package exec import ( "bytes" "fmt" "os/exec" "path/filepath" "runtime" "strings" "sync" "time" "github.com/kballard/go-shellquote" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/internal" "github.com/influxdata/telegraf/plugins/inputs" "github.com/influxdata/telegraf/plugins/parsers" "github.com/influxdata/telegraf/plugins/parsers/nagios" ) const sampleConfig = ` ## Commands array commands = [ "/tmp/test.sh", "/usr/bin/mycollector --foo=bar", "/tmp/collect_*.sh" ] ## Timeout for each command to complete. timeout = "5s" ## measurement name suffix (for separating different commands) name_suffix = "_mycollector" ## 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" ` const MaxStderrBytes = 512 type Exec struct { Commands []string Command string Timeout internal.Duration parser parsers.Parser runner Runner log telegraf.Logger } func NewExec() *Exec { return &Exec{ runner: CommandRunner{}, Timeout: internal.Duration{Duration: time.Second * 5}, } } type Runner interface { Run(string, time.Duration) ([]byte, []byte, error) } type CommandRunner struct{} func (c CommandRunner) Run( command string, timeout time.Duration, ) ([]byte, []byte, error) { split_cmd, err := shellquote.Split(command) if err != nil || len(split_cmd) == 0 { return nil, nil, fmt.Errorf("exec: unable to parse command, %s", err) } cmd := exec.Command(split_cmd[0], split_cmd[1:]...) var ( out bytes.Buffer stderr bytes.Buffer ) cmd.Stdout = &out cmd.Stderr = &stderr runErr := internal.RunTimeout(cmd, timeout) out = removeCarriageReturns(out) if stderr.Len() > 0 { stderr = removeCarriageReturns(stderr) stderr = truncate(stderr) } return out.Bytes(), stderr.Bytes(), runErr } func truncate(buf bytes.Buffer) bytes.Buffer { // 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 } // removeCarriageReturns removes all carriage returns from the input if the // OS is Windows. It does not return any errors. func removeCarriageReturns(b bytes.Buffer) bytes.Buffer { if runtime.GOOS == "windows" { var buf bytes.Buffer for { byt, er := b.ReadBytes(0x0D) end := len(byt) if nil == er { end -= 1 } if nil != byt { buf.Write(byt[:end]) } else { break } if nil != er { break } } b = buf } return b } func (e *Exec) ProcessCommand(command string, acc telegraf.Accumulator, wg *sync.WaitGroup) { defer wg.Done() _, isNagios := e.parser.(*nagios.NagiosParser) out, errbuf, runErr := e.runner.Run(command, e.Timeout.Duration) if !isNagios && runErr != nil { err := fmt.Errorf("exec: %s for command '%s': %s", runErr, command, string(errbuf)) acc.AddError(err) return } metrics, err := e.parser.Parse(out) if err != nil { acc.AddError(err) return } if isNagios { metrics, err = nagios.TryAddState(runErr, metrics) if err != nil { e.log.Errorf("failed to add nagios state: %s", err) } } for _, m := range metrics { acc.AddMetric(m) } } func (e *Exec) SampleConfig() string { return sampleConfig } func (e *Exec) Description() string { return "Read metrics from one or more commands that can output to stdout" } func (e *Exec) SetParser(parser parsers.Parser) { e.parser = parser } func (e *Exec) Gather(acc telegraf.Accumulator) error { var wg sync.WaitGroup // Legacy single command support if e.Command != "" { e.Commands = append(e.Commands, e.Command) e.Command = "" } commands := make([]string, 0, len(e.Commands)) for _, pattern := range e.Commands { cmdAndArgs := strings.SplitN(pattern, " ", 2) if len(cmdAndArgs) == 0 { continue } matches, err := filepath.Glob(cmdAndArgs[0]) if err != nil { acc.AddError(err) continue } if len(matches) == 0 { // There were no matches with the glob pattern, so let's assume // that the command is in PATH and just run it as it is commands = append(commands, pattern) } else { // There were matches, so we'll append each match together with // the arguments to the commands slice for _, match := range matches { if len(cmdAndArgs) == 1 { commands = append(commands, match) } else { commands = append(commands, strings.Join([]string{match, cmdAndArgs[1]}, " ")) } } } } wg.Add(len(commands)) for _, command := range commands { go e.ProcessCommand(command, acc, &wg) } wg.Wait() return nil } func (e *Exec) Init() error { return nil } func init() { inputs.Add("exec", func() telegraf.Input { return NewExec() }) }