Clickhouse errors are marked as downstream errors for HTTP

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## (next)
+
+### Fixes
+
+- Improved error classification to mark all ClickHouse errors as downstream errors, including errors wrapped in HTTP response bodies and multi-error chains
+
 ## 4.11.1
 
 ### Fixes

pkg/plugin/driver.go

@@ -271,13 +271,49 @@ func (h *Clickhouse) Macros() sqlds.Macros {
 
 // MutateQueryError marks ClickHouse errors as downstream errors
 func (h *Clickhouse) MutateQueryError(err error) backend.ErrorWithSource {
-	var wrappedException *clickhouse.Exception
-	if errors.As(err, &wrappedException) {
+	// Check if any error in the error chain (including multi-errors) is a clickhouse.Exception
+	if containsClickHouseException(err) {
 		return backend.NewErrorWithSource(err, backend.ErrorSourceDownstream)
 	}
 	return backend.NewErrorWithSource(err, backend.DefaultErrorSource)
 }
 
+// containsClickHouseException checks if err or any error in its chain is a clickhouse.Exception
+// It also handles errors wrapped in HTTP response bodies
+func containsClickHouseException(err error) bool {
+	if err == nil {
+		return false
+	}
+
+	// Check if the current error is directly a clickhouse.Exception
+	var wrappedException *clickhouse.Exception
+	if errors.As(err, &wrappedException) {
+		return true
+	}
+
+	errStr := err.Error()
+
+	// Look for common ClickHouse error patterns in response bodies
+	if strings.Contains(errStr, "DB::Exception") {
+		return true
+	}
+
+	// Check for multiple wrapped errors (e.g., from errors.Join)
+	type multiError interface {
+		Unwrap() []error
+	}
+
+	if u, ok := err.(multiError); ok {
+		for _, e := range u.Unwrap() {
+			if containsClickHouseException(e) {
+				return true
+			}
+		}
+	}
+
+	return false
+}
+
 func (h *Clickhouse) Settings(ctx context.Context, config backend.DataSourceInstanceSettings) sqlds.DriverSettings {
 	settings, err := LoadSettings(ctx, config)
 	timeout := 60

pkg/plugin/driver_test.go

@@ -2,8 +2,11 @@ package plugin
 
 import (
 	"encoding/json"
+	"errors"
+	"fmt"
 	"testing"
 
+	"github.com/ClickHouse/clickhouse-go/v2"
 	"github.com/grafana/grafana-plugin-sdk-go/data"
 	"github.com/stretchr/testify/assert"
 )
@@ -257,3 +260,53 @@ func TestAssignFlattenedPath(t *testing.T) {
 		assert.Equal(t, expected, flatMap)
 	})
 }
+
+func TestContainsClickHouseException(t *testing.T) {
+	t.Run("nil error", func(t *testing.T) {
+		result := containsClickHouseException(nil)
+		assert.False(t, result)
+	})
+
+	t.Run("direct clickhouse exception", func(t *testing.T) {
+		chErr := &clickhouse.Exception{
+			Code:    60,
+			Message: "Unknown table",
+		}
+		result := containsClickHouseException(chErr)
+		assert.True(t, result)
+	})
+
+	t.Run("wrapped clickhouse exception", func(t *testing.T) {
+		chErr := &clickhouse.Exception{
+			Code:    62,
+			Message: "Syntax error",
+		}
+		wrappedErr := fmt.Errorf("query failed: %w", chErr)
+		result := containsClickHouseException(wrappedErr)
+		assert.True(t, result)
+	})
+
+	t.Run("HTTP response body with clickhouse error", func(t *testing.T) {
+		errMsg := `error querying the database: sendQuery: [HTTP 404] response body: \"Code: 60. DB::Exception: Unknown table expression identifier 'hello' in scope SELECT * FROM hello. (UNKNOWN_TABLE) (version 25.1.3.23 (official build))\n\"`
+		err := errors.New(errMsg)
+		result := containsClickHouseException(err)
+		assert.True(t, result)
+	})
+
+	t.Run("regular error without clickhouse patterns", func(t *testing.T) {
+		err := errors.New("connection timeout")
+		result := containsClickHouseException(err)
+		assert.False(t, result)
+	})
+
+	t.Run("multi-error with clickhouse exception", func(t *testing.T) {
+		chErr := &clickhouse.Exception{
+			Code:    60,
+			Message: "Unknown table",
+		}
+		regularErr := errors.New("regular error")
+		multiErr := errors.Join(regularErr, chErr)
+		result := containsClickHouseException(multiErr)
+		assert.True(t, result)
+	})
+}