Add support to get connection data from Trigger Authorization in PostgreSQL Scaler

CHANGELOG.md

@@ -38,6 +38,7 @@
 - Add support to get connection data from Trigger Authorization in MongoDB Scaler ([#2115](https://github.com/kedacore/keda/pull/2115))
 - Add support to get connection data from Trigger Authorization in MySQL Scaler ([#2113](https://github.com/kedacore/keda/pull/2113))
 - Add support to get connection data from Trigger Authorization in MSSQL Scaler ([#2112](https://github.com/kedacore/keda/pull/2112))
+- Add support to get connection data from Trigger Authorization in PostgreSQL Scaler ([#2114](https://github.com/kedacore/keda/pull/2114))
 - Add support to provide the metric name in Azure Log Analytics Scaler ([#2106](https://github.com/kedacore/keda/pull/2106))
 
 ### Breaking Changes

pkg/scalers/postgresql_scaler.go

@@ -81,31 +81,30 @@ func parsePostgreSQLMetadata(config *ScalerConfig) (*postgreSQLMetadata, error)
 		meta.connection = config.ResolvedEnv[config.TriggerMetadata["connectionFromEnv"]]
 	default:
 		meta.connection = ""
-		if val, ok := config.TriggerMetadata["host"]; ok {
-			meta.host = val
-		} else {
-			return nil, fmt.Errorf("no  host given")
+		var err error
+		meta.host, err = getFromAuthOrMeta(config, "host")
+		if err != nil {
+			return nil, err
 		}
-		if val, ok := config.TriggerMetadata["port"]; ok {
-			meta.port = val
-		} else {
-			return nil, fmt.Errorf("no  port given")
+
+		meta.port, err = getFromAuthOrMeta(config, "port")
+		if err != nil {
+			return nil, err
 		}
 
-		if val, ok := config.TriggerMetadata["userName"]; ok {
-			meta.userName = val
-		} else {
-			return nil, fmt.Errorf("no  username given")
+		meta.port, err = getFromAuthOrMeta(config, "userName")
+		if err != nil {
+			return nil, err
 		}
-		if val, ok := config.TriggerMetadata["dbName"]; ok {
-			meta.dbName = val
-		} else {
-			return nil, fmt.Errorf("no dbname given")
+
+		meta.dbName, err = getFromAuthOrMeta(config, "dbName")
+		if err != nil {
+			return nil, err
 		}
-		if val, ok := config.TriggerMetadata["sslmode"]; ok {
-			meta.sslmode = val
-		} else {
-			return nil, fmt.Errorf("no sslmode name given")
+
+		meta.sslmode, err = getFromAuthOrMeta(config, "sslmode")
+		if err != nil {
+			return nil, err
 		}
 
 		if config.AuthParams["password"] != "" {
@@ -225,3 +224,17 @@ func (s *postgreSQLScaler) GetMetrics(ctx context.Context, metricName string, me
 
 	return append([]external_metrics.ExternalMetricValue{}, metric), nil
 }
+
+func getFromAuthOrMeta(config *ScalerConfig, field string) (string, error) {
+	var result string
+	var err error
+	if config.AuthParams[field] != "" {
+		result = config.AuthParams[field]
+	} else if config.TriggerMetadata[field] != "" {
+		result = config.TriggerMetadata[field]
+	}
+	if result == "" {
+		err = fmt.Errorf("no %s given", field)
+	}
+	return result, err
+}

pkg/scalers/postgresql_scaler_test.go

@@ -54,3 +54,58 @@ func TestPosgresSQLGetMetricSpecForScaling(t *testing.T) {
 		}
 	}
 }
+
+var testPostgresResolvedEnv = map[string]string{
+	"POSTGRE_PASSWORD": "pass",
+	"POSTGRE_CONN_STR": "test_conn_str",
+}
+
+type parsePostgresMetadataTestData struct {
+	metadata    map[string]string
+	authParams  map[string]string
+	resolvedEnv map[string]string
+	raisesError bool
+}
+
+var testPostgresMetadata = []parsePostgresMetadataTestData{
+	// No metadata
+	{
+		metadata:    map[string]string{},
+		authParams:  map[string]string{},
+		resolvedEnv: map[string]string{},
+		raisesError: true,
+	},
+	// connectionString
+	{
+		metadata:    map[string]string{"query": "query", "targetQueryValue": "12", "connectionFromEnv": "POSTGRE_CONN_STR"},
+		authParams:  map[string]string{},
+		resolvedEnv: testPostgresResolvedEnv,
+		raisesError: false,
+	},
+	// Params instead of conn str
+	{
+		metadata:    map[string]string{"query": "query", "targetQueryValue": "12", "host": "test_host", "port": "test_port", "userName": "test_username", "passwordFromEnv": "POSTGRE_PASSWORD", "dbName": "test_dbname", "sslmode": "require"},
+		authParams:  map[string]string{},
+		resolvedEnv: testPostgresResolvedEnv,
+		raisesError: false,
+	},
+	// Params from trigger authentication
+	{
+		metadata:    map[string]string{"query": "query", "targetQueryValue": "12"},
+		authParams:  map[string]string{"host": "test_host", "port": "test_port", "userName": "test_username", "password": "POSTGRE_PASSWORD", "dbName": "test_dbname", "sslmode": "disable"},
+		resolvedEnv: testPostgresResolvedEnv,
+		raisesError: false,
+	},
+}
+
+func TestParsePosgresSQLMetadata(t *testing.T) {
+	for _, testData := range testPostgresMetadata {
+		_, err := parsePostgreSQLMetadata(&ScalerConfig{ResolvedEnv: testData.resolvedEnv, TriggerMetadata: testData.metadata, AuthParams: testData.authParams})
+		if err != nil && !testData.raisesError {
+			t.Error("Expected success but got error", err)
+		}
+		if err == nil && testData.raisesError {
+			t.Error("Expected error but got success")
+		}
+	}
+}