package main import ( "fmt" "io/ioutil" "os" "os/exec" "strings" "time" "github.com/tidwall/gjson" ) // JSONCache caching json type JSONCache struct { JSON gjson.Result LastCollect time.Time } var ( jsonCache map[string]JSONCache ) func init() { jsonCache = make(map[string]JSONCache) } // Parse json to gjson object func parseJSON(data string) gjson.Result { if !gjson.Valid(data) { return gjson.Parse("{}") } return gjson.Parse(data) } // Reading fake smartctl json func readFakeSMARTctl(device string) gjson.Result { s := strings.Split(device, "/") filename := fmt.Sprintf("debug/%s.json", s[len(s)-1]) logger.Verbose("Read fake S.M.A.R.T. data from json: %s", filename) jsonFile, err := ioutil.ReadFile(filename) if err != nil { logger.Error("Fake S.M.A.R.T. data reading error: %s", err) return parseJSON("{}") } return parseJSON(string(jsonFile)) } // Get json from smartctl and parse it func readSMARTctl(device string) (gjson.Result, bool) { logger.Debug("Collecting S.M.A.R.T. counters, device: %s", device) out, err := exec.Command(options.SMARTctl.SMARTctlLocation, "--json", "--xall", device).Output() if err != nil { logger.Warning("S.M.A.R.T. output reading error: %s", err) } json := parseJSON(string(out)) rcOk := resultCodeIsOk(json.Get("smartctl.exit_status").Int()) jsonOk := jsonIsOk(json) return json, rcOk && jsonOk } func readSMARTctlDevices() gjson.Result { logger.Debug("Collecting devices") out, err := exec.Command(options.SMARTctl.SMARTctlLocation, "--json", "--scan-open").Output() if err != nil { logger.Warning("S.M.A.R.T. output reading error: %s", err) } return parseJSON(string(out)) } // Select json source and parse func readData(device string) (gjson.Result, error) { if options.SMARTctl.FakeJSON { return readFakeSMARTctl(device), nil } if _, err := os.Stat(device); err == nil { cacheValue, cacheOk := jsonCache[device] timeToScan := false if cacheOk { timeToScan = time.Now().After(cacheValue.LastCollect.Add(options.SMARTctl.CollectPeriodDuration)) } else { timeToScan = true } if timeToScan { json, ok := readSMARTctl(device) if ok { jsonCache[device] = JSONCache{JSON: json, LastCollect: time.Now()} return jsonCache[device].JSON, nil } return gjson.Parse("{}"), fmt.Errorf("smartctl returned bad data for device %s", device) } return gjson.Parse("{}"), fmt.Errorf("Too early collect called for device %s", device) } return gjson.Parse("{}"), fmt.Errorf("Device %s unavialable", device) } // Parse smartctl return code func resultCodeIsOk(SMARTCtlResult int64) bool { result := true if SMARTCtlResult > 0 { bits := fmt.Sprintf("%08b", SMARTCtlResult) // logger.Debug("Return code: %d: %s", SMARTCtlResult, bits) if bits[0] == '1' { logger.Error("Command line did not parse.") result = false } if bits[1] == '1' { logger.Error("Device open failed, device did not return an IDENTIFY DEVICE structure, or device is in a low-power mode") result = false } if bits[2] == '1' { logger.Warning("Some SMART or other ATA command to the disk failed, or there was a checksum error in a SMART data structure") } if bits[3] == '1' { logger.Warning("SMART status check returned 'DISK FAILING'.") } if bits[4] == '1' { logger.Warning("We found prefail Attributes <= threshold.") } if bits[5] == '1' { logger.Warning("SMART status check returned 'DISK OK' but we found that some (usage or prefail) Attributes have been <= threshold at some time in the past.") } if bits[6] == '1' { logger.Warning("The device error log contains records of errors.") } if bits[7] == '1' { logger.Warning("The device self-test log contains records of errors. [ATA only] Failed self-tests outdated by a newer successful extended self-test are ignored.") } } return result } // Check json func jsonIsOk(json gjson.Result) bool { messages := json.Get("smartctl.messages") // logger.Debug(messages.String()) if messages.Exists() { for _, message := range messages.Array() { if message.Get("severity").String() == "error" { logger.Error(message.Get("string").String()) return false } } } return true }