- Sign the CLA
- Make changes or write plugin (see below for details)
- Add your plugin to
plugins/inputs/all/all.go
orplugins/outputs/all/all.go
- If your plugin requires a new Go package, add it
- Write a README for your plugin, if it's an input plugin, it should be structured like the input example here. Output plugins READMEs are less structured, but any information you can provide on how the data will look is appreciated. See the OpenTSDB output for a good example.
Public interfaces for inputs, outputs, metrics, and the accumulator can be found on the GoDoc
Before we can merge a pull request, you will need to sign the CLA, which can be found on our website
Assuming you can already build the project, run these in the telegraf directory:
go get github.com/sparrc/gdm
gdm restore
gdm save
This section is for developers who want to create new collection inputs. Telegraf is entirely plugin driven. This interface allows for operators to pick and chose what is gathered and makes it easy for developers to create new ways of generating metrics.
Plugin authorship is kept as simple as possible to promote people to develop and submit new inputs.
- A plugin must conform to the
telegraf.Input
interface. - Input Plugins should call
inputs.Add
in theirinit
function to register themselves. See below for a quick example. - Input Plugins must be added to the
github.com/influxdata/telegraf/plugins/inputs/all/all.go
file. - The
SampleConfig
function should return valid toml that describes how the plugin can be configured. This is include intelegraf -sample-config
. - The
Description
function should say in one line what this plugin does.
Let's say you've written a plugin that emits metrics about processes on the current host.
package simple
// simple.go
import (
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/inputs"
)
type Simple struct {
Ok bool
}
func (s *Simple) Description() string {
return "a demo plugin"
}
func (s *Simple) SampleConfig() string {
return "ok = true # indicate if everything is fine"
}
func (s *Simple) Gather(acc telegraf.Accumulator) error {
if s.Ok {
acc.Add("state", "pretty good", nil)
} else {
acc.Add("state", "not great", nil)
}
return nil
}
func init() {
inputs.Add("simple", func() telegraf.Input { return &Simple{} })
}
Some input plugins (such as exec) accept arbitrary input data formats. An overview of these data formats can be found here.
In order to enable this, you must specify a SetParser(parser parsers.Parser)
function on the plugin object (see the exec plugin for an example), as well as
defining parser
as a field of the object.
You can then utilize the parser internally in your plugin, parsing data as you
see fit. Telegraf's configuration layer will take care of instantiating and
creating the Parser
object.
You should also add the following to your SampleConfig() return:
## Data format to consume.
## Each data format has it's own unique set of configuration options, read
## more about them here:
## https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
data_format = "influx"
Below is the Parser
interface.
// Parser is an interface defining functions that a parser plugin must satisfy.
type Parser interface {
// Parse takes a byte buffer separated by newlines
// ie, `cpu.usage.idle 90\ncpu.usage.busy 10`
// and parses it into telegraf metrics
Parse(buf []byte) ([]telegraf.Metric, error)
// ParseLine takes a single string metric
// ie, "cpu.usage.idle 90"
// and parses it into a telegraf metric.
ParseLine(line string) (telegraf.Metric, error)
}
And you can view the code here.
This section is for developers who want to create new "service" collection
inputs. A service plugin differs from a regular plugin in that it operates
a background service while Telegraf is running. One example would be the statsd
plugin, which operates a statsd server.
Service Input Plugins are substantially more complicated than a regular plugin, as they will require threads and locks to verify data integrity. Service Input Plugins should be avoided unless there is no way to create their behavior with a regular plugin.
Their interface is quite similar to a regular plugin, with the addition of Start()
and Stop()
methods.
- Same as the
Plugin
guidelines, except that they must conform to theinputs.ServiceInput
interface.
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
outputs.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. - The
SampleConfig
function should return valid toml that describes how the output can be configured. This is include intelegraf -sample-config
. - The
Description
function should say in one line what this output does.
package simpleoutput
// simpleoutput.go
import (
"github.com/influxdata/telegraf"
"github.com/influxdata/telegraf/plugins/outputs"
)
type Simple struct {
Ok bool
}
func (s *Simple) Description() string {
return "a demo output"
}
func (s *Simple) SampleConfig() string {
return "url = localhost"
}
func (s *Simple) Connect() error {
// Make a connection to the URL here
return nil
}
func (s *Simple) Close() error {
// Close connection to the URL here
return nil
}
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 file) can write arbitrary output data formats. An overview of these data formats can be found here.
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() return:
## Data format to output.
## Each data format has it's 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"
This section is for developers who want to create new "service" output. A
service output differs from a regular output in that it operates a background service
while Telegraf is running. One example would be the prometheus_client
output,
which operates an HTTP server.
Their interface is quite similar to a regular output, with the addition of Start()
and Stop()
methods.
- Same as the
Output
guidelines, except that they must conform to theoutput.ServiceOutput
interface.
execute make test-short
As Telegraf collects metrics from several third-party services it becomes a difficult task to mock each service as some of them have complicated protocols which would take some time to replicate.
To overcome this situation we've decided to use docker containers to provide a fast and reproducible environment to test those services which require it. For other situations (i.e: https://github.com/influxdata/telegraf/blob/master/plugins/inputs/redis/redis_test.go) a simple mock will suffice.
To execute Telegraf tests follow these simple steps:
- Install docker following these instructions
- execute
make test
Try cleaning up your test environment by executing make docker-kill
and
re-running