21 #include <sys/types.h>
26 // The above block of magic allows us to look up user_hz via _SC_CLK_TCK.
34 func CopyPipeToChan(in io.Reader, out chan string, done chan<- bool) {
35 s := bufio.NewScanner(in)
42 func CopyChanToPipe(in <-chan string, out io.Writer) {
48 func OpenAndReadAll(filename string, log_chan chan<- string) ([]byte, error) {
49 in, err := os.Open(filename)
52 log_chan <- fmt.Sprintf("crunchstat: open %s: %s", filename, err)
58 content, err := ioutil.ReadAll(in)
59 if err != nil && log_chan != nil {
60 log_chan <- fmt.Sprintf("crunchstat: read %s: %s", filename, err)
66 var reportedStatFile map[string]bool
67 var reportedNoStatFile map[string]bool
69 func FindStat(stderr chan<- string, cgroup Cgroup, statgroup string, stat string) string {
70 if reportedStatFile == nil {
71 reportedStatFile = make(map[string]bool)
72 reportedNoStatFile = make(map[string]bool)
76 path = fmt.Sprintf("%s/%s/%s/%s/%s", cgroup.root, statgroup, cgroup.parent, cgroup.cid, stat)
77 if _, err := os.Stat(path); err != nil {
78 path = fmt.Sprintf("%s/%s/%s/%s", cgroup.root, cgroup.parent, cgroup.cid, stat)
80 if _, err := os.Stat(path); err != nil {
81 path = fmt.Sprintf("%s/%s/%s", cgroup.root, statgroup, stat)
83 if _, err := os.Stat(path); err != nil {
84 path = fmt.Sprintf("%s/%s", cgroup.root, stat)
86 if _, err := os.Stat(path); err != nil {
87 if _, ok := reportedNoStatFile[path]; !ok {
88 stderr <- fmt.Sprintf("crunchstat: did not find stats file (root %s, parent %s, cid %s, statgroup %s, stat %s)", cgroup.root, cgroup.parent, cgroup.cid, statgroup, stat)
89 reportedNoStatFile[path] = true
93 if _, ok := reportedStatFile[path]; !ok {
94 stderr <- fmt.Sprintf("crunchstat: reading stats from %s", path)
95 reportedStatFile[path] = true
100 func GetContainerNetStats(stderr chan<- string, cgroup Cgroup) (io.Reader, error) {
101 procsFilename := FindStat(stderr, cgroup, "cpuacct", "cgroup.procs")
102 procsFile, err := os.Open(procsFilename)
104 stderr <- fmt.Sprintf("crunchstat: open %s: %s", procsFilename, err)
107 defer procsFile.Close()
108 reader := bufio.NewScanner(procsFile)
110 taskPid := reader.Text()
111 statsFilename := fmt.Sprintf("/proc/%s/net/dev", taskPid)
112 stats, err := OpenAndReadAll(statsFilename, stderr)
116 return strings.NewReader(string(stats)), nil
118 return nil, errors.New("Could not read stats for any proc in container")
127 var disk map[string]*Disk
129 func DoBlkIoStats(stderr chan<- string, cgroup Cgroup) {
130 blkio_io_service_bytes := FindStat(stderr, cgroup, "blkio", "blkio.io_service_bytes")
131 if blkio_io_service_bytes == "" {
136 disk = make(map[string]*Disk)
139 c, err := os.Open(blkio_io_service_bytes)
141 stderr <- fmt.Sprintf("open %s: %s", blkio_io_service_bytes, err)
145 b := bufio.NewScanner(c)
146 var device, op string
149 if _, err := fmt.Sscanf(string(b.Text()), "%s %s %d", &device, &op, &next); err != nil {
152 if disk[device] == nil {
153 disk[device] = new(Disk)
156 disk[device].last_read = disk[device].next_read
157 disk[device].next_read = next
158 if disk[device].last_read > 0 && (disk[device].next_read != disk[device].last_read) {
159 stderr <- fmt.Sprintf("crunchstat: blkio.io_service_bytes %s read %v", device, disk[device].next_read-disk[device].last_read)
163 disk[device].last_write = disk[device].next_write
164 disk[device].next_write = next
165 if disk[device].last_write > 0 && (disk[device].next_write != disk[device].last_write) {
166 stderr <- fmt.Sprintf("crunchstat: blkio.io_service_bytes %s write %v", device, disk[device].next_write-disk[device].last_write)
172 func DoMemoryStats(stderr chan<- string, cgroup Cgroup) {
173 memory_stat := FindStat(stderr, cgroup, "memory", "memory.stat")
174 if memory_stat == "" {
177 c, err := os.Open(memory_stat)
179 stderr <- fmt.Sprintf("open %s: %s", memory_stat, err)
183 b := bufio.NewScanner(c)
187 if _, err := fmt.Sscanf(string(b.Text()), "%s %d", &stat, &val); err != nil {
191 stderr <- fmt.Sprintf("crunchstat: mem %d rss", val)
196 type NetSample struct {
202 func DoNetworkStats(stderr chan<- string, cgroup Cgroup, lastStat map[string]NetSample) (map[string]NetSample) {
203 sampleTime := time.Now()
204 stats, err := GetContainerNetStats(stderr, cgroup)
205 if err != nil { return lastStat }
208 lastStat = make(map[string]NetSample)
210 scanner := bufio.NewScanner(stats)
211 Iface: for scanner.Scan() {
214 words := bufio.NewScanner(strings.NewReader(scanner.Text()))
215 words.Split(bufio.ScanWords)
221 ifName = strings.TrimRight(word, ":")
223 if _, err := fmt.Sscanf(word, "%d", &rx); err != nil {
227 if _, err := fmt.Sscanf(word, "%d", &tx); err != nil {
233 if ifName == "lo" || ifName == "" || wordIndex != 17 {
234 // Skip loopback interface and lines with wrong format
237 nextSample := NetSample{}
238 nextSample.sampleTime = sampleTime
239 nextSample.txBytes = tx
240 nextSample.rxBytes = rx
242 if lastSample, ok := lastStat[ifName]; ok {
243 interval := nextSample.sampleTime.Sub(lastSample.sampleTime).Seconds()
244 delta = fmt.Sprintf(" -- interval %.4f seconds %d tx %d rx",
246 tx - lastSample.txBytes,
247 rx - lastSample.rxBytes)
249 stderr <- fmt.Sprintf("crunchstat: net:%s %d tx %d rx%s",
250 ifName, tx, rx, delta)
251 lastStat[ifName] = nextSample
256 func PollCgroupStats(cgroup Cgroup, stderr chan string, poll int64, stop_poll_chan <-chan bool) {
257 var last_user int64 = -1
258 var last_sys int64 = -1
259 var last_cpucount int64 = 0
261 user_hz := float64(C.sysconf(C._SC_CLK_TCK))
263 var lastNetStat map[string]NetSample = nil
265 poll_chan := make(chan bool, 1)
267 // Send periodic poll events.
270 time.Sleep(time.Duration(poll) * time.Millisecond)
275 bedtime := time.Now()
277 case <-stop_poll_chan:
280 // Emit stats, then select again.
282 morning := time.Now()
283 elapsed := morning.Sub(bedtime).Seconds()
284 cpuset_cpus := FindStat(stderr, cgroup, "cpuset", "cpuset.cpus")
285 if cpuset_cpus != "" {
286 b, err := OpenAndReadAll(cpuset_cpus, stderr)
288 // cgroup probably gone -- skip other stats too.
291 sp := strings.Split(string(b), ",")
293 for _, v := range sp {
295 n, _ := fmt.Sscanf(v, "%d-%d", &min, &max)
297 cpus += (max - min) + 1
304 cpuacct_stat := FindStat(stderr, cgroup, "cpuacct", "cpuacct.stat")
305 if cpuacct_stat != "" {
306 b, err := OpenAndReadAll(cpuacct_stat, stderr)
308 // Next time around, last_user would
309 // be >1 interval old, so stats will
310 // be incorrect. Start over instead.
313 // cgroup probably gone -- skip other stats too.
318 fmt.Sscanf(string(b), "user %d\nsystem %d", &next_user, &next_sys)
321 if elapsed > 0 && last_user != -1 {
322 delta = fmt.Sprintf(" -- interval %.4f seconds %.4f user %.4f sys",
324 float64(next_user - last_user) / user_hz,
325 float64(next_sys - last_sys) / user_hz)
327 stderr <- fmt.Sprintf("crunchstat: cpu %.4f user %.4f sys %d cpus%s",
328 float64(next_user) / user_hz,
329 float64(next_sys) / user_hz,
332 last_user = next_user
336 DoBlkIoStats(stderr, cgroup)
337 DoMemoryStats(stderr, cgroup)
338 lastNetStat = DoNetworkStats(stderr, cgroup, lastNetStat)
342 func run(logger *log.Logger) error {
347 cgroup_cidfile string
352 flag.StringVar(&cgroup_root, "cgroup-root", "", "Root of cgroup tree")
353 flag.StringVar(&cgroup_parent, "cgroup-parent", "", "Name of container parent under cgroup")
354 flag.StringVar(&cgroup_cidfile, "cgroup-cid", "", "Path to container id file")
355 flag.Int64Var(&wait, "wait", 5, "Maximum time (in seconds) to wait for cid file to show up")
356 flag.Int64Var(&poll, "poll", 1000, "Polling frequency, in milliseconds")
360 if cgroup_root == "" {
361 logger.Fatal("Must provide -cgroup-root")
364 stderr_chan := make(chan string, 1)
365 defer close(stderr_chan)
366 finish_chan := make(chan bool)
367 defer close(finish_chan)
369 go CopyChanToPipe(stderr_chan, os.Stderr)
373 if len(flag.Args()) > 0 {
375 cmd = exec.Command(flag.Args()[0], flag.Args()[1:]...)
377 logger.Print("Running ", flag.Args())
379 // Child process will use our stdin and stdout pipes
380 // (we close our copies below)
382 cmd.Stdout = os.Stdout
384 // Forward SIGINT and SIGTERM to inner process
385 term := make(chan os.Signal, 1)
386 go func(sig <-chan os.Signal) {
388 if cmd.Process != nil {
389 cmd.Process.Signal(catch)
391 logger.Print("caught signal: ", catch)
393 signal.Notify(term, syscall.SIGTERM)
394 signal.Notify(term, syscall.SIGINT)
396 // Funnel stderr through our channel
397 stderr_pipe, err := cmd.StderrPipe()
401 go CopyPipeToChan(stderr_pipe, stderr_chan, finish_chan)
404 if err := cmd.Start(); err != nil {
408 // Close stdin/stdout in this (parent) process
414 var container_id string
415 if cgroup_cidfile != "" {
416 // wait up to 'wait' seconds for the cid file to appear
419 for i = 0; i < time.Duration(wait)*time.Second; i += (100 * time.Millisecond) {
420 cid, err := OpenAndReadAll(cgroup_cidfile, nil)
421 if err == nil && len(cid) > 0 {
423 container_id = string(cid)
426 time.Sleep(100 * time.Millisecond)
429 logger.Printf("Could not read cid file %s", cgroup_cidfile)
433 stop_poll_chan := make(chan bool, 1)
434 cgroup := Cgroup{cgroup_root, cgroup_parent, container_id}
435 go PollCgroupStats(cgroup, stderr_chan, poll, stop_poll_chan)
437 // When the child exits, tell the polling goroutine to stop.
438 defer func() { stop_poll_chan <- true }()
440 // Wait for CopyPipeToChan to consume child's stderr pipe
447 logger := log.New(os.Stderr, "crunchstat: ", 0)
448 if err := run(logger); err != nil {
449 if exiterr, ok := err.(*exec.ExitError); ok {
450 // The program has exited with an exit code != 0
452 // This works on both Unix and
453 // Windows. Although package syscall is
454 // generally platform dependent, WaitStatus is
455 // defined for both Unix and Windows and in
456 // both cases has an ExitStatus() method with
457 // the same signature.
458 if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
459 os.Exit(status.ExitStatus())
462 logger.Fatalf("cmd.Wait: %v", err)