package bcache import ( "errors" "io/ioutil" "os" "path/filepath" "strconv" "strings" "github.com/influxdata/telegraf" "github.com/influxdata/telegraf/plugins/inputs" ) type Bcache struct { BcachePath string BcacheDevs []string } var sampleConfig = ` ## Bcache sets path ## If not specified, then default is: bcachePath = "/sys/fs/bcache" ## By default, telegraf gather stats for all bcache devices ## Setting devices will restrict the stats to the specified ## bcache devices. bcacheDevs = ["bcache0"] ` func (b *Bcache) SampleConfig() string { return sampleConfig } func (b *Bcache) Description() string { return "Read metrics of bcache from stats_total and dirty_data" } func getTags(bdev string) map[string]string { backingDevFile, _ := os.Readlink(bdev) backingDevPath := strings.Split(backingDevFile, "/") backingDev := backingDevPath[len(backingDevPath)-2] bcacheDevFile, _ := os.Readlink(bdev + "/dev") bcacheDevPath := strings.Split(bcacheDevFile, "/") bcacheDev := bcacheDevPath[len(bcacheDevPath)-1] return map[string]string{"backing_dev": backingDev, "bcache_dev": bcacheDev} } func prettyToBytes(v string) uint64 { var factors = map[string]uint64{ "k": 1 << 10, "M": 1 << 20, "G": 1 << 30, "T": 1 << 40, "P": 1 << 50, "E": 1 << 60, } var factor uint64 factor = 1 prefix := v[len(v)-1 : len(v)] if factors[prefix] != 0 { v = v[:len(v)-1] factor = factors[prefix] } result, _ := strconv.ParseFloat(v, 32) result = result * float64(factor) return uint64(result) } func (b *Bcache) gatherBcache(bdev string, acc telegraf.Accumulator) error { tags := getTags(bdev) metrics, err := filepath.Glob(bdev + "/stats_total/*") if len(metrics) < 0 { return errors.New("Can't read any stats file") } file, err := ioutil.ReadFile(bdev + "/dirty_data") if err != nil { return err } rawValue := strings.TrimSpace(string(file)) value := prettyToBytes(rawValue) fields := make(map[string]interface{}) fields["dirty_data"] = value for _, path := range metrics { key := filepath.Base(path) file, err := ioutil.ReadFile(path) rawValue := strings.TrimSpace(string(file)) if err != nil { return err } if key == "bypassed" { value := prettyToBytes(rawValue) fields[key] = value } else { value, _ := strconv.ParseUint(rawValue, 10, 64) fields[key] = value } } acc.AddFields("bcache", fields, tags) return nil } func (b *Bcache) Gather(acc telegraf.Accumulator) error { bcacheDevsChecked := make(map[string]bool) var restrictDevs bool if len(b.BcacheDevs) != 0 { restrictDevs = true for _, bcacheDev := range b.BcacheDevs { bcacheDevsChecked[bcacheDev] = true } } bcachePath := b.BcachePath if len(bcachePath) == 0 { bcachePath = "/sys/fs/bcache" } bdevs, _ := filepath.Glob(bcachePath + "/*/bdev*") if len(bdevs) < 1 { return errors.New("Can't find any bcache device") } for _, bdev := range bdevs { if restrictDevs { bcacheDev := getTags(bdev)["bcache_dev"] if !bcacheDevsChecked[bcacheDev] { continue } } b.gatherBcache(bdev, acc) } return nil } func init() { inputs.Add("bcache", func() telegraf.Input { return &Bcache{} }) }