10666: Added version number to go sdk and go tools & services
[arvados.git] / services / crunchstat / crunchstat.go
index 9590bbbf5c42a6e0fa8b4b6032a1ae9715d5daa7..454a5fc3a4363d24b6f858183da6d404750ea6a1 100644 (file)
+// Copyright (C) The Arvados Authors. All rights reserved.
+//
+// SPDX-License-Identifier: AGPL-3.0
+
 package main
 
 import (
        "bufio"
-       "bytes"
        "flag"
-       "errors"
        "fmt"
        "io"
-       "io/ioutil"
        "log"
        "os"
        "os/exec"
        "os/signal"
-       "strings"
        "syscall"
        "time"
-)
 
-/*
-#include <unistd.h>
-#include <sys/types.h>
-#include <pwd.h>
-#include <stdlib.h>
-*/
-import "C"
-// The above block of magic allows us to look up user_hz via _SC_CLK_TCK.
-
-type Cgroup struct {
-       root   string
-       parent string
-       cid    string
-}
+       "git.curoverse.com/arvados.git/lib/crunchstat"
+       arvadosVersion "git.curoverse.com/arvados.git/sdk/go/version"
+)
 
-func CopyPipeToChan(in io.Reader, out chan string, done chan<- bool) {
-       s := bufio.NewScanner(in)
-       for s.Scan() {
-               out <- s.Text()
-       }
-       done <- true
-}
+const MaxLogLine = 1 << 14 // Child stderr lines >16KiB will be split
 
-func CopyChanToPipe(in <-chan string, out io.Writer) {
-       for s := range in {
-               fmt.Fprintln(out, s)
-       }
-}
+var (
+       signalOnDeadPPID  int = 15
+       ppidCheckInterval     = time.Second
+)
 
-func OpenAndReadAll(filename string, log_chan chan<- string) ([]byte, error) {
-       in, err := os.Open(filename)
-       if err != nil {
-               if log_chan != nil {
-                       log_chan <- fmt.Sprintf("crunchstat: open %s: %s", filename, err)
-               }
-               return nil, err
-       }
-       defer in.Close()
-       {
-               content, err := ioutil.ReadAll(in)
-               if err != nil && log_chan != nil {
-                       log_chan <- fmt.Sprintf("crunchstat: read %s: %s", filename, err)
-               }
-               return content, err
+func main() {
+       reporter := crunchstat.Reporter{
+               Logger: log.New(os.Stderr, "crunchstat: ", 0),
        }
-}
 
-var reportedStatFile map[string]bool
-var reportedNoStatFile map[string]bool
+       flag.StringVar(&reporter.CgroupRoot, "cgroup-root", "", "Root of cgroup tree")
+       flag.StringVar(&reporter.CgroupParent, "cgroup-parent", "", "Name of container parent under cgroup")
+       flag.StringVar(&reporter.CIDFile, "cgroup-cid", "", "Path to container id file")
+       flag.IntVar(&signalOnDeadPPID, "signal-on-dead-ppid", signalOnDeadPPID, "Signal to send child if crunchstat's parent process disappears (0 to disable)")
+       flag.DurationVar(&ppidCheckInterval, "ppid-check-interval", ppidCheckInterval, "Time between checks for parent process disappearance")
+       pollMsec := flag.Int64("poll", 1000, "Reporting interval, in milliseconds")
+       getVersion := flag.Bool("version", false, "Print version information and exit.")
 
-func FindStat(stderr chan<- string, cgroup Cgroup, statgroup string, stat string) string {
-       if reportedStatFile == nil {
-               reportedStatFile = make(map[string]bool)
-               reportedNoStatFile = make(map[string]bool)
-       }
-
-       var path string
-       path = fmt.Sprintf("%s/%s/%s/%s/%s", cgroup.root, statgroup, cgroup.parent, cgroup.cid, stat)
-       if _, err := os.Stat(path); err != nil {
-               path = fmt.Sprintf("%s/%s/%s/%s", cgroup.root, cgroup.parent, cgroup.cid, stat)
-       }
-       if _, err := os.Stat(path); err != nil {
-               path = fmt.Sprintf("%s/%s/%s", cgroup.root, statgroup, stat)
-       }
-       if _, err := os.Stat(path); err != nil {
-               path = fmt.Sprintf("%s/%s", cgroup.root, stat)
-       }
-       if _, err := os.Stat(path); err != nil {
-               if _, ok := reportedNoStatFile[stat]; !ok {
-                       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)
-                       reportedNoStatFile[stat] = true
-               }
-               return ""
-       }
-       if _, ok := reportedStatFile[path]; !ok {
-               stderr <- fmt.Sprintf("crunchstat: reading stats from %s", path)
-               reportedStatFile[path] = true
-       }
-       return path
-}
+       flag.Parse()
 
-func GetContainerNetStats(stderr chan<- string, cgroup Cgroup) (io.Reader, error) {
-       procsFilename := FindStat(stderr, cgroup, "cpuacct", "cgroup.procs")
-       procsFile, err := os.Open(procsFilename)
-       if err != nil {
-               stderr <- fmt.Sprintf("crunchstat: open %s: %s", procsFilename, err)
-               return nil, err
+       // Print version information if requested
+       if *getVersion {
+               fmt.Printf("Version: %s\n", arvadosVersion.GetVersion())
+               os.Exit(0)
        }
-       defer procsFile.Close()
-       reader := bufio.NewScanner(procsFile)
-       for reader.Scan() {
-               taskPid := reader.Text()
-               statsFilename := fmt.Sprintf("/proc/%s/net/dev", taskPid)
-               stats, err := OpenAndReadAll(statsFilename, stderr)
-               if err != nil {
-                       continue
-               }
-               return strings.NewReader(string(stats)), nil
-       }
-       return nil, errors.New("Could not read stats for any proc in container")
-}
 
-type IoSample struct {
-       sampleTime time.Time
-       txBytes    int64
-       rxBytes    int64
-}
+       reporter.Logger.Printf("crunchstat %q started", arvadosVersion.GetVersion())
 
-func DoBlkIoStats(stderr chan<- string, cgroup Cgroup, lastSample map[string]IoSample) (map[string]IoSample) {
-       blkio_io_service_bytes := FindStat(stderr, cgroup, "blkio", "blkio.io_service_bytes")
-       if blkio_io_service_bytes == "" {
-               return lastSample
+       if reporter.CgroupRoot == "" {
+               reporter.Logger.Fatal("error: must provide -cgroup-root")
+       } else if signalOnDeadPPID < 0 {
+               reporter.Logger.Fatalf("-signal-on-dead-ppid=%d is invalid (use a positive signal number, or 0 to disable)", signalOnDeadPPID)
        }
+       reporter.PollPeriod = time.Duration(*pollMsec) * time.Millisecond
 
-       c, err := os.Open(blkio_io_service_bytes)
-       if err != nil {
-               stderr <- fmt.Sprintf("crunchstat: open %s: %s", blkio_io_service_bytes, err)
-               return lastSample
-       }
-       defer c.Close()
-       b := bufio.NewScanner(c)
-       var sampleTime = time.Now()
-       newSamples := make(map[string]IoSample)
-       for b.Scan() {
-               var device, op string
-               var val int64
-               if _, err := fmt.Sscanf(string(b.Text()), "%s %s %d", &device, &op, &val); err != nil {
-                       continue
-               }
-               var thisSample IoSample
-               var ok bool
-               if thisSample, ok = newSamples[device]; !ok {
-                       thisSample = IoSample{sampleTime, -1, -1}
-               }
-               switch op {
-               case "Read":
-                       thisSample.rxBytes = val
-               case "Write":
-                       thisSample.txBytes = val
-               }
-               newSamples[device] = thisSample
-       }
-       if lastSample == nil {
-               lastSample = make(map[string]IoSample)
-       }
-       for dev, sample := range newSamples {
-               if sample.txBytes < 0 || sample.rxBytes < 0 {
-                       continue
-               }
-               delta := ""
-               if prev, ok := lastSample[dev]; ok {
-                       delta = fmt.Sprintf(" -- interval %.4f seconds %d write %d read",
-                               sample.sampleTime.Sub(prev.sampleTime).Seconds(),
-                               sample.txBytes - prev.txBytes,
-                               sample.rxBytes - prev.rxBytes)
-               }
-               stderr <- fmt.Sprintf("crunchstat: blkio:%s %d write %d read%s", dev, sample.txBytes, sample.rxBytes, delta)
-               lastSample[dev] = sample
-       }
-       return lastSample
-}
-
-type MemSample struct {
-       sampleTime time.Time
-       memStat    map[string]int64
-}
-
-func DoMemoryStats(stderr chan<- string, cgroup Cgroup) {
-       memory_stat := FindStat(stderr, cgroup, "memory", "memory.stat")
-       if memory_stat == "" {
-               return
-       }
-       c, err := os.Open(memory_stat)
-       if err != nil {
-               stderr <- fmt.Sprintf("crunchstat: open %s: %s", memory_stat, err)
-               return
-       }
-       defer c.Close()
-       b := bufio.NewScanner(c)
-       thisSample := MemSample{time.Now(), make(map[string]int64)}
-       wantStats := [...]string{"cache", "pgmajfault", "rss"}
-       for b.Scan() {
-               var stat string
-               var val int64
-               if _, err := fmt.Sscanf(string(b.Text()), "%s %d", &stat, &val); err != nil {
-                       continue
-               }
-               thisSample.memStat[stat] = val
-       }
-       var outstat bytes.Buffer
-       for _, key := range wantStats {
-               if val, ok := thisSample.memStat[key]; ok {
-                       outstat.WriteString(fmt.Sprintf(" %d %s", val, key))
-               }
-       }
-       stderr <- fmt.Sprintf("crunchstat: mem%s", outstat.String())
-}
+       reporter.Start()
+       err := runCommand(flag.Args(), reporter.Logger)
+       reporter.Stop()
 
-func DoNetworkStats(stderr chan<- string, cgroup Cgroup, lastSample map[string]IoSample) (map[string]IoSample) {
-       sampleTime := time.Now()
-       stats, err := GetContainerNetStats(stderr, cgroup)
-       if err != nil { return lastSample }
+       if err, ok := err.(*exec.ExitError); ok {
+               // The program has exited with an exit code != 0
 
-       if lastSample == nil {
-               lastSample = make(map[string]IoSample)
-       }
-       scanner := bufio.NewScanner(stats)
-       Iface: for scanner.Scan() {
-               var ifName string
-               var rx, tx int64
-               words := bufio.NewScanner(strings.NewReader(scanner.Text()))
-               words.Split(bufio.ScanWords)
-               wordIndex := 0
-               for words.Scan() {
-                       word := words.Text()
-                       switch wordIndex {
-                       case 0:
-                               ifName = strings.TrimRight(word, ":")
-                       case 1:
-                               if _, err := fmt.Sscanf(word, "%d", &rx); err != nil {
-                                       continue Iface
-                               }
-                       case 9:
-                               if _, err := fmt.Sscanf(word, "%d", &tx); err != nil {
-                                       continue Iface
-                               }
-                       }
-                       wordIndex++
-               }
-               if ifName == "lo" || ifName == "" || wordIndex != 17 {
-                       // Skip loopback interface and lines with wrong format
-                       continue
-               }
-               nextSample := IoSample{}
-               nextSample.sampleTime = sampleTime
-               nextSample.txBytes = tx
-               nextSample.rxBytes = rx
-               var delta string
-               if lastSample, ok := lastSample[ifName]; ok {
-                       interval := nextSample.sampleTime.Sub(lastSample.sampleTime).Seconds()
-                       delta = fmt.Sprintf(" -- interval %.4f seconds %d tx %d rx",
-                               interval,
-                               tx - lastSample.txBytes,
-                               rx - lastSample.rxBytes)
+               // This works on both Unix and Windows. Although
+               // package syscall is generally platform dependent,
+               // WaitStatus is defined for both Unix and Windows and
+               // in both cases has an ExitStatus() method with the
+               // same signature.
+               if status, ok := err.Sys().(syscall.WaitStatus); ok {
+                       os.Exit(status.ExitStatus())
+               } else {
+                       reporter.Logger.Fatalln("ExitError without WaitStatus:", err)
                }
-               stderr <- fmt.Sprintf("crunchstat: net:%s %d tx %d rx%s",
-                       ifName, tx, rx, delta)
-               lastSample[ifName] = nextSample
+       } else if err != nil {
+               reporter.Logger.Fatalln("error in cmd.Wait:", err)
        }
-       return lastSample
 }
 
-func PollCgroupStats(cgroup Cgroup, stderr chan string, poll int64, stop_poll_chan <-chan bool) {
-       var last_user int64 = -1
-       var last_sys int64 = -1
-       var last_cpucount int64 = 0
+func runCommand(argv []string, logger *log.Logger) error {
+       cmd := exec.Command(argv[0], argv[1:]...)
 
-       user_hz := float64(C.sysconf(C._SC_CLK_TCK))
+       logger.Println("Running", argv)
 
-       var lastNetSample map[string]IoSample = nil
-       var lastDiskSample map[string]IoSample = nil
+       // Child process will use our stdin and stdout pipes
+       // (we close our copies below)
+       cmd.Stdin = os.Stdin
+       cmd.Stdout = os.Stdout
 
-       poll_chan := make(chan bool, 1)
-       go func() {
-               // Send periodic poll events.
-               poll_chan <- true
-               for {
-                       time.Sleep(time.Duration(poll) * time.Millisecond)
-                       poll_chan <- true
-               }
-       }()
-       for {
-               bedtime := time.Now()
-               select {
-               case <-stop_poll_chan:
-                       return
-               case <-poll_chan:
-                       // Emit stats, then select again.
-               }
-               morning := time.Now()
-               elapsed := morning.Sub(bedtime).Seconds()
-               cpuset_cpus := FindStat(stderr, cgroup, "cpuset", "cpuset.cpus")
-               if cpuset_cpus != "" {
-                       b, err := OpenAndReadAll(cpuset_cpus, stderr)
-                       if err != nil {
-                               // cgroup probably gone -- skip other stats too.
-                               continue
-                       }
-                       sp := strings.Split(string(b), ",")
-                       cpus := int64(0)
-                       for _, v := range sp {
-                               var min, max int64
-                               n, _ := fmt.Sscanf(v, "%d-%d", &min, &max)
-                               if n == 2 {
-                                       cpus += (max - min) + 1
-                               } else {
-                                       cpus += 1
-                               }
-                       }
-                       last_cpucount = cpus
-               }
-               cpuacct_stat := FindStat(stderr, cgroup, "cpuacct", "cpuacct.stat")
-               if cpuacct_stat != "" {
-                       b, err := OpenAndReadAll(cpuacct_stat, stderr)
-                       if err != nil {
-                               // Next time around, last_user would
-                               // be >1 interval old, so stats will
-                               // be incorrect. Start over instead.
-                               last_user = -1
-
-                               // cgroup probably gone -- skip other stats too.
-                               continue
-                       }
-                       var next_user int64
-                       var next_sys int64
-                       fmt.Sscanf(string(b), "user %d\nsystem %d", &next_user, &next_sys)
-
-                       delta := ""
-                       if elapsed > 0 && last_user != -1 {
-                               delta = fmt.Sprintf(" -- interval %.4f seconds %.4f user %.4f sys",
-                                       elapsed,
-                                       float64(next_user - last_user) / user_hz,
-                                       float64(next_sys - last_sys) / user_hz)
-                       }
-                       stderr <- fmt.Sprintf("crunchstat: cpu %.4f user %.4f sys %d cpus%s",
-                               float64(next_user) / user_hz,
-                               float64(next_sys) / user_hz,
-                               last_cpucount,
-                               delta)
-                       last_user = next_user
-                       last_sys = next_sys
+       // Forward SIGINT and SIGTERM to child process
+       sigChan := make(chan os.Signal, 1)
+       go func(sig <-chan os.Signal) {
+               catch := <-sig
+               if cmd.Process != nil {
+                       cmd.Process.Signal(catch)
                }
+               logger.Println("notice: caught signal:", catch)
+       }(sigChan)
+       signal.Notify(sigChan, syscall.SIGTERM)
+       signal.Notify(sigChan, syscall.SIGINT)
 
-               DoMemoryStats(stderr, cgroup)
-               lastDiskSample = DoBlkIoStats(stderr, cgroup, lastDiskSample)
-               lastNetSample = DoNetworkStats(stderr, cgroup, lastNetSample)
+       // Kill our child proc if our parent process disappears
+       if signalOnDeadPPID != 0 {
+               go sendSignalOnDeadPPID(ppidCheckInterval, signalOnDeadPPID, os.Getppid(), cmd, logger)
        }
-}
-
-func run(logger *log.Logger) error {
-
-       var (
-               cgroup_root    string
-               cgroup_parent  string
-               cgroup_cidfile string
-               wait           int64
-               poll           int64
-       )
-
-       flag.StringVar(&cgroup_root, "cgroup-root", "", "Root of cgroup tree")
-       flag.StringVar(&cgroup_parent, "cgroup-parent", "", "Name of container parent under cgroup")
-       flag.StringVar(&cgroup_cidfile, "cgroup-cid", "", "Path to container id file")
-       flag.Int64Var(&wait, "wait", 5, "Maximum time (in seconds) to wait for cid file to show up")
-       flag.Int64Var(&poll, "poll", 1000, "Polling frequency, in milliseconds")
-
-       flag.Parse()
 
-       if cgroup_root == "" {
-               logger.Fatal("Must provide -cgroup-root")
+       // Funnel stderr through our channel
+       stderr_pipe, err := cmd.StderrPipe()
+       if err != nil {
+               logger.Fatalln("error in StderrPipe:", err)
        }
 
-       stderr_chan := make(chan string, 1)
-       defer close(stderr_chan)
-       finish_chan := make(chan bool)
-       defer close(finish_chan)
-
-       go CopyChanToPipe(stderr_chan, os.Stderr)
-
-       var cmd *exec.Cmd
-
-       if len(flag.Args()) > 0 {
-               // Set up subprocess
-               cmd = exec.Command(flag.Args()[0], flag.Args()[1:]...)
-
-               logger.Print("Running ", flag.Args())
+       // Run subprocess
+       if err := cmd.Start(); err != nil {
+               logger.Fatalln("error in cmd.Start:", err)
+       }
 
-               // Child process will use our stdin and stdout pipes
-               // (we close our copies below)
-               cmd.Stdin = os.Stdin
-               cmd.Stdout = os.Stdout
+       // Close stdin/stdout in this (parent) process
+       os.Stdin.Close()
+       os.Stdout.Close()
 
-               // Forward SIGINT and SIGTERM to inner process
-               term := make(chan os.Signal, 1)
-               go func(sig <-chan os.Signal) {
-                       catch := <-sig
-                       if cmd.Process != nil {
-                               cmd.Process.Signal(catch)
-                       }
-                       logger.Print("caught signal: ", catch)
-               }(term)
-               signal.Notify(term, syscall.SIGTERM)
-               signal.Notify(term, syscall.SIGINT)
+       copyPipeToChildLog(stderr_pipe, log.New(os.Stderr, "", 0))
 
-               // Funnel stderr through our channel
-               stderr_pipe, err := cmd.StderrPipe()
-               if err != nil {
-                       logger.Fatal(err)
-               }
-               go CopyPipeToChan(stderr_pipe, stderr_chan, finish_chan)
+       return cmd.Wait()
+}
 
-               // Run subprocess
-               if err := cmd.Start(); err != nil {
-                       logger.Fatal(err)
+func sendSignalOnDeadPPID(intvl time.Duration, signum, ppidOrig int, cmd *exec.Cmd, logger *log.Logger) {
+       ticker := time.NewTicker(intvl)
+       for range ticker.C {
+               ppid := os.Getppid()
+               if ppid == ppidOrig {
+                       continue
                }
-
-               // Close stdin/stdout in this (parent) process
-               os.Stdin.Close()
-               os.Stdout.Close()
-       }
-
-       // Read the cid file
-       var container_id string
-       if cgroup_cidfile != "" {
-               // wait up to 'wait' seconds for the cid file to appear
-               ok := false
-               var i time.Duration
-               for i = 0; i < time.Duration(wait)*time.Second; i += (100 * time.Millisecond) {
-                       cid, err := OpenAndReadAll(cgroup_cidfile, nil)
-                       if err == nil && len(cid) > 0 {
-                               ok = true
-                               container_id = string(cid)
-                               break
-                       }
-                       time.Sleep(100 * time.Millisecond)
+               if cmd.Process == nil {
+                       // Child process isn't running yet
+                       continue
                }
-               if !ok {
-                       logger.Printf("Could not read cid file %s", cgroup_cidfile)
+               logger.Printf("notice: crunchstat ppid changed from %d to %d -- killing child pid %d with signal %d", ppidOrig, ppid, cmd.Process.Pid, signum)
+               err := cmd.Process.Signal(syscall.Signal(signum))
+               if err != nil {
+                       logger.Printf("error: sending signal: %s", err)
+                       continue
                }
+               ticker.Stop()
+               break
        }
-
-       stop_poll_chan := make(chan bool, 1)
-       cgroup := Cgroup{cgroup_root, cgroup_parent, container_id}
-       go PollCgroupStats(cgroup, stderr_chan, poll, stop_poll_chan)
-
-       // When the child exits, tell the polling goroutine to stop.
-       defer func() { stop_poll_chan <- true }()
-
-       // Wait for CopyPipeToChan to consume child's stderr pipe
-       <-finish_chan
-
-       return cmd.Wait()
 }
 
-func main() {
-       logger := log.New(os.Stderr, "crunchstat: ", 0)
-       if err := run(logger); err != nil {
-               if exiterr, ok := err.(*exec.ExitError); ok {
-                       // The program has exited with an exit code != 0
-
-                       // This works on both Unix and
-                       // Windows. Although package syscall is
-                       // generally platform dependent, WaitStatus is
-                       // defined for both Unix and Windows and in
-                       // both cases has an ExitStatus() method with
-                       // the same signature.
-                       if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
-                               os.Exit(status.ExitStatus())
-                       }
+func copyPipeToChildLog(in io.ReadCloser, logger *log.Logger) {
+       reader := bufio.NewReaderSize(in, MaxLogLine)
+       var prefix string
+       for {
+               line, isPrefix, err := reader.ReadLine()
+               if err == io.EOF {
+                       break
+               } else if err != nil {
+                       logger.Fatal("error reading child stderr:", err)
+               }
+               var suffix string
+               if isPrefix {
+                       suffix = "[...]"
+               }
+               logger.Print(prefix, string(line), suffix)
+               // Set up prefix for following line
+               if isPrefix {
+                       prefix = "[...]"
                } else {
-                       logger.Fatalf("cmd.Wait: %v", err)
+                       prefix = ""
                }
        }
+       in.Close()
 }