0.3.0 Removing internal parallelism: httpjson and exec

plugins/exec/exec.go

@@ -3,13 +3,8 @@ package exec
 import (
 	"bytes"
 	"encoding/json"
-	"errors"
 	"fmt"
-	"math"
 	"os/exec"
-	"strings"
-	"sync"
-	"time"
 
 	"github.com/gonuts/go-shellquote"
 
@@ -18,47 +13,28 @@ import (
 )
 
 const sampleConfig = `
-  # specify commands via an array of tables
-  [[plugins.exec.commands]]
   # the command to run
   command = "/usr/bin/mycollector --foo=bar"
 
   # name of the command (used as a prefix for measurements)
   name = "mycollector"
-
-  # Only run this command if it has been at least this many
-  # seconds since it last ran
-  interval = 10
 `
 
 type Exec struct {
-	Commands []*Command
-	runner   Runner
-	clock    Clock
-}
+	Command string
+	Name    string
 
-type Command struct {
-	Command   string
-	Name      string
-	Interval  int
-	lastRunAt time.Time
+	runner Runner
 }
 
 type Runner interface {
-	Run(*Command) ([]byte, error)
-}
-
-type Clock interface {
-	Now() time.Time
+	Run(*Exec) ([]byte, error)
 }
 
 type CommandRunner struct{}
 
-type RealClock struct{}
-
-func (c CommandRunner) Run(command *Command) ([]byte, error) {
-	command.lastRunAt = time.Now()
-	split_cmd, err := shellquote.Split(command.Command)
+func (c CommandRunner) Run(e *Exec) ([]byte, error) {
+	split_cmd, err := shellquote.Split(e.Command)
 	if err != nil || len(split_cmd) == 0 {
 		return nil, fmt.Errorf("exec: unable to parse command, %s", err)
 	}
@@ -68,18 +44,14 @@ func (c CommandRunner) Run(command *Command) ([]byte, error) {
 	cmd.Stdout = &out
 
 	if err := cmd.Run(); err != nil {
-		return nil, fmt.Errorf("exec: %s for command '%s'", err, command.Command)
+		return nil, fmt.Errorf("exec: %s for command '%s'", err, e.Command)
 	}
 
 	return out.Bytes(), nil
 }
 
-func (c RealClock) Now() time.Time {
-	return time.Now()
-}
-
 func NewExec() *Exec {
-	return &Exec{runner: CommandRunner{}, clock: RealClock{}}
+	return &Exec{runner: CommandRunner{}}
 }
 
 func (e *Exec) SampleConfig() string {
@@ -91,72 +63,31 @@ func (e *Exec) Description() string {
 }
 
 func (e *Exec) Gather(acc plugins.Accumulator) error {
-	var wg sync.WaitGroup
-
-	errorChannel := make(chan error, len(e.Commands))
-
-	for _, c := range e.Commands {
-		wg.Add(1)
-		go func(c *Command, acc plugins.Accumulator) {
-			defer wg.Done()
-			err := e.gatherCommand(c, acc)
-			if err != nil {
-				errorChannel <- err
-			}
-		}(c, acc)
+	out, err := e.runner.Run(e)
+	if err != nil {
+		return err
 	}
 
-	wg.Wait()
-	close(errorChannel)
-
-	// Get all errors and return them as one giant error
-	errorStrings := []string{}
-	for err := range errorChannel {
-		errorStrings = append(errorStrings, err.Error())
+	var jsonOut interface{}
+	err = json.Unmarshal(out, &jsonOut)
+	if err != nil {
+		return fmt.Errorf("exec: unable to parse output of '%s' as JSON, %s",
+			e.Command, err)
 	}
 
-	if len(errorStrings) == 0 {
-		return nil
+	f := internal.JSONFlattener{}
+	err = f.FlattenJSON("", jsonOut)
+	if err != nil {
+		return err
 	}
-	return errors.New(strings.Join(errorStrings, "\n"))
-}
 
-func (e *Exec) gatherCommand(c *Command, acc plugins.Accumulator) error {
-	secondsSinceLastRun := 0.0
-
-	if c.lastRunAt.Unix() == 0 { // means time is uninitialized
-		secondsSinceLastRun = math.Inf(1)
+	var msrmnt_name string
+	if e.Name == "" {
+		msrmnt_name = "exec"
 	} else {
-		secondsSinceLastRun = (e.clock.Now().Sub(c.lastRunAt)).Seconds()
-	}
-
-	if secondsSinceLastRun >= float64(c.Interval) {
-		out, err := e.runner.Run(c)
-		if err != nil {
-			return err
-		}
-
-		var jsonOut interface{}
-		err = json.Unmarshal(out, &jsonOut)
-		if err != nil {
-			return fmt.Errorf("exec: unable to parse output of '%s' as JSON, %s",
-				c.Command, err)
-		}
-
-		f := internal.JSONFlattener{}
-		err = f.FlattenJSON("", jsonOut)
-		if err != nil {
-			return err
-		}
-
-		var msrmnt_name string
-		if c.Name == "" {
-			msrmnt_name = "exec"
-		} else {
-			msrmnt_name = "exec_" + c.Name
-		}
-		acc.AddFields(msrmnt_name, f.Fields, nil)
+		msrmnt_name = "exec_" + e.Name
 	}
+	acc.AddFields(msrmnt_name, f.Fields, nil)
 	return nil
 }