[v13] use active db cert principals when available

tool/tsh/db.go

@@ -852,6 +852,23 @@ func newDatabaseInfo(cf *CLIConf, tc *client.TeleportClient, route *tlsca.RouteT
 // checkAndSetPrincipalDefaults checks the db route (schema) name and username,
 // and sets them to defaults if necessary.
 func (d *databaseInfo) checkAndSetPrincipalDefaults(cf *CLIConf, tc *client.TeleportClient, db types.Database) error {
+	profile, err := tc.ProfileStatus()
+	if err != nil {
+		return trace.Wrap(err)
+	}
+
+	// if either user or db name isn't given as a cli flag, try to populate
+	// user/db name from an active db cert.
+	if cf.DatabaseUser == "" || cf.DatabaseName == "" {
+		routes, err := profile.DatabasesForCluster(tc.SiteName)
+		if err != nil {
+			return trace.Wrap(err)
+		}
+		if route, ok := findActiveDatabase(d.ServiceName, routes); ok {
+			d.Username = route.Username
+			d.Database = route.Database
+		}
+	}
 	if cf.DatabaseUser != "" {
 		d.Username = cf.DatabaseUser
 	}
@@ -1228,16 +1245,11 @@ func filterActiveDatabases(ctx context.Context, tc *client.TeleportClient, activ
 	}
 	prefix := tc.DatabaseService
 	if len(tc.Labels) == 0 && tc.PredicateExpression == "" {
-		if prefix == "" && len(activeRoutes) == 1 {
-			return activeRoutes, nil, nil
-		}
 		// when we have a name but don't have label or predicate query, look for
 		// a route that matches the name exactly to maybe avoid calling
 		// ListDatabases API below.
-		for _, route := range activeRoutes {
-			if route.ServiceName == prefix {
-				return []tlsca.RouteToDatabase{route}, nil, nil
-			}
+		if route, ok := findActiveDatabase(prefix, activeRoutes); ok {
+			return []tlsca.RouteToDatabase{route}, nil, nil
 		}
 	}
 
@@ -1274,6 +1286,20 @@ func filterActiveDatabases(ctx context.Context, tc *client.TeleportClient, activ
 	return selectedRoutes, activeDBs, nil
 }
 
+// findActiveDatabase returns a database route and a bool indicating whether
+// the route was found.
+func findActiveDatabase(name string, activeRoutes []tlsca.RouteToDatabase) (tlsca.RouteToDatabase, bool) {
+	if name == "" && len(activeRoutes) == 1 {
+		return activeRoutes[0], true
+	}
+	for _, r := range activeRoutes {
+		if r.ServiceName == name {
+			return r, true
+		}
+	}
+	return tlsca.RouteToDatabase{}, false
+}
+
 func formatDatabaseListCommand(clusterFlag string) string {
 	if clusterFlag == "" {
 		return "tsh db ls"

tool/tsh/db_test.go

@@ -973,8 +973,11 @@ func testDatabaseInfo(t *testing.T) {
 	require.NoError(t, err)
 	defaultDBUser := "admin"
 	defaultDBName := "default"
-	alice.SetDatabaseUsers([]string{defaultDBUser})
-	alice.SetDatabaseNames([]string{defaultDBName})
+	// add multiple allowed db names/users, to prevent default selection.
+	// these tests should use the db name/username from either cli flag or
+	// active cert only.
+	alice.SetDatabaseUsers([]string{defaultDBUser, "foo"})
+	alice.SetDatabaseNames([]string{defaultDBName, "bar"})
 	alice.SetRoles([]string{"access"})
 	databases := []servicecfg.Database{
 		{
@@ -1050,7 +1053,7 @@ func testDatabaseInfo(t *testing.T) {
 				Database:    defaultDBName,
 			}
 			t.Run(route.ServiceName, func(t *testing.T) {
-				t.Run("with active db cert", func(t *testing.T) {
+				t.Run("with route", func(t *testing.T) {
 					cf := &CLIConf{
 						Context:         ctx,
 						TracingProvider: tracing.NoopProvider(),
@@ -1076,15 +1079,18 @@ func testDatabaseInfo(t *testing.T) {
 					require.Equal(t, route.Protocol, db.GetProtocol())
 					require.Equal(t, dbInfo.database, db, "database should have been fetched and cached")
 				})
-				t.Run("without active db cert", func(t *testing.T) {
+				t.Run("without route", func(t *testing.T) {
+					err = Run(ctx, []string{"db", "login", route.ServiceName,
+						"--db-user", route.Username,
+						"--db-name", route.Database,
+					}, setHomePath(tmpHomePath))
+					require.NoError(t, err)
 					cf := &CLIConf{
 						Context:         ctx,
 						TracingProvider: tracing.NoopProvider(),
 						HomePath:        tmpHomePath,
 						tracer:          tracing.NoopTracer(teleport.ComponentTSH),
 						DatabaseService: route.ServiceName,
-						DatabaseUser:    route.Username,
-						DatabaseName:    route.Database,
 					}
 					tc, err := makeClient(cf)
 					require.NoError(t, err)