Adding upstream version 1.34.4.

Signed-off-by: Daniel Baumann <daniel@debian.org>

plugins/processors/starlark/starlark.go

@@ -0,0 +1,142 @@
+//go:generate ../../../tools/readme_config_includer/generator
+package starlark
+
+import (
+	_ "embed"
+	"errors"
+	"fmt"
+
+	"go.starlark.net/starlark"
+
+	"github.com/influxdata/telegraf"
+	common "github.com/influxdata/telegraf/plugins/common/starlark"
+	"github.com/influxdata/telegraf/plugins/processors"
+)
+
+//go:embed sample.conf
+var sampleConfig string
+
+type Starlark struct {
+	common.Common
+
+	results []telegraf.Metric
+}
+
+func (*Starlark) SampleConfig() string {
+	return sampleConfig
+}
+
+func (s *Starlark) Init() error {
+	if err := s.Common.Init(); err != nil {
+		return err
+	}
+
+	// The source should define an apply function.
+	if err := s.AddFunction("apply", &common.Metric{}); err != nil {
+		return err
+	}
+
+	// Preallocate a slice for return values.
+	s.results = make([]telegraf.Metric, 0, 10)
+
+	return nil
+}
+
+func (*Starlark) Start(telegraf.Accumulator) error {
+	return nil
+}
+
+func (s *Starlark) Add(origMetric telegraf.Metric, acc telegraf.Accumulator) error {
+	parameters, found := s.GetParameters("apply")
+	if !found {
+		return errors.New("the parameters of the apply function could not be found")
+	}
+	parameters[0].(*common.Metric).Wrap(origMetric)
+
+	returnValue, err := s.Call("apply")
+	if err != nil {
+		s.LogError(err)
+		return err
+	}
+
+	switch rv := returnValue.(type) {
+	case *starlark.List:
+		iter := rv.Iterate()
+		defer iter.Done()
+		var v starlark.Value
+		var origFound bool
+		for iter.Next(&v) {
+			switch v := v.(type) {
+			case *common.Metric:
+				m := v.Unwrap()
+				if containsMetric(s.results, m) {
+					s.Log.Errorf("Duplicate metric reference detected")
+					continue
+				}
+
+				// Previous metric was found, accept the starlark metric, add
+				// the original metric to the accumulator
+				if v.ID != 0 {
+					origFound = true
+					s.results = append(s.results, origMetric)
+					acc.AddMetric(origMetric)
+					continue
+				}
+
+				s.results = append(s.results, m)
+				acc.AddMetric(m)
+			default:
+				s.Log.Errorf("Invalid type returned in list: %s", v.Type())
+			}
+		}
+
+		// If the script didn't return the original metrics, mark it as
+		// successfully handled.
+		if !origFound {
+			origMetric.Drop()
+		}
+
+		// clear results
+		for i := range s.results {
+			s.results[i] = nil
+		}
+		s.results = s.results[:0]
+	case *common.Metric:
+		m := rv.Unwrap()
+		// If we got the original metric back, use that and drop the new one.
+		// Otherwise mark the original as accepted and use the new metric.
+		if rv.ID != 0 {
+			acc.AddMetric(origMetric)
+		} else {
+			origMetric.Accept()
+			acc.AddMetric(m)
+		}
+	case starlark.NoneType:
+		origMetric.Drop()
+	default:
+		return fmt.Errorf("invalid type returned: %T", rv)
+	}
+
+	return nil
+}
+
+func (*Starlark) Stop() {}
+
+func containsMetric(metrics []telegraf.Metric, target telegraf.Metric) bool {
+	for _, m := range metrics {
+		if m == target {
+			return true
+		}
+	}
+	return false
+}
+
+func init() {
+	processors.AddStreaming("starlark", func() telegraf.StreamingProcessor {
+		return &Starlark{
+			Common: common.Common{
+				StarlarkLoadFunc: common.LoadFunc,
+			},
+		}
+	})
+}