Add Drop Strings Processor

plugins/processors/all/all.go

@@ -1,5 +1,6 @@
 package all
 
 import (
+ _ "github.com/influxdata/telegraf/plugins/processors/drop_strings"
  _ "github.com/influxdata/telegraf/plugins/processors/printer"
 )

plugins/processors/drop_strings/README.md

@@ -0,0 +1,14 @@
+# Drop Strings Processor Plugin
+
+The drop strings processor plugin drops all fields of type string.
+
+### Configuration:
+
+```toml
+# Drop all fields of type string, that pass through this processor.
+[[processors.drop_strings]]
+```
+
+### Tags:
+
+No tags are applied by this processor.

plugins/processors/drop_strings/drop_strings.go

@@ -0,0 +1,60 @@
+package drop_strings
+
+import (
+ "fmt"
+
+ "github.com/influxdata/telegraf"
+ "github.com/influxdata/telegraf/metric"
+ "github.com/influxdata/telegraf/plugins/processors"
+)
+
+type DropStrings struct {
+}
+
+var sampleConfig = `
+`
+
+func (d *DropStrings) SampleConfig() string {
+ return sampleConfig
+}
+
+func (d *DropStrings) Description() string {
+ return "Drops all metrics of type string that pass through this filter."
+}
+
+func (d *DropStrings) Apply(in ...telegraf.Metric) []telegraf.Metric {
+ out := make([]telegraf.Metric, 0, len(in))
+ for _, source := range in {
+ target, error := dropStrings(source)
+ if error == nil {
+ out = append(out, target)
+ }
+ }
+ return out
+}
+
+func dropStrings(source telegraf.Metric) (telegraf.Metric, error) {
+ inFields := source.Fields()
+ outFields := make(map[string]interface{}, len(inFields))
+ changed := false
+ for key, value := range inFields {
+ if _, drop := value.(string); !drop {
+ outFields[key] = value
+ } else {
+ changed = true
+ }
+ }
+ if !changed {
+ return source, nil
+ }
+ if changed && len(outFields) > 0 {
+ return metric.New(source.Name(), source.Tags(), outFields, source.Time(), source.Type())
+ }
+ return nil, fmt.Errorf("No more fields in metric '%s'", source.Name())
+}
+
+func init() {
+ processors.Add("drop_strings", func() telegraf.Processor {
+ return &DropStrings{}
+ })
+}

plugins/processors/drop_strings/drop_strings_test.go

@@ -0,0 +1,60 @@
+package drop_strings
+
+import (
+ "testing"
+ "time"
+
+ "github.com/influxdata/telegraf/metric"
+ "github.com/stretchr/testify/assert"
+)
+
+func TestDropStrings(t *testing.T) {
+ var metric, _ = metric.New("Test Metric",
+ map[string]string{"state": "full"},
+ map[string]interface{}{
+ "integer": int64(23),
+ "float": float64(3.1415),
+ "bool": true,
+ "string": "should be dropped",
+ },
+ time.Now(),
+ )
+
+ dropStrings := DropStrings{}
+
+ result := dropStrings.Apply(metric)[0]
+ fields := result.Fields()
+
+ assert.NotContains(t, fields, "string")
+
+ assertFieldValue(t, int64(23), "integer", fields)
+ assertFieldValue(t, float64(3.1415), "float", fields)
+ assertFieldValue(t, true, "bool", fields)
+
+ assert.Equal(t, "Test Metric", result.Name())
+ assert.Equal(t, metric.Tags(), result.Tags())
+ assert.Equal(t, metric.Time(), result.Time())
+}
+
+func assertFieldValue(t *testing.T, expected interface{}, field string, fields map[string]interface{}) {
+ value, present := fields[field]
+ assert.True(t, present, "value of field '"+field+"' was not present")
+ assert.EqualValues(t, expected, value)
+}
+
+func TestDropEntireMetricIfOnlyStrings(t *testing.T) {
+ var metric, _ = metric.New("Test Metric",
+ map[string]string{"state": "full"},
+ map[string]interface{}{
+ "string1": "should be dropped",
+ "string2": "should be dropped, also",
+ },
+ time.Now(),
+ )
+
+ dropStrings := DropStrings{}
+
+ result := dropStrings.Apply(metric)
+
+ assert.Len(t, result, 0, "No metric should be emitted.")
+}