152 lines
3.4 KiB
Go
152 lines
3.4 KiB
Go
package exec
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
"log"
|
|
"os/exec"
|
|
"time"
|
|
|
|
"github.com/influxdata/telegraf"
|
|
"github.com/influxdata/telegraf/internal"
|
|
"github.com/influxdata/telegraf/plugins/outputs"
|
|
"github.com/influxdata/telegraf/plugins/serializers"
|
|
)
|
|
|
|
const maxStderrBytes = 512
|
|
|
|
// Exec defines the exec output plugin.
|
|
type Exec struct {
|
|
Command []string `toml:"command"`
|
|
Timeout internal.Duration `toml:"timeout"`
|
|
|
|
runner Runner
|
|
serializer serializers.Serializer
|
|
}
|
|
|
|
var sampleConfig = `
|
|
## Command to injest metrics via stdin.
|
|
command = ["tee", "-a", "/dev/null"]
|
|
|
|
## Timeout for command to complete.
|
|
# timeout = "5s"
|
|
|
|
## Data format to output.
|
|
## 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_OUTPUT.md
|
|
# data_format = "influx"
|
|
`
|
|
|
|
// SetSerializer sets the serializer for the output.
|
|
func (e *Exec) SetSerializer(serializer serializers.Serializer) {
|
|
e.serializer = serializer
|
|
}
|
|
|
|
// Connect satisfies the Ouput interface.
|
|
func (e *Exec) Connect() error {
|
|
return nil
|
|
}
|
|
|
|
// Close satisfies the Ouput interface.
|
|
func (e *Exec) Close() error {
|
|
return nil
|
|
}
|
|
|
|
// Description describes the plugin.
|
|
func (e *Exec) Description() string {
|
|
return "Send metrics to command as input over stdin"
|
|
}
|
|
|
|
// SampleConfig returns a sample configuration.
|
|
func (e *Exec) SampleConfig() string {
|
|
return sampleConfig
|
|
}
|
|
|
|
// Write writes the metrics to the configured command.
|
|
func (e *Exec) Write(metrics []telegraf.Metric) error {
|
|
var buffer bytes.Buffer
|
|
serializedMetrics, err := e.serializer.SerializeBatch(metrics)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
buffer.Write(serializedMetrics)
|
|
|
|
if buffer.Len() <= 0 {
|
|
return nil
|
|
}
|
|
|
|
return e.runner.Run(e.Timeout.Duration, e.Command, &buffer)
|
|
}
|
|
|
|
// Runner provides an interface for running exec.Cmd.
|
|
type Runner interface {
|
|
Run(time.Duration, []string, io.Reader) error
|
|
}
|
|
|
|
// CommandRunner runs a command with the ability to kill the process before the timeout.
|
|
type CommandRunner struct {
|
|
cmd *exec.Cmd
|
|
}
|
|
|
|
// Run runs the command.
|
|
func (c *CommandRunner) Run(timeout time.Duration, command []string, buffer io.Reader) error {
|
|
cmd := exec.Command(command[0], command[1:]...)
|
|
cmd.Stdin = buffer
|
|
var stderr bytes.Buffer
|
|
cmd.Stderr = &stderr
|
|
|
|
err := internal.RunTimeout(cmd, timeout)
|
|
s := stderr
|
|
|
|
if err != nil {
|
|
if err == internal.TimeoutErr {
|
|
return fmt.Errorf("%q timed out and was killed", command)
|
|
}
|
|
|
|
if s.Len() > 0 {
|
|
log.Printf("E! [outputs.exec] Command error: %q", truncate(s))
|
|
}
|
|
|
|
if status, ok := internal.ExitStatus(err); ok {
|
|
return fmt.Errorf("%q exited %d with %s", command, status, err.Error())
|
|
}
|
|
|
|
return fmt.Errorf("%q failed with %s", command, err.Error())
|
|
}
|
|
|
|
c.cmd = cmd
|
|
|
|
return nil
|
|
}
|
|
|
|
func truncate(buf bytes.Buffer) string {
|
|
// Limit the number of bytes.
|
|
didTruncate := false
|
|
if buf.Len() > maxStderrBytes {
|
|
buf.Truncate(maxStderrBytes)
|
|
didTruncate = true
|
|
}
|
|
if i := bytes.IndexByte(buf.Bytes(), '\n'); i > 0 {
|
|
// Only show truncation if the newline wasn't the last character.
|
|
if i < buf.Len()-1 {
|
|
didTruncate = true
|
|
}
|
|
buf.Truncate(i)
|
|
}
|
|
if didTruncate {
|
|
buf.WriteString("...")
|
|
}
|
|
return buf.String()
|
|
}
|
|
|
|
func init() {
|
|
outputs.Add("exec", func() telegraf.Output {
|
|
return &Exec{
|
|
runner: &CommandRunner{},
|
|
Timeout: internal.Duration{Duration: time.Second * 5},
|
|
}
|
|
})
|
|
}
|