// makeWatchHandler returns a handler for the given watch
func makeWatchHandler(logOutput io.Writer, params interface{}) watch.HandlerFunc {
script := params.(string)
logger := log.New(logOutput, "", log.LstdFlags)
fn := func(idx uint64, data interface{}) {
// Create the command
cmd, err := ExecScript(script)
if err != nil {
logger.Printf("[ERR] agent: Failed to setup watch: %v", err)
return
}
cmd.Env = append(os.Environ(),
"CONSUL_INDEX="+strconv.FormatUint(idx, 10),
)
// Collect the output
output, _ := circbuf.NewBuffer(WatchBufSize)
cmd.Stdout = output
cmd.Stderr = output
// Setup the input
var inp bytes.Buffer
enc := json.NewEncoder(&inp)
if err := enc.Encode(data); err != nil {
logger.Printf("[ERR] agent: Failed to encode data for watch '%s': %v", script, err)
return
}
cmd.Stdin = &inp
// Run the handler
if err := cmd.Run(); err != nil {
logger.Printf("[ERR] agent: Failed to invoke watch handler '%s': %v", script, err)
}
// Get the output, add a message about truncation
outputStr := string(output.Bytes())
if output.TotalWritten() > output.Size() {
outputStr = fmt.Sprintf("Captured %d of %d bytes\n...\n%s",
output.Size(), output.TotalWritten(), outputStr)
}
// Log the output
logger.Printf("[DEBUG] agent: watch handler '%s' output: %s", script, outputStr)
}
return fn
}
// check is invoked periodically to perform the script check
func (c *CheckMonitor) check() {
// Create the command
cmd, err := ExecScript(c.Script)
if err != nil {
c.Logger.Printf("[ERR] agent: failed to setup invoke '%s': %s", c.Script, err)
c.Notify.UpdateCheck(c.CheckID, structs.HealthCritical, err.Error())
return
}
// Collect the output
output, _ := circbuf.NewBuffer(CheckBufSize)
cmd.Stdout = output
cmd.Stderr = output
// Start the check
if err := cmd.Start(); err != nil {
c.Logger.Printf("[ERR] agent: failed to invoke '%s': %s", c.Script, err)
c.Notify.UpdateCheck(c.CheckID, structs.HealthCritical, err.Error())
return
}
// Wait for the check to complete
errCh := make(chan error, 2)
go func() {
errCh <- cmd.Wait()
}()
go func() {
time.Sleep(30 * time.Second)
errCh <- fmt.Errorf("Timed out running check '%s'", c.Script)
}()
err = <-errCh
// Get the output, add a message about truncation
outputStr := string(output.Bytes())
if output.TotalWritten() > output.Size() {
outputStr = fmt.Sprintf("Captured %d of %d bytes\n...\n%s",
output.Size(), output.TotalWritten(), outputStr)
}
c.Logger.Printf("[DEBUG] agent: check '%s' script '%s' output: %s",
c.CheckID, c.Script, outputStr)
// Check if the check passed
if err == nil {
c.Logger.Printf("[DEBUG] agent: Check '%v' is passing", c.CheckID)
c.Notify.UpdateCheck(c.CheckID, structs.HealthPassing, outputStr)
return
}
// If the exit code is 1, set check as warning
exitErr, ok := err.(*exec.ExitError)
if ok {
if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
code := status.ExitStatus()
if code == 1 {
c.Logger.Printf("[WARN] agent: Check '%v' is now warning", c.CheckID)
c.Notify.UpdateCheck(c.CheckID, structs.HealthWarning, outputStr)
return
}
}
}
// Set the health as critical
c.Logger.Printf("[WARN] agent: Check '%v' is now critical", c.CheckID)
c.Notify.UpdateCheck(c.CheckID, structs.HealthCritical, outputStr)
}