Adding upstream version 1.34.4.

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

plugins/processors/lookup/lookup.go

@@ -0,0 +1,215 @@
+//go:generate ../../../tools/readme_config_includer/generator
+package lookup
+
+import (
+	"bytes"
+	_ "embed"
+	"encoding/csv"
+	"encoding/json"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strings"
+	"text/template"
+
+	"github.com/influxdata/telegraf"
+	"github.com/influxdata/telegraf/plugins/processors"
+)
+
+//go:embed sample.conf
+var sampleConfig string
+
+type Processor struct {
+	Filenames   []string        `toml:"files"`
+	Fileformat  string          `toml:"format"`
+	KeyTemplate string          `toml:"key"`
+	Log         telegraf.Logger `toml:"-"`
+
+	tmpl     *template.Template
+	mappings map[string][]telegraf.Tag
+}
+
+func (*Processor) SampleConfig() string {
+	return sampleConfig
+}
+
+func (p *Processor) Init() error {
+	if len(p.Filenames) < 1 {
+		return errors.New("missing 'files'")
+	}
+
+	if p.KeyTemplate == "" {
+		return errors.New("missing 'key_template'")
+	}
+
+	tmpl, err := template.New("key").Parse(p.KeyTemplate)
+	if err != nil {
+		return fmt.Errorf("creating template failed: %w", err)
+	}
+	p.tmpl = tmpl
+
+	p.mappings = make(map[string][]telegraf.Tag)
+	switch strings.ToLower(p.Fileformat) {
+	case "", "json":
+		return p.loadJSONFiles()
+	case "csv_key_name_value":
+		return p.loadCSVKeyNameValueFiles()
+	case "csv_key_values":
+		return p.loadCSVKeyValuesFiles()
+	}
+
+	return fmt.Errorf("invalid format %q", p.Fileformat)
+}
+
+func (p *Processor) Apply(in ...telegraf.Metric) []telegraf.Metric {
+	out := make([]telegraf.Metric, 0, len(in))
+	for _, raw := range in {
+		m := raw
+		if wm, ok := raw.(telegraf.UnwrappableMetric); ok {
+			m = wm.Unwrap()
+		}
+
+		var buf bytes.Buffer
+		if err := p.tmpl.Execute(&buf, m); err != nil {
+			p.Log.Errorf("generating key failed: %v", err)
+			p.Log.Debugf("metric was %v", m)
+		} else if tags, found := p.mappings[buf.String()]; found {
+			for _, tag := range tags {
+				m.AddTag(tag.Key, tag.Value)
+			}
+		}
+		out = append(out, raw)
+	}
+	return out
+}
+
+func (p *Processor) loadJSONFiles() error {
+	for _, fn := range p.Filenames {
+		buf, err := os.ReadFile(fn)
+		if err != nil {
+			return fmt.Errorf("loading %q failed: %w", fn, err)
+		}
+
+		var data map[string]map[string]string
+		if err := json.Unmarshal(buf, &data); err != nil {
+			return fmt.Errorf("parsing %q failed: %w", fn, err)
+		}
+
+		for key, tags := range data {
+			for k, v := range tags {
+				p.mappings[key] = append(p.mappings[key], telegraf.Tag{Key: k, Value: v})
+			}
+		}
+	}
+	return nil
+}
+
+func (p *Processor) loadCSVKeyNameValueFiles() error {
+	for _, fn := range p.Filenames {
+		if err := p.loadCSVKeyNameValueFile(fn); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (p *Processor) loadCSVKeyNameValueFile(fn string) error {
+	f, err := os.Open(fn)
+	if err != nil {
+		return fmt.Errorf("loading %q failed: %w", fn, err)
+	}
+	defer f.Close()
+
+	reader := csv.NewReader(f)
+	reader.Comment = '#'
+	reader.FieldsPerRecord = -1
+	reader.TrimLeadingSpace = true
+
+	line := 0
+	for {
+		line++
+		data, err := reader.Read()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return fmt.Errorf("reading line %d in %q failed: %w", line, fn, err)
+		}
+		if len(data) < 3 {
+			return fmt.Errorf("line %d in %q has not enough columns, requiring at least `key,name,value`", line, fn)
+		}
+		if len(data)%2 != 1 {
+			return fmt.Errorf("line %d in %q has a tag-name without value", line, fn)
+		}
+
+		key := data[0]
+		for i := 1; i < len(data)-1; i += 2 {
+			k, v := data[i], data[i+1]
+			p.mappings[key] = append(p.mappings[key], telegraf.Tag{Key: k, Value: v})
+		}
+	}
+
+	return nil
+}
+
+func (p *Processor) loadCSVKeyValuesFiles() error {
+	for _, fn := range p.Filenames {
+		if err := p.loadCSVKeyValuesFile(fn); err != nil {
+			return err
+		}
+	}
+	return nil
+}
+
+func (p *Processor) loadCSVKeyValuesFile(fn string) error {
+	f, err := os.Open(fn)
+	if err != nil {
+		return fmt.Errorf("loading %q failed: %w", fn, err)
+	}
+	defer f.Close()
+
+	reader := csv.NewReader(f)
+	reader.Comment = '#'
+	reader.TrimLeadingSpace = true
+
+	// Read the first line which should be the header
+	header, err := reader.Read()
+	if err != nil {
+		if errors.Is(err, io.EOF) {
+			return fmt.Errorf("missing header in %q", fn)
+		}
+		return fmt.Errorf("reading header in %q failed: %w", fn, err)
+	}
+	if len(header) < 2 {
+		return fmt.Errorf("header in %q has not enough columns, requiring at least `key,value`", fn)
+	}
+	header = header[1:]
+
+	line := 1
+	for {
+		line++
+		data, err := reader.Read()
+		if err != nil {
+			if errors.Is(err, io.EOF) {
+				break
+			}
+			return fmt.Errorf("reading line %d in %q failed: %w", line, fn, err)
+		}
+
+		key := data[0]
+		for i, v := range data[1:] {
+			v = strings.TrimSpace(v)
+			if v != "" {
+				p.mappings[key] = append(p.mappings[key], telegraf.Tag{Key: header[i], Value: v})
+			}
+		}
+	}
+
+	return nil
+}
+func init() {
+	processors.Add("lookup", func() telegraf.Processor {
+		return &Processor{}
+	})
+}