telegraf/agent.go

326 lines
5.6 KiB
Go

package telegraf
import (
"fmt"
"log"
"os"
"sort"
"sync"
"time"
"github.com/influxdb/telegraf/outputs"
"github.com/influxdb/telegraf/plugins"
)
type runningOutput struct {
name string
output outputs.Output
}
type runningPlugin struct {
name string
plugin plugins.Plugin
config *ConfiguredPlugin
}
// Agent runs telegraf and collects data based on the given config
type Agent struct {
// Interval at which to gather information
Interval Duration
// Run in debug mode?
Debug bool
Hostname string
Config *Config
outputs []*runningOutput
plugins []*runningPlugin
}
// NewAgent returns an Agent struct based off the given Config
func NewAgent(config *Config) (*Agent, error) {
agent := &Agent{Config: config, Interval: Duration{10 * time.Second}}
err := config.ApplyAgent(agent)
if err != nil {
return nil, err
}
if agent.Hostname == "" {
hostname, err := os.Hostname()
if err != nil {
return nil, err
}
agent.Hostname = hostname
}
if config.Tags == nil {
config.Tags = map[string]string{}
}
config.Tags["host"] = agent.Hostname
return agent, nil
}
func (a *Agent) Connect() error {
for _, o := range a.outputs {
err := o.output.Connect()
if err != nil {
return err
}
}
return nil
}
func (a *Agent) LoadOutputs() ([]string, error) {
var names []string
for _, name := range a.Config.OutputsDeclared() {
creator, ok := outputs.Outputs[name]
if !ok {
return nil, fmt.Errorf("Undefined but requested output: %s", name)
}
output := creator()
err := a.Config.ApplyOutput(name, output)
if err != nil {
return nil, err
}
a.outputs = append(a.outputs, &runningOutput{name, output})
names = append(names, name)
}
sort.Strings(names)
return names, nil
}
// LoadPlugins loads the agent's plugins
func (a *Agent) LoadPlugins() ([]string, error) {
var names []string
for _, name := range a.Config.PluginsDeclared() {
creator, ok := plugins.Plugins[name]
if !ok {
return nil, fmt.Errorf("Undefined but requested plugin: %s", name)
}
plugin := creator()
config, err := a.Config.ApplyPlugin(name, plugin)
if err != nil {
return nil, err
}
a.plugins = append(a.plugins, &runningPlugin{name, plugin, config})
names = append(names, name)
}
sort.Strings(names)
return names, nil
}
func (a *Agent) crankParallel() error {
points := make(chan *BatchPoints, len(a.plugins))
var wg sync.WaitGroup
for _, plugin := range a.plugins {
if plugin.config.Interval != 0 {
continue
}
wg.Add(1)
go func(plugin *runningPlugin) {
defer wg.Done()
var acc BatchPoints
acc.Debug = a.Debug
acc.Prefix = plugin.name + "_"
acc.Config = plugin.config
plugin.plugin.Gather(&acc)
points <- &acc
}(plugin)
}
wg.Wait()
close(points)
var bp BatchPoints
bp.Tags = a.Config.Tags
bp.Time = time.Now()
for sub := range points {
bp.Points = append(bp.Points, sub.Points...)
}
return a.flush(bp)
}
func (a *Agent) crank() error {
var acc BatchPoints
acc.Debug = a.Debug
for _, plugin := range a.plugins {
acc.Prefix = plugin.name + "_"
acc.Config = plugin.config
err := plugin.plugin.Gather(&acc)
if err != nil {
return err
}
}
acc.Tags = a.Config.Tags
acc.Time = time.Now()
return a.flush(acc)
}
func (a *Agent) crankSeparate(shutdown chan struct{}, plugin *runningPlugin) error {
ticker := time.NewTicker(plugin.config.Interval)
for {
var acc BatchPoints
acc.Debug = a.Debug
acc.Prefix = plugin.name + "_"
acc.Config = plugin.config
err := plugin.plugin.Gather(&acc)
if err != nil {
return err
}
acc.Tags = a.Config.Tags
acc.Time = time.Now()
err = a.flush(acc)
if err != nil {
return err
}
select {
case <-shutdown:
return nil
case <-ticker.C:
continue
}
}
}
func (a *Agent) flush(bp BatchPoints) error {
var wg sync.WaitGroup
var outerr error
for _, o := range a.outputs {
wg.Add(1)
go func(output *runningOutput) {
defer wg.Done()
outerr = o.output.Write(bp.BatchPoints)
}(o)
}
wg.Wait()
return outerr
}
// TestAllPlugins verifies that we can 'Gather' from all plugins with the
// default configuration
func (a *Agent) TestAllPlugins() error {
var names []string
for name := range plugins.Plugins {
names = append(names, name)
}
sort.Strings(names)
var acc BatchPoints
acc.Debug = true
fmt.Printf("* Testing all plugins with default configuration\n")
for _, name := range names {
plugin := plugins.Plugins[name]()
fmt.Printf("* Plugin: %s\n", name)
acc.Prefix = name + "_"
err := plugin.Gather(&acc)
if err != nil {
return err
}
}
return nil
}
// Test verifies that we can 'Gather' from all plugins with their configured
// Config struct
func (a *Agent) Test() error {
var acc BatchPoints
acc.Debug = true
for _, plugin := range a.plugins {
acc.Prefix = plugin.name + "_"
acc.Config = plugin.config
fmt.Printf("* Plugin: %s\n", plugin.name)
if plugin.config.Interval != 0 {
fmt.Printf("* Internal: %s\n", plugin.config.Interval)
}
err := plugin.plugin.Gather(&acc)
if err != nil {
return err
}
}
return nil
}
// Run runs the agent daemon, gathering every Interval
func (a *Agent) Run(shutdown chan struct{}) error {
var wg sync.WaitGroup
for _, plugin := range a.plugins {
if plugin.config.Interval != 0 {
wg.Add(1)
go func(plugin *runningPlugin) {
defer wg.Done()
a.crankSeparate(shutdown, plugin)
}(plugin)
}
}
defer wg.Wait()
ticker := time.NewTicker(a.Interval.Duration)
for {
err := a.crankParallel()
if err != nil {
log.Printf("Error in plugins: %s", err)
}
select {
case <-shutdown:
return nil
case <-ticker.C:
continue
}
}
}