feat(outputs.bigquery): Allow to add metrics in one compact table

plugins/outputs/bigquery/README.md

@@ -36,6 +36,9 @@ See the [CONFIGURATION.md][CONFIGURATION.md] for more details.
 
   ## Character to replace hyphens on Metric name
   # replace_hyphen_to = "_"
+
+  ## Write all metrics in a single compact table
+  # compact_table = ""
 ```
 
 Leaving `project` empty indicates the plugin will try to retrieve the project
@@ -54,6 +57,36 @@ table on BigQuery:
 * Should contain the metric's fields with the same name and the column type
   should match the field type.
 
+## Compact table
+
+When enabling the compact table, all metrics are inserted to the given table
+with the following schema:
+
+```json
+[
+  {
+    "mode": "REQUIRED",
+    "name": "timestamp",
+    "type": "TIMESTAMP"
+  },
+  {
+    "mode": "REQUIRED",
+    "name": "name",
+    "type": "STRING"
+  },
+  {
+    "mode": "REQUIRED",
+    "name": "tags",
+    "type": "JSON"
+  },
+  {
+    "mode": "REQUIRED",
+    "name": "fields",
+    "type": "JSON"
+  }
+]
+```
+
 ## Restrictions
 
 Avoid hyphens on BigQuery tables, underlying SDK cannot handle streaming inserts

plugins/outputs/bigquery/bigquery.go

@@ -4,6 +4,7 @@ package bigquery
 import (
 	"context"
 	_ "embed"
+	"encoding/json"
 	"errors"
 	"fmt"
 	"reflect"
@@ -34,6 +35,7 @@ type BigQuery struct {
 
 	Timeout         config.Duration `toml:"timeout"`
 	ReplaceHyphenTo string          `toml:"replace_hyphen_to"`
+	CompactTable    string          `toml:"compact_table"`
 
 	Log telegraf.Logger `toml:"-"`
 
@@ -62,9 +64,22 @@ func (s *BigQuery) Init() error {
 
 func (s *BigQuery) Connect() error {
 	if s.client == nil {
-		return s.setUpDefaultClient()
+		if err := s.setUpDefaultClient(); err != nil {
+			return err
+		}
 	}
 
+	if s.CompactTable != "" {
+		ctx := context.Background()
+		ctx, cancel := context.WithTimeout(ctx, time.Duration(s.Timeout))
+		defer cancel()
+
+		// Check if the compact table exists
+		_, err := s.client.DatasetInProject(s.Project, s.Dataset).Table(s.CompactTable).Metadata(ctx)
+		if err != nil {
+			return fmt.Errorf("compact table: %w", err)
+		}
+	}
 	return nil
 }
 
@@ -81,7 +96,7 @@ func (s *BigQuery) setUpDefaultClient() error {
 		creds, err := google.FindDefaultCredentials(ctx)
 		if err != nil {
 			return fmt.Errorf(
-				"unable to find Google Cloud Platform Application Default Credentials: %v. "+
+				"unable to find Google Cloud Platform Application Default Credentials: %w. "+
 					"Either set ADC or provide CredentialsFile config", err)
 		}
 		credentialsOption = option.WithCredentials(creds)
@@ -94,6 +109,10 @@ func (s *BigQuery) setUpDefaultClient() error {
 
 // Write the metrics to Google Cloud BigQuery.
 func (s *BigQuery) Write(metrics []telegraf.Metric) error {
+	if s.CompactTable != "" {
+		return s.writeCompact(metrics)
+	}
+
 	groupedMetrics := s.groupByMetricName(metrics)
 
 	var wg sync.WaitGroup
@@ -111,6 +130,26 @@ func (s *BigQuery) Write(metrics []telegraf.Metric) error {
 	return nil
 }
 
+func (s *BigQuery) writeCompact(metrics []telegraf.Metric) error {
+	ctx := context.Background()
+	ctx, cancel := context.WithTimeout(ctx, time.Duration(s.Timeout))
+	defer cancel()
+
+	// Always returns an instance, even if table doesn't exist (anymore).
+	inserter := s.client.DatasetInProject(s.Project, s.Dataset).Table(s.CompactTable).Inserter()
+
+	var compactValues []*bigquery.ValuesSaver
+	for _, m := range metrics {
+		valueSaver, err := s.newCompactValuesSaver(m)
+		if err != nil {
+			s.Log.Warnf("could not prepare metric as compact value: %v", err)
+		} else {
+			compactValues = append(compactValues, valueSaver)
+		}
+	}
+	return inserter.Put(ctx, compactValues)
+}
+
 func (s *BigQuery) groupByMetricName(metrics []telegraf.Metric) map[string][]bigquery.ValueSaver {
 	groupedMetrics := make(map[string][]bigquery.ValueSaver)
 
@@ -138,29 +177,63 @@ func newValuesSaver(m telegraf.Metric) *bigquery.ValuesSaver {
 	}
 }
 
+func (s *BigQuery) newCompactValuesSaver(m telegraf.Metric) (*bigquery.ValuesSaver, error) {
+	tags, err := json.Marshal(m.Tags())
+	if err != nil {
+		return nil, fmt.Errorf("serializing tags: %w", err)
+	}
+
+	fields, err := json.Marshal(m.Fields())
+	if err != nil {
+		return nil, fmt.Errorf("serializing fields: %w", err)
+	}
+
+	return &bigquery.ValuesSaver{
+		Schema: bigquery.Schema{
+			timeStampFieldSchema(),
+			newStringFieldSchema("name"),
+			newJSONFieldSchema("tags"),
+			newJSONFieldSchema("fields"),
+		},
+		Row: []bigquery.Value{
+			m.Time(),
+			m.Name(),
+			string(tags),
+			string(fields),
+		},
+	}, nil
+}
+
 func timeStampFieldSchema() *bigquery.FieldSchema {
 	return &bigquery.FieldSchema{
 		Name: timeStampFieldName,
 		Type: bigquery.TimestampFieldType,
 	}
 }
 
+func newStringFieldSchema(name string) *bigquery.FieldSchema {
+	return &bigquery.FieldSchema{
+		Name: name,
+		Type: bigquery.StringFieldType,
+	}
+}
+
+func newJSONFieldSchema(name string) *bigquery.FieldSchema {
+	return &bigquery.FieldSchema{
+		Name: name,
+		Type: bigquery.JSONFieldType,
+	}
+}
+
 func tagsSchemaAndValues(m telegraf.Metric, s bigquery.Schema, r []bigquery.Value) ([]*bigquery.FieldSchema, []bigquery.Value) {
 	for _, t := range m.TagList() {
-		s = append(s, tagFieldSchema(t))
+		s = append(s, newStringFieldSchema(t.Key))
 		r = append(r, t.Value)
 	}
 
 	return s, r
 }
 
-func tagFieldSchema(t *telegraf.Tag) *bigquery.FieldSchema {
-	return &bigquery.FieldSchema{
-		Name: t.Key,
-		Type: bigquery.StringFieldType,
-	}
-}
-
 func valuesSchemaAndValues(m telegraf.Metric, s bigquery.Schema, r []bigquery.Value) ([]*bigquery.FieldSchema, []bigquery.Value) {
 	for _, f := range m.FieldList() {
 		s = append(s, valuesSchema(f))

plugins/outputs/bigquery/bigquery_test.go

@@ -107,15 +107,42 @@ func TestConnect(t *testing.T) {
 	srv := localBigQueryServer(t)
 	defer srv.Close()
 
-	b := &BigQuery{
-		Project: "test-project",
-		Dataset: "test-dataset",
-		Timeout: defaultTimeout,
+	tests := []struct {
+		name         string
+		compactTable string
+		errorString  string
+	}{
+		{name: "normal"},
+		{
+			name:         "compact table existing",
+			compactTable: "test-metrics",
+		},
+		{
+			name:         "compact table not existing",
+			compactTable: "foobar",
+			errorString:  "compact table: googleapi: got HTTP response code 404",
+		},
 	}
 
-	require.NoError(t, b.Init())
-	require.NoError(t, b.setUpTestClient(srv.URL))
-	require.NoError(t, b.Connect())
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			b := &BigQuery{
+				Project:      "test-project",
+				Dataset:      "test-dataset",
+				Timeout:      defaultTimeout,
+				CompactTable: tt.compactTable,
+			}
+
+			require.NoError(t, b.Init())
+			require.NoError(t, b.setUpTestClient(srv.URL))
+
+			if tt.errorString != "" {
+				require.ErrorContains(t, b.Connect(), tt.errorString)
+			} else {
+				require.NoError(t, b.Connect())
+			}
+		})
+	}
 }
 
 func TestWrite(t *testing.T) {
@@ -148,6 +175,42 @@ func TestWrite(t *testing.T) {
 	require.Equal(t, mockMetrics[0].Fields()["value"], row.Value)
 }
 
+func TestWriteCompact(t *testing.T) {
+	srv := localBigQueryServer(t)
+	defer srv.Close()
+
+	b := &BigQuery{
+		Project:      "test-project",
+		Dataset:      "test-dataset",
+		Timeout:      defaultTimeout,
+		CompactTable: "test-metrics",
+	}
+
+	mockMetrics := testutil.MockMetrics()
+
+	require.NoError(t, b.Init())
+	require.NoError(t, b.setUpTestClient(srv.URL))
+	require.NoError(t, b.Connect())
+
+	require.NoError(t, b.Write(mockMetrics))
+
+	var rows []map[string]json.RawMessage
+	require.NoError(t, json.Unmarshal(receivedBody["rows"], &rows))
+	require.Len(t, rows, 1)
+	require.Contains(t, rows[0], "json")
+
+	var row interface{}
+	require.NoError(t, json.Unmarshal(rows[0]["json"], &row))
+	require.Equal(t, map[string]interface{}{
+		"timestamp": "2009-11-10T23:00:00Z",
+		"name":      "test1",
+		"tags":      `{"tag1":"value1"}`,
+		"fields":    `{"value":1}`,
+	}, row)
+
+	require.NoError(t, b.Close())
+}
+
 func (b *BigQuery) setUpTestClient(endpointURL string) error {
 	noAuth := option.WithoutAuthentication()
 	endpoint := option.WithEndpoint(endpointURL)
@@ -170,15 +233,22 @@ func localBigQueryServer(t *testing.T) *httptest.Server {
 
 	srv.Config.Handler = http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		switch r.URL.Path {
-		case "/projects/test-project/datasets/test-dataset/tables/test1/insertAll":
+		case "/projects/test-project/datasets/test-dataset/tables/test1/insertAll",
+			"/projects/test-project/datasets/test-dataset/tables/test-metrics/insertAll":
 			decoder := json.NewDecoder(r.Body)
 			require.NoError(t, decoder.Decode(&receivedBody))
 
 			w.WriteHeader(http.StatusOK)
 			_, err := w.Write([]byte(successfulResponse))
 			require.NoError(t, err)
+		case "/projects/test-project/datasets/test-dataset/tables/test-metrics":
+			w.WriteHeader(http.StatusOK)
+			_, err := w.Write([]byte("{}"))
+			require.NoError(t, err)
 		default:
 			w.WriteHeader(http.StatusNotFound)
+			_, err := w.Write([]byte(r.URL.String()))
+			require.NoError(t, err)
 		}
 	})
 

plugins/outputs/bigquery/sample.conf

@@ -14,3 +14,6 @@
 
   ## Character to replace hyphens on Metric name
   # replace_hyphen_to = "_"
+
+  ## Write all metrics in a single compact table
+  # compact_table = ""