This section is for developers who want to create a new output sink. Outputs are created in a similar manner as collection plugins, and their interface has similar constructs.
- An output must conform to the telegraf.Output interface.
- Outputs should call
outputs.Add
in theirinit
function to register themselves. See below for a quick example. - To be available within Telegraf itself, plugins must add themselves to the
github.com/influxdata/telegraf/plugins/outputs/all/all.go
file. - Each plugin requires a file called
sample.conf
containing the sample configuration for the plugin in TOML format. Please consult the Sample Config page for the latest style guidelines. - Each plugin
README.md
file should include thesample.conf
file in a section describing the configuration by specifying atoml
section in the formtoml @sample.conf
. The specified file(s) are then injected automatically into the Readme. - Follow the recommended Code Style.
//go:generate ../../../tools/readme_config_includer/generator
package simpleoutput
// simpleoutput.go
import (
_ "embed"
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/outputs"
)
// DO NOT REMOVE THE NEXT TWO LINES! This is required to embed the sampleConfig data.
//go:embed sample.conf
var sampleConfig string
type Simple struct {
Ok bool `toml:"ok"`
Log telegraf.Logger `toml:"-"`
}
func (*Simple) SampleConfig() string {
return sampleConfig
}
// Init is for setup, and validating config.
func (s *Simple) Init() error {
return nil
}
func (s *Simple) Connect() error {
// Make any connection required here
return nil
}
func (s *Simple) Close() error {
// Close any connections here.
// Write will not be called once Close is called, so there is no need to synchronize.
return nil
}
// Write should write immediately to the output, and not buffer writes
// (Telegraf manages the buffer for you). Returning an error will fail this
// batch of writes and the entire batch will be retried automatically.
func (s *Simple) Write(metrics []telegraf.Metric) error {
for _, metric := range metrics {
// write `metric` to the output sink here
}
return nil
}
func init() {
outputs.Add("simpleoutput", func() telegraf.Output { return &Simple{} })
}
Some output plugins, such as the file plugin, can write in any supported output data formats.
In order to enable this, you must specify a
SetSerializer(serializer serializers.Serializer)
function on the plugin object (see the file plugin for an example), as well as
defining serializer
as a field of the object.
You can then utilize the serializer internally in your plugin, serializing data
before it's written. Telegraf's configuration layer will take care of
instantiating and creating the Serializer
object.
You should also add the following to your SampleConfig()
:
## Data format to output.
## Each data format has its own unique set of configuration options, read
## more about them here:
## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_OUTPUT.md
data_format = "influx"
Metrics are flushed to outputs when any of the following events happen:
flush_interval + rand(flush_jitter)
has elapsed since start or the last flush interval- At least
metric_batch_size
count of metrics are waiting in the buffer - The telegraf process has received a SIGUSR1 signal
Note that if the flush takes longer than the agent.interval
to write the metrics
to the output, you'll see a message saying the output did not complete within its flush interval
. This may mean your output is not keeping up with the flow of metrics,
and you may want to look into enabling compression, reducing the size of your metrics,
or investigate other reasons why the writes might be taking longer than expected.