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telegraf/plugins/outputs/mqtt/topic_name_generator.go
Daniel Baumann 4978089aab
Adding upstream version 1.34.4.
Signed-off-by: Daniel Baumann <daniel@debian.org>
2025-05-24 07:26:29 +02:00

88 lines
2.1 KiB
Go

package mqtt
import (
"fmt"
"strings"
"text/template"
"time"
"github.com/Masterminds/sprig/v3"
"github.com/influxdata/telegraf"
)
type TopicNameGenerator struct {
TopicPrefix string
metric telegraf.TemplateMetric
template *template.Template
}
func NewTopicNameGenerator(topicPrefix, topic string) (*TopicNameGenerator, error) {
topic = hostnameRe.ReplaceAllString(topic, `$1.Tag "host"$2`)
topic = pluginNameRe.ReplaceAllString(topic, `$1.Name$2`)
tt, err := template.New("topic_name").Funcs(sprig.TxtFuncMap()).Parse(topic)
if err != nil {
return nil, err
}
for _, p := range strings.Split(topic, "/") {
if strings.ContainsAny(p, "#+") {
return nil, fmt.Errorf("found forbidden character %s in the topic name %s", p, topic)
}
}
return &TopicNameGenerator{TopicPrefix: topicPrefix, template: tt}, nil
}
func (t *TopicNameGenerator) Name() string {
return t.metric.Name()
}
func (t *TopicNameGenerator) Tag(key string) string {
return t.metric.Tag(key)
}
func (t *TopicNameGenerator) Field(key string) interface{} {
return t.metric.Field(key)
}
func (t *TopicNameGenerator) Time() time.Time {
return t.metric.Time()
}
func (t *TopicNameGenerator) Tags() map[string]string {
return t.metric.Tags()
}
func (t *TopicNameGenerator) Fields() map[string]interface{} {
return t.metric.Fields()
}
func (t *TopicNameGenerator) String() string {
return t.metric.String()
}
func (m *MQTT) generateTopic(metric telegraf.Metric) (string, error) {
m.generator.metric = metric.(telegraf.TemplateMetric)
// Cannot directly pass TemplateMetric since TopicNameGenerator still contains TopicPrefix (until v1.35.0)
var b strings.Builder
err := m.generator.template.Execute(&b, m.generator)
if err != nil {
return "", err
}
var ts []string
for _, p := range strings.Split(b.String(), "/") {
if p != "" {
ts = append(ts, p)
}
}
topic := strings.Join(ts, "/")
// This is to keep backward compatibility with previous behaviour where the plugin name was always present
if topic == "" {
return metric.Name(), nil
}
if strings.HasPrefix(b.String(), "/") {
topic = "/" + topic
}
return topic, nil
}