package cgroups import ( "bufio" "fmt" "os" "path/filepath" "strconv" "strings" spec "github.com/opencontainers/runtime-spec/specs-go" "github.com/pkg/errors" ) type blkioHandler struct { } func getBlkioHandler() *blkioHandler { return &blkioHandler{} } // Apply set the specified constraints func (c *blkioHandler) Apply(ctr *CgroupControl, res *spec.LinuxResources) error { if res.BlockIO == nil { return nil } return fmt.Errorf("blkio apply function not implemented yet") } // Create the cgroup func (c *blkioHandler) Create(ctr *CgroupControl) (bool, error) { if ctr.cgroup2 { return false, fmt.Errorf("io create not implemented for cgroup v2") } return ctr.createCgroupDirectory(Blkio) } // Destroy the cgroup func (c *blkioHandler) Destroy(ctr *CgroupControl) error { return os.Remove(ctr.getCgroupv1Path(Blkio)) } // Stat fills a metrics structure with usage stats for the controller func (c *blkioHandler) Stat(ctr *CgroupControl, m *Metrics) error { var ioServiceBytesRecursive []BlkIOEntry if ctr.cgroup2 { // more details on the io.stat file format:X https://facebookmicrosites.github.io/cgroup2/docs/io-controller.html values, err := readCgroup2MapFile(ctr, "io.stat") if err != nil { return err } for k, v := range values { d := strings.Split(k, ":") if len(d) != 2 { continue } minor, err := strconv.ParseUint(d[0], 10, 0) if err != nil { return err } major, err := strconv.ParseUint(d[1], 10, 0) if err != nil { return err } for _, item := range v { d := strings.Split(item, "=") if len(d) != 2 { continue } op := d[0] // Accommodate the cgroup v1 naming switch op { case "rbytes": op = "read" case "wbytes": op = "write" } value, err := strconv.ParseUint(d[1], 10, 0) if err != nil { return err } entry := BlkIOEntry{ Op: op, Major: major, Minor: minor, Value: value, } ioServiceBytesRecursive = append(ioServiceBytesRecursive, entry) } } } else { BlkioRoot := ctr.getCgroupv1Path(Blkio) p := filepath.Join(BlkioRoot, "blkio.throttle.io_service_bytes_recursive") f, err := os.Open(p) if err != nil { if os.IsNotExist(err) { return nil } return errors.Wrapf(err, "open %s", p) } defer f.Close() scanner := bufio.NewScanner(f) for scanner.Scan() { line := scanner.Text() parts := strings.Fields(line) if len(parts) < 3 { continue } d := strings.Split(parts[0], ":") if len(d) != 2 { continue } minor, err := strconv.ParseUint(d[0], 10, 0) if err != nil { return err } major, err := strconv.ParseUint(d[1], 10, 0) if err != nil { return err } op := parts[1] value, err := strconv.ParseUint(parts[2], 10, 0) if err != nil { return err } entry := BlkIOEntry{ Op: op, Major: major, Minor: minor, Value: value, } ioServiceBytesRecursive = append(ioServiceBytesRecursive, entry) } if err := scanner.Err(); err != nil { return errors.Wrapf(err, "parse %s", p) } } m.Blkio = BlkioMetrics{IoServiceBytesRecursive: ioServiceBytesRecursive} return nil }