore(server RouteableServer) (score int)
 		score = max(score, matchAddr(addr))
 	}
 
+	// Allow a match on name, even though it may not be a UUID or EC2 ID,
+	// to support agentless hosts that were created without their name being a UUID.
+	// The score however, is lower than a true direct match, to prevent any
+	// breaking changes to routing.
+	if server.GetName() == m.cfg.Host {
+		score = max(score, indirectMatch)
+	}
+
 	return score
 }
 

api/utils/route_test.go

@@ -15,6 +15,7 @@
 package utils
 
 import (
+	"cmp"
 	"context"
 	"testing"
 
@@ -273,6 +274,7 @@ func TestSSHRouteMatcherScoring(t *testing.T) {
 	tts := []struct {
 		desc     string
 		hostname string
+		name     string
 		addrs    []string
 		score    int
 	}{
@@ -309,12 +311,23 @@ func TestSSHRouteMatcherScoring(t *testing.T) {
 			},
 			score: notMatch,
 		},
+		{
+			desc:     "non-uuid name",
+			name:     "foo.example.com",
+			hostname: "foo.com",
+			addrs: []string{
+				"0.0.0.0:0",
+				"1.1.1.1:0",
+			},
+			score: indirectMatch,
+		},
 	}
 
 	for _, tt := range tts {
 		t.Run(tt.desc, func(t *testing.T) {
+			name := cmp.Or(tt.name, uuid.NewString())
 			score := matcher.RouteToServerScore(mockRouteableServer{
-				name:       uuid.NewString(),
+				name:       name,
 				hostname:   tt.hostname,
 				publicAddr: tt.addrs,
 			})

lib/proxy/router_test.go

@@ -133,6 +133,11 @@ func TestRouteScoring(t *testing.T) {
 			hostname: "blue.example.com",
 			addr:     "2.3.4.5:22",
 		},
+		{
+			name:     "not-a-uuid",
+			hostname: "test.example.com",
+			addr:     "3.4.5.6:22",
+		},
 	})
 
 	// scoring behavior is independent of routing strategy so we just
@@ -205,6 +210,11 @@ func TestRouteScoring(t *testing.T) {
 			host:   "red.example.com",
 			expect: "blue.example.com",
 		},
+		{
+			desc:   "non-uuid name",
+			host:   "not-a-uuid",
+			expect: "test.example.com",
+		},
 	}
 
 	for _, tt := range tts {
@@ -326,6 +336,21 @@ func TestGetServers(t *testing.T) {
 		},
 	})
 
+	servers = append(servers,
+		&types.ServerV2{
+			Kind:    types.KindNode,
+			SubKind: types.SubKindOpenSSHNode,
+			Version: types.V2,
+			Metadata: types.Metadata{
+				Name: "agentless-node-1",
+			},
+			Spec: types.ServerSpecV2{
+				Addr:     "1.2.3.4:22",
+				Hostname: "agentless-1",
+			},
+		},
+	)
+
 	// ensure tests don't have order-dependence
 	rand.Shuffle(len(servers), func(i, j int) {
 		servers[i], servers[j] = servers[j], servers[i]
@@ -432,15 +457,6 @@ func TestGetServers(t *testing.T) {
 				require.Equal(t, "alpaca", srv.GetHostname())
 			},
 		},
-		{
-			name:         "failure on invalid addresses",
-			site:         testSite{cfg: &unambiguousCfg, nodes: servers},
-			host:         "lion",
-			errAssertion: require.NoError,
-			serverAssertion: func(t *testing.T, srv types.Server) {
-				require.Empty(t, srv)
-			},
-		},
 		{
 			name:         "case-insensitive match",
 			site:         testSite{cfg: &unambiguousInsensitiveCfg, nodes: servers},
@@ -462,6 +478,17 @@ func TestGetServers(t *testing.T) {
 				require.Empty(t, srv)
 			},
 		},
+		{
+			name:         "agentless match by non-uuid name",
+			site:         testSite{cfg: &unambiguousCfg, nodes: servers},
+			host:         "agentless-node-1",
+			errAssertion: require.NoError,
+			serverAssertion: func(t *testing.T, srv types.Server) {
+				require.NotNil(t, srv)
+				require.Equal(t, "agentless-1", srv.GetHostname())
+				require.True(t, srv.IsOpenSSHNode())
+			},
+		},
 	}
 
 	ctx := context.Background()
@@ -625,7 +652,7 @@ func TestRouter_DialHost(t *testing.T) {
 		SubKind: types.SubKindOpenSSHNode,
 		Version: types.V2,
 		Metadata: types.Metadata{
-			Name: uuid.NewString(),
+			Name: "agentless",
 		},
 		Spec: types.ServerSpecV2{
 			Addr:     "127.0.0.1:9001",