diff --git a/README.md b/README.md index b7e1e9fdb..a13530fca 100644 --- a/README.md +++ b/README.md @@ -1,10 +1,16 @@ # Telegraf - A native agent for InfluxDB [![Circle CI](https://circleci.com/gh/influxdb/telegraf.svg?style=svg)](https://circleci.com/gh/influxdb/telegraf) -Telegraf is an agent written in Go for collecting metrics from the system it's running on or from other services and writing them into InfluxDB. +Telegraf is an agent written in Go for collecting metrics from the system it's +running on or from other services and writing them into InfluxDB. -Design goals are to have a minimal memory footprint with a plugin system so that developers in the community can easily add support for collecting metrics from well known services (like Hadoop, or Postgres, or Redis) and third party APIs (like Mailchimp, AWS CloudWatch, or Google Analytics). +Design goals are to have a minimal memory footprint with a plugin system so +that developers in the community can easily add support for collecting metrics +from well known services (like Hadoop, or Postgres, or Redis) and third party +APIs (like Mailchimp, AWS CloudWatch, or Google Analytics). -We'll eagerly accept pull requests for new plugins and will manage the set of plugins that Telegraf supports. See the bottom of this doc for instructions on writing new plugins. +We'll eagerly accept pull requests for new plugins and will manage the set of +plugins that Telegraf supports. See the bottom of this doc for instructions on +writing new plugins. ## Quickstart @@ -34,11 +40,18 @@ brew install telegraf ## Telegraf Options -Telegraf has a few options you can configure under the `agent` section of the config. If you don't see an `agent` section run `telegraf -sample-config > telegraf.toml` to create a valid initial configuration: +Telegraf has a few options you can configure under the `agent` section of the +config. If you don't see an `agent` section run +`telegraf -sample-config > telegraf.toml` to create a valid initial +configuration: -* **hostname**: The hostname is passed as a tag. By default this will be the value retured by `hostname` on the machine running Telegraf. You can override that value here. -* **interval**: How ofter to gather metrics. Uses a simple number + unit parser, ie "10s" for 10 seconds or "5m" for 5 minutes. -* **debug**: Set to true to gather and send metrics to STDOUT as well as InfluxDB. +* **hostname**: The hostname is passed as a tag. By default this will be +the value retured by `hostname` on the machine running Telegraf. +You can override that value here. +* **interval**: How ofter to gather metrics. Uses a simple number + +unit parser, ie "10s" for 10 seconds or "5m" for 5 minutes. +* **debug**: Set to true to gather and send metrics to STDOUT as well as +InfluxDB. ## Supported Plugins @@ -58,19 +71,25 @@ Telegraf currently has support for collecting metrics from: * Lustre2 * Memcached -We'll be adding support for many more over the coming months. Read on if you want to add support for another service or third-party API. +We'll be adding support for many more over the coming months. Read on if you +want to add support for another service or third-party API. ## Plugin Options There are 3 configuration options that are configurable per plugin: -* **pass**: An array of strings that is used to filter metrics generated by the current plugin. Each string in the array is tested as a prefix against metrics and if it matches, the metric is emitted. +* **pass**: An array of strings that is used to filter metrics generated by the +current plugin. Each string in the array is tested as a prefix against metrics +and if it matches, the metric is emitted. * **drop**: The inverse of pass, if a metric matches, it is not emitted. -* **interval**: How often to gather this metric. Normal plugins use a single global interval, but if one particular plugin should be run less or more often, you can configure that here. +* **interval**: How often to gather this metric. Normal plugins use a single +global interval, but if one particular plugin should be run less or more often, +you can configure that here. ## Plugins -This section is for developers that want to create new collection plugins. Telegraf is entirely plugin driven. This interface allows for operators to +This section is for developers that want to create new collection plugins. +Telegraf is entirely plugin driven. This interface allows for operators to pick and chose what is gathered as well as makes it easy for developers to create new ways of generating metrics. @@ -86,22 +105,27 @@ developers don't have to worry about thread safety within these functions. it prepended. This is to keep plugins honest. * Plugins should call `plugins.Add` in their `init` function to register themselves. See below for a quick example. -* To be available within Telegraf itself, plugins must add themselves to the `github.com/influxdb/telegraf/plugins/all/all.go` file. -* The `SampleConfig` function should return valid toml that describes how the plugin can be configured. This is include in `telegraf -sample-config`. +* To be available within Telegraf itself, plugins must add themselves to the +`github.com/influxdb/telegraf/plugins/all/all.go` file. +* The `SampleConfig` function should return valid toml that describes how the +plugin can be configured. This is include in `telegraf -sample-config`. * The `Description` function should say in one line what this plugin does. ### Plugin interface ```go type Plugin interface { - SampleConfig() string - Description() string - Gather(Accumulator) error + SampleConfig() string + Description() string + Gather(Accumulator) error } type Accumulator interface { - Add(measurement string, value interface{}, tags map[string]string) - AddValuesWithTime(measurement string, values map[string]interface{}, tags map[string]string, timestamp time.Time) + Add(measurement string, value interface{}, tags map[string]string) + AddValuesWithTime(measurement string, + values map[string]interface{}, + tags map[string]string, + timestamp time.Time) } ``` @@ -118,7 +142,9 @@ The `Add` function takes 3 arguments: * **bool**: `true` or `false`, useful to indicate the presence of a state. `light_on`, etc. * **string**: Typically used to indicate a message, or some kind of freeform information. * **time.Time**: Useful for indicating when a state last occurred, for instance `light_on_since`. -* **tags**: This is a map of strings to strings to describe the where or who about the metric. For instance, the `net` plugin adds a tag named `"interface"` set to the name of the network interface, like `"eth0"`. +* **tags**: This is a map of strings to strings to describe the where or who +about the metric. For instance, the `net` plugin adds a tag named `"interface"` +set to the name of the network interface, like `"eth0"`. The `AddValuesWithTime` allows multiple values for a point to be passed. The values used are the same type profile as **value** above. The **timestamp** argument @@ -129,20 +155,20 @@ Let's say you've written a plugin that emits metrics about processes on the curr ```go type Process struct { - CPUTime float64 - MemoryBytes int64 - PID int + CPUTime float64 + MemoryBytes int64 + PID int } func Gather(acc plugins.Accumulator) error { - for _, process := range system.Processes() { - tags := map[string]string { - "pid": fmt.Sprintf("%d", process.Pid), - } + for _, process := range system.Processes() { + tags := map[string]string { + "pid": fmt.Sprintf("%d", process.Pid), + } - acc.Add("cpu", process.CPUTime, tags) - acc.Add("memory", process.MemoryBytes, tags) - } + acc.Add("cpu", process.CPUTime, tags) + acc.Add("memory", process.MemoryBytes, tags) + } } ``` @@ -156,29 +182,29 @@ package simple import "github.com/influxdb/telegraf/plugins" type Simple struct { - Ok bool + Ok bool } func (s *Simple) Description() string { - return "a demo plugin" + return "a demo plugin" } func (s *Simple) SampleConfig() string { - return "ok = true # indicate if everything is fine" + return "ok = true # indicate if everything is fine" } func (s *Simple) Gather(acc plugins.Accumulator) error { - if s.Ok { - acc.Add("state", "pretty good", nil) - } else { - acc.Add("state", "not great", nil) - } + if s.Ok { + acc.Add("state", "pretty good", nil) + } else { + acc.Add("state", "not great", nil) + } - return nil + return nil } func init() { - plugins.Add("simple", func() plugins.Plugin { return &Simple{} }) + plugins.Add("simple", func() plugins.Plugin { return &Simple{} }) } ``` @@ -186,7 +212,7 @@ func init() { ### Execute short tests: -execute `make short-test` +execute `make test-short` ### Execute long tests: @@ -202,8 +228,9 @@ a simple mock will suffice. To execute Telegraf tests follow these simple steps: -- Install docker compose following [these](https://docs.docker.com/compose/install/) instructions - - NOTE: mac users should be able to simply do `brew install boot2docker` +- Install docker compose following [these](https://docs.docker.com/compose/install/) +instructions + - mac users should be able to simply do `brew install boot2docker` and `brew install docker-compose` - execute `make test`