feat(parsers.csv): add option for overwrite tags (#12008)

plugins/parsers/csv/README.md

@@ -73,6 +73,9 @@ values.
   ## will be added as fields.
   csv_tag_columns = []
 
+  ## Set to true to let the column tags overwrite the metadata and default tags.
+  csv_tag_overwrite = false
+
   ## The column to extract the name of the metric from. Will not be
   ## included as field in metric.
   csv_measurement_column = ""
@@ -167,7 +170,7 @@ Config:
   csv_metadata_separators = [":", "="]
   csv_metadata_trim_set = " #"
   csv_header_row_count = 1
-  csv_tag_columns = ["Version","File Created"]
+  csv_tag_columns = ["Version","cpu"]
   csv_timestamp_column = "time"
   csv_timestamp_format = "2006-01-02T15:04:05Z07:00"
 ```
@@ -177,14 +180,46 @@ Input:
 ```csv
 # Version=1.1
 # File Created: 2021-11-17T07:02:45+10:00
-measurement,cpu,time_user,time_system,time_idle,time
+Version,measurement,cpu,time_user,time_system,time_idle,time
-cpu,cpu0,42,42,42,2018-09-13T13:03:28Z
+1.2,cpu,cpu0,42,42,42,2018-09-13T13:03:28Z
 ```
 
 Output:
 
 ```text
-cpu,File\ Created=2021-11-17T07:02:45+10:00,Version=1.1 cpu=cpu0,time_user=42,time_system=42,time_idle=42 1536869008000000000
+cpu,cpu=cpu0,File\ Created=2021-11-17T07:02:45+10:00,Version=1.1 time_user=42,time_system=42,time_idle=42 1536869008000000000
 ```
 
+Config:
+
+```toml
+[[inputs.file]]
+  files = ["example"]
+  data_format = "csv"
+  csv_metadata_rows = 2
+  csv_metadata_separators = [":", "="]
+  csv_metadata_trim_set = " #"
+  csv_header_row_count = 1
+  csv_tag_columns = ["Version","cpu"]
+  csv_tag_overwrite = true
+  csv_timestamp_column = "time"
+  csv_timestamp_format = "2006-01-02T15:04:05Z07:00"
+```
+
+Input:
+
+```csv
+# Version=1.1
+# File Created: 2021-11-17T07:02:45+10:00
+Version,measurement,cpu,time_user,time_system,time_idle,time
+1.2,cpu,cpu0,42,42,42,2018-09-13T13:03:28Z
+```
+
+Output:
+
+```text
+cpu,cpu=cpu0,File\ Created=2021-11-17T07:02:45+10:00,Version=1.2 time_user=42,time_system=42,time_idle=42 1536869008000000000
+```
+
+[time parse]: https://pkg.go.dev/time#Parse
 [metric filtering]: /docs/CONFIGURATION.md#metric-filtering

plugins/parsers/csv/parser.go

@@ -34,6 +34,7 @@ type Parser struct {
 	SkipColumns        int             `toml:"csv_skip_columns"`
 	SkipRows           int             `toml:"csv_skip_rows"`
 	TagColumns         []string        `toml:"csv_tag_columns"`
+	TagOverwrite       bool            `toml:"csv_tag_overwrite"`
 	TimestampColumn    string          `toml:"csv_timestamp_column"`
 	TimestampFormat    string          `toml:"csv_timestamp_format"`
 	Timezone           string          `toml:"csv_timezone"`
@@ -314,6 +315,18 @@ func (p *Parser) parseRecord(record []string) (telegraf.Metric, error) {
 	recordFields := make(map[string]interface{})
 	tags := make(map[string]string)
 
+	if p.TagOverwrite {
+		// add default tags
+		for k, v := range p.DefaultTags {
+			tags[k] = v
+		}
+
+		// add metadata tags
+		for k, v := range p.metadataTags {
+			tags[k] = v
+		}
+	}
+
 	// skip columns in record
 	record = record[p.SkipColumns:]
 outer:
@@ -391,6 +404,7 @@ outer:
 		}
 	}
 
+	if !p.TagOverwrite {
 		// add metadata tags
 		for k, v := range p.metadataTags {
 			tags[k] = v
@@ -400,6 +414,7 @@ outer:
 		for k, v := range p.DefaultTags {
 			tags[k] = v
 		}
+	}
 
 	// will default to plugin name
 	measurementName := p.MetricName
@@ -471,6 +486,7 @@ func (p *Parser) InitFromConfig(config *parsers.Config) error {
 	p.ColumnNames = config.CSVColumnNames
 	p.ColumnTypes = config.CSVColumnTypes
 	p.TagColumns = config.CSVTagColumns
+	p.TagOverwrite = config.CSVTagOverwrite
 	p.MeasurementColumn = config.CSVMeasurementColumn
 	p.TimestampColumn = config.CSVTimestampColumn
 	p.TimestampFormat = config.CSVTimestampFormat

plugins/parsers/csv/parser_test.go

@@ -1015,32 +1015,47 @@ timestamp,type,name,status
 }
 
 func TestOverwriteDefaultTagsAndMetaDataTags(t *testing.T) {
-	// This tests makes sure that the default tags and metadata tags don't overwrite record data
+	csv := []byte(`second=orange
-	// This test also covers the scenario where the metadata overwrites the default tag
+fourth=plain
+1.4,apple,hi
+`)
+	defaultTags := map[string]string{"third": "bye", "fourth": "car"}
+
+	tests := []struct {
+		name         string
+		tagOverwrite bool
+		expectedTags map[string]string
+	}{
+		{
+			name:         "Don't overwrite tags",
+			tagOverwrite: false,
+			expectedTags: map[string]string{"second": "orange", "third": "bye", "fourth": "car"},
+		},
+		{
+			name:         "Overwrite tags",
+			tagOverwrite: true,
+			expectedTags: map[string]string{"second": "apple", "third": "hi", "fourth": "plain"},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
 			p := &Parser{
 				ColumnNames:        []string{"first", "second", "third"},
 				TagColumns:         []string{"second", "third"},
-		TimeFunc:           DefaultTime,
+				TagOverwrite:       tt.tagOverwrite,
 				MetadataRows:       2,
 				MetadataSeparators: []string{"="},
 			}
-	err := p.Init()
-	require.NoError(t, err)
-	p.SetDefaultTags(map[string]string{"third": "bye", "fourth": "car"})
-	m, err := p.ParseLine("second=orange")
-	require.ErrorIs(t, err, parsers.ErrEOF)
-	require.Nil(t, m)
-	m, err = p.ParseLine("fourth=plain")
-	require.NoError(t, err)
-	require.Nil(t, m)
-	expectedFields := []map[string]interface{}{{"first": 1.4}}
-	expectedTags := []map[string]string{{"second": "orange", "third": "bye", "fourth": "car"}}
 
-	m, err = p.ParseLine("1.4,apple,hi")
+			require.NoError(t, p.Init())
-	require.NoError(t, err)
+			p.SetDefaultTags(defaultTags)
 
-	require.Equal(t, expectedFields[0], m.Fields())
+			metrics, err := p.Parse(csv)
-	require.Equal(t, expectedTags[0], m.Tags())
+			require.NoError(t, err)
+			require.Len(t, metrics, 1)
+			require.EqualValues(t, tt.expectedTags, metrics[0].Tags())
+		})
+	}
 }
 
 func TestParseCSVResetModeInvalid(t *testing.T) {

plugins/parsers/registry.go

@@ -150,6 +150,7 @@ type Config struct {
 	CSVSkipColumns        int      `toml:"csv_skip_columns"`
 	CSVSkipRows           int      `toml:"csv_skip_rows"`
 	CSVTagColumns         []string `toml:"csv_tag_columns"`
+	CSVTagOverwrite       bool     `toml:"csv_tag_overwrite"`
 	CSVTimestampColumn    string   `toml:"csv_timestamp_column"`
 	CSVTimestampFormat    string   `toml:"csv_timestamp_format"`
 	CSVTimezone           string   `toml:"csv_timezone"`