150 lines
5.3 KiB
Markdown
150 lines
5.3 KiB
Markdown
### Input Plugins
|
|
|
|
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.
|
|
|
|
### Input Plugin Guidelines
|
|
|
|
- A plugin must conform to the [telegraf.Input][] interface.
|
|
- Input Plugins should call `inputs.Add` in their `init` 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 included in `telegraf config`. Please
|
|
consult the [SampleConfig][] page for the latest style
|
|
guidelines.
|
|
- The `Description` function should say in one line what this plugin does.
|
|
- Follow the recommended [CodeStyle][].
|
|
|
|
Let's say you've written a plugin that emits metrics about processes on the
|
|
current host.
|
|
|
|
### Input Plugin Example
|
|
|
|
```go
|
|
package simple
|
|
|
|
// simple.go
|
|
|
|
import (
|
|
"github.com/influxdata/telegraf"
|
|
"github.com/influxdata/telegraf/plugins/inputs"
|
|
)
|
|
|
|
type Simple struct {
|
|
Ok bool `toml:"ok"`
|
|
}
|
|
|
|
func (s *Simple) Description() string {
|
|
return "a demo plugin"
|
|
}
|
|
|
|
func (s *Simple) SampleConfig() string {
|
|
return `
|
|
## Indicate if everything is fine
|
|
ok = true
|
|
`
|
|
}
|
|
|
|
func (s *Simple) Init() error {
|
|
return nil
|
|
}
|
|
|
|
func (s *Simple) Gather(acc telegraf.Accumulator) error {
|
|
if s.Ok {
|
|
acc.AddFields("state", map[string]interface{}{"value": "pretty good"}, nil)
|
|
} else {
|
|
acc.AddFields("state", map[string]interface{}{"value": "not great"}, nil)
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
func init() {
|
|
inputs.Add("simple", func() telegraf.Input { return &Simple{} })
|
|
}
|
|
```
|
|
|
|
### Development
|
|
|
|
* Run `make static` followed by `make plugin-[pluginName]` to spin up a docker
|
|
dev environment using docker-compose.
|
|
* ***[Optional]*** When developing a plugin, add a `dev` directory with a
|
|
`docker-compose.yml` and `telegraf.conf` as well as any other supporting
|
|
files, where sensible.
|
|
|
|
### Typed Metrics
|
|
|
|
In addition the the `AddFields` function, the accumulator also supports
|
|
functions to add typed metrics: `AddGauge`, `AddCounter`, etc. Metric types
|
|
are ignored by the InfluxDB output, but can be used for other outputs, such as
|
|
[prometheus][prom metric types].
|
|
|
|
### Data Formats
|
|
|
|
Some input plugins, such as the [exec][] plugin, can accept any supported
|
|
[input data formats][].
|
|
|
|
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.
|
|
|
|
Add the following to the `SampleConfig()`:
|
|
|
|
```toml
|
|
## Data format to consume.
|
|
## 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_INPUT.md
|
|
data_format = "influx"
|
|
```
|
|
|
|
### Service Input Plugins
|
|
|
|
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.
|
|
|
|
To create a Service Input implement the [telegraf.ServiceInput][] interface.
|
|
|
|
### Metric Tracking
|
|
|
|
Metric Tracking provides a system to be notified when metrics have been
|
|
successfully written to their outputs or otherwise discarded. This allows
|
|
inputs to be created that function as reliable queue consumers.
|
|
|
|
To get started with metric tracking begin by calling `WithTracking` on the
|
|
[telegraf.Accumulator][]. Add metrics using the `AddTrackingMetricGroup`
|
|
function on the returned [telegraf.TrackingAccumulator][] and store the
|
|
`TrackingID`. The `Delivered()` channel will return a type with information
|
|
about the final delivery status of the metric group.
|
|
|
|
Check the [amqp_consumer][] for an example implementation.
|
|
|
|
[exec]: https://github.com/influxdata/telegraf/tree/master/plugins/inputs/exec
|
|
[amqp_consumer]: https://github.com/influxdata/telegraf/tree/master/plugins/inputs/amqp_consumer
|
|
[prom metric types]: https://prometheus.io/docs/concepts/metric_types/
|
|
[input data formats]: https://github.com/influxdata/telegraf/blob/master/docs/DATA_FORMATS_INPUT.md
|
|
[SampleConfig]: https://github.com/influxdata/telegraf/wiki/SampleConfig
|
|
[CodeStyle]: https://github.com/influxdata/telegraf/wiki/CodeStyle
|
|
[telegraf.Input]: https://godoc.org/github.com/influxdata/telegraf#Input
|
|
[telegraf.ServiceInput]: https://godoc.org/github.com/influxdata/telegraf#ServiceInput
|
|
[telegraf.Accumulator]: https://godoc.org/github.com/influxdata/telegraf#Accumulator
|
|
[telegraf.TrackingAccumulator]: https://godoc.org/github.com/influxdata/telegraf#Accumulator
|