all: Add Prometheus-style metrics to expose some internal performance counters (fixes #5175) (#9003)

This commit is contained in:
Jakob Borg 2023-08-04 19:57:30 +02:00 committed by GitHub
parent 58042b3129
commit b9c08d3814
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
25 changed files with 945 additions and 53 deletions

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@ -32,6 +32,7 @@ import (
"github.com/calmh/incontainer"
"github.com/julienschmidt/httprouter"
"github.com/prometheus/client_golang/prometheus/promhttp"
"github.com/rcrowley/go-metrics"
"github.com/thejerf/suture/v4"
"github.com/vitrun/qart/qr"
@ -351,6 +352,15 @@ func (s *service) Serve(ctx context.Context) error {
// Handle the special meta.js path
mux.HandleFunc("/meta.js", s.getJSMetadata)
// Handle Prometheus metrics
promHttpHandler := promhttp.Handler()
mux.HandleFunc("/metrics", func(w http.ResponseWriter, req *http.Request) {
// fetching metrics counts as an event, for the purpose of whether
// we should prepare folder summaries etc.
s.fss.OnEventRequest()
promHttpHandler.ServeHTTP(w, req)
})
guiCfg := s.cfg.GUI()
// Wrap everything in CSRF protection. The /rest prefix should be
@ -1214,6 +1224,12 @@ func (s *service) getSupportBundle(w http.ResponseWriter, r *http.Request) {
}
}
// Metrics data as text
buf := bytes.NewBuffer(nil)
wr := bufferedResponseWriter{Writer: buf}
promhttp.Handler().ServeHTTP(wr, &http.Request{Method: http.MethodGet})
files = append(files, fileEntry{name: "metrics.txt", data: buf.Bytes()})
// Heap and CPU Proofs as a pprof extension
var heapBuffer, cpuBuffer bytes.Buffer
filename := fmt.Sprintf("syncthing-heap-%s-%s-%s-%s.pprof", runtime.GOOS, runtime.GOARCH, build.Version, time.Now().Format("150405")) // hhmmss
@ -2043,3 +2059,12 @@ func httpError(w http.ResponseWriter, err error) {
http.Error(w, err.Error(), http.StatusInternalServerError)
}
}
type bufferedResponseWriter struct {
io.Writer
}
func (w bufferedResponseWriter) WriteHeader(int) {}
func (w bufferedResponseWriter) Header() http.Header {
return http.Header{}
}

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@ -297,6 +297,7 @@ loop:
case e := <-l.events:
// Incoming events get sent
l.sendEvent(e)
metricEvents.WithLabelValues(e.Type.String(), metricEventStateCreated).Inc()
case fn := <-l.funcs:
// Subscriptions are handled here.
@ -345,9 +346,11 @@ func (l *logger) sendEvent(e Event) {
select {
case s.events <- e:
metricEvents.WithLabelValues(e.Type.String(), metricEventStateDelivered).Inc()
case <-l.timeout.C:
// if s.events is not ready, drop the event
timedOut = true
metricEvents.WithLabelValues(e.Type.String(), metricEventStateDropped).Inc()
}
// If stop returns false it already sent something to the

25
lib/events/metrics.go Normal file
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@ -0,0 +1,25 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package events
import (
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var metricEvents = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "events",
Name: "total",
Help: "Total number of created/forwarded/dropped events",
}, []string{"event", "state"})
const (
metricEventStateCreated = "created"
metricEventStateDelivered = "delivered"
metricEventStateDropped = "dropped"
)

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@ -28,6 +28,7 @@ const (
filesystemWrapperTypeError
filesystemWrapperTypeWalk
filesystemWrapperTypeLog
filesystemWrapperTypeMetrics
)
type XattrFilter interface {
@ -275,6 +276,8 @@ func NewFilesystem(fsType FilesystemType, uri string, opts ...Option) Filesystem
fs = mtimeOpt.apply(fs)
}
fs = &metricsFS{next: fs}
if l.ShouldDebug("walkfs") {
return NewWalkFilesystem(&logFilesystem{fs})
}

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@ -320,7 +320,15 @@ func TestCopyRange(tttt *testing.T) {
t.Fatal(err)
}
if err := impl(src.(basicFile), dst.(basicFile), testCase.srcOffset, testCase.dstOffset, testCase.copySize); err != nil {
srcBasic, ok := unwrap(src).(basicFile)
if !ok {
t.Fatal("src file is not a basic file")
}
dstBasic, ok := unwrap(dst).(basicFile)
if !ok {
t.Fatal("dst file is not a basic file")
}
if err := impl(srcBasic, dstBasic, testCase.srcOffset, testCase.dstOffset, testCase.copySize); err != nil {
if err == syscall.ENOTSUP {
// Test runner can adjust directory in which to run the tests, that allow broader tests.
t.Skip("Not supported on the current filesystem, set STFSTESTPATH env var.")

339
lib/fs/metrics.go Normal file
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@ -0,0 +1,339 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package fs
import (
"context"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
"github.com/syncthing/syncthing/lib/protocol"
)
var (
metricTotalOperationSeconds = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "fs",
Name: "operation_seconds_total",
Help: "Total time spent in filesystem operations, per filesystem root and operation",
}, []string{"root", "operation"})
metricTotalOperationsCount = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "fs",
Name: "operations_total",
Help: "Total number of filesystem operations, per filesystem root and operation",
}, []string{"root", "operation"})
metricTotalBytesCount = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "fs",
Name: "operation_bytes_total",
Help: "Total number of filesystem bytes transferred, per filesystem root and operation",
}, []string{"root", "operation"})
)
const (
// fs operations
metricOpChmod = "chmod"
metricOpLchmod = "lchmod"
metricOpChtimes = "chtimes"
metricOpCreate = "create"
metricOpCreateSymlink = "createsymlink"
metricOpDirNames = "dirnames"
metricOpLstat = "lstat"
metricOpMkdir = "mdkir"
metricOpMkdirAll = "mkdirall"
metricOpOpen = "open"
metricOpOpenFile = "openfile"
metricOpReadSymlink = "readsymlink"
metricOpRemove = "remove"
metricOpRemoveAll = "removeall"
metricOpRename = "rename"
metricOpStat = "stat"
metricOpSymlinksSupported = "symlinkssupported"
metricOpWalk = "walk"
metricOpWatch = "watch"
metricOpHide = "hide"
metricOpUnhide = "unhide"
metricOpGlob = "glob"
metricOpRoots = "roots"
metricOpUsage = "usage"
metricOpType = "type"
metricOpURI = "uri"
metricOpOptions = "options"
metricOpSameFile = "samefile"
metricOpPlatformData = "platformdata"
metricOpGetXattr = "getxattr"
metricOpSetXattr = "setxattr"
// file operations
metricOpRead = "read"
metricOpReadAt = "readat"
metricOpWrite = "write"
metricOpWriteAt = "writeat"
metricOpTruncate = "truncate"
metricOpSeek = "seek"
metricOpSync = "sync"
metricOpClose = "close"
metricOpName = "name"
)
type metricsFS struct {
next Filesystem
}
var _ Filesystem = (*metricsFS)(nil)
func (m *metricsFS) account(op string) func(bytes int) {
t0 := time.Now()
root := m.next.URI()
return func(bytes int) {
metricTotalOperationSeconds.WithLabelValues(root, op).Add(time.Since(t0).Seconds())
metricTotalOperationsCount.WithLabelValues(root, op).Inc()
if bytes >= 0 {
metricTotalBytesCount.WithLabelValues(root, op).Add(float64(bytes))
}
}
}
func (m *metricsFS) Chmod(name string, mode FileMode) error {
defer m.account(metricOpChmod)(-1)
return m.next.Chmod(name, mode)
}
func (m *metricsFS) Lchown(name string, uid, gid string) error {
defer m.account(metricOpLchmod)(-1)
return m.next.Lchown(name, uid, gid)
}
func (m *metricsFS) Chtimes(name string, atime time.Time, mtime time.Time) error {
defer m.account(metricOpChtimes)(-1)
return m.next.Chtimes(name, atime, mtime)
}
func (m *metricsFS) Create(name string) (File, error) {
defer m.account(metricOpCreate)(-1)
f, err := m.next.Create(name)
if err != nil {
return nil, err
}
return &metricsFile{next: f, fs: m}, nil
}
func (m *metricsFS) CreateSymlink(target, name string) error {
defer m.account(metricOpCreateSymlink)(-1)
return m.next.CreateSymlink(target, name)
}
func (m *metricsFS) DirNames(name string) ([]string, error) {
defer m.account(metricOpDirNames)(-1)
return m.next.DirNames(name)
}
func (m *metricsFS) Lstat(name string) (FileInfo, error) {
defer m.account(metricOpLstat)(-1)
return m.next.Lstat(name)
}
func (m *metricsFS) Mkdir(name string, perm FileMode) error {
defer m.account(metricOpMkdir)(-1)
return m.next.Mkdir(name, perm)
}
func (m *metricsFS) MkdirAll(name string, perm FileMode) error {
defer m.account(metricOpMkdirAll)(-1)
return m.next.MkdirAll(name, perm)
}
func (m *metricsFS) Open(name string) (File, error) {
defer m.account(metricOpOpen)(-1)
f, err := m.next.Open(name)
if err != nil {
return nil, err
}
return &metricsFile{next: f, fs: m}, nil
}
func (m *metricsFS) OpenFile(name string, flags int, mode FileMode) (File, error) {
defer m.account(metricOpOpenFile)(-1)
f, err := m.next.OpenFile(name, flags, mode)
if err != nil {
return nil, err
}
return &metricsFile{next: f, fs: m}, nil
}
func (m *metricsFS) ReadSymlink(name string) (string, error) {
defer m.account(metricOpReadSymlink)(-1)
return m.next.ReadSymlink(name)
}
func (m *metricsFS) Remove(name string) error {
defer m.account(metricOpRemove)(-1)
return m.next.Remove(name)
}
func (m *metricsFS) RemoveAll(name string) error {
defer m.account(metricOpRemoveAll)(-1)
return m.next.RemoveAll(name)
}
func (m *metricsFS) Rename(oldname, newname string) error {
defer m.account(metricOpRename)(-1)
return m.next.Rename(oldname, newname)
}
func (m *metricsFS) Stat(name string) (FileInfo, error) {
defer m.account(metricOpStat)(-1)
return m.next.Stat(name)
}
func (m *metricsFS) SymlinksSupported() bool {
defer m.account(metricOpSymlinksSupported)(-1)
return m.next.SymlinksSupported()
}
func (m *metricsFS) Walk(name string, walkFn WalkFunc) error {
defer m.account(metricOpWalk)(-1)
return m.next.Walk(name, walkFn)
}
func (m *metricsFS) Watch(path string, ignore Matcher, ctx context.Context, ignorePerms bool) (<-chan Event, <-chan error, error) {
defer m.account(metricOpWatch)(-1)
return m.next.Watch(path, ignore, ctx, ignorePerms)
}
func (m *metricsFS) Hide(name string) error {
defer m.account(metricOpHide)(-1)
return m.next.Hide(name)
}
func (m *metricsFS) Unhide(name string) error {
defer m.account(metricOpUnhide)(-1)
return m.next.Unhide(name)
}
func (m *metricsFS) Glob(pattern string) ([]string, error) {
defer m.account(metricOpGlob)(-1)
return m.next.Glob(pattern)
}
func (m *metricsFS) Roots() ([]string, error) {
defer m.account(metricOpRoots)(-1)
return m.next.Roots()
}
func (m *metricsFS) Usage(name string) (Usage, error) {
defer m.account(metricOpUsage)(-1)
return m.next.Usage(name)
}
func (m *metricsFS) Type() FilesystemType {
defer m.account(metricOpType)(-1)
return m.next.Type()
}
func (m *metricsFS) URI() string {
defer m.account(metricOpURI)(-1)
return m.next.URI()
}
func (m *metricsFS) Options() []Option {
defer m.account(metricOpOptions)(-1)
return m.next.Options()
}
func (m *metricsFS) SameFile(fi1, fi2 FileInfo) bool {
defer m.account(metricOpSameFile)(-1)
return m.next.SameFile(fi1, fi2)
}
func (m *metricsFS) PlatformData(name string, withOwnership, withXattrs bool, xattrFilter XattrFilter) (protocol.PlatformData, error) {
defer m.account(metricOpPlatformData)(-1)
return m.next.PlatformData(name, withOwnership, withXattrs, xattrFilter)
}
func (m *metricsFS) GetXattr(name string, xattrFilter XattrFilter) ([]protocol.Xattr, error) {
defer m.account(metricOpGetXattr)(-1)
return m.next.GetXattr(name, xattrFilter)
}
func (m *metricsFS) SetXattr(path string, xattrs []protocol.Xattr, xattrFilter XattrFilter) error {
defer m.account(metricOpSetXattr)(-1)
return m.next.SetXattr(path, xattrs, xattrFilter)
}
func (m *metricsFS) underlying() (Filesystem, bool) {
return m.next, true
}
func (m *metricsFS) wrapperType() filesystemWrapperType {
return filesystemWrapperTypeMetrics
}
type metricsFile struct {
fs *metricsFS
next File
}
func (m *metricsFile) Read(p []byte) (n int, err error) {
acc := m.fs.account(metricOpRead)
defer func() { acc(n) }()
return m.next.Read(p)
}
func (m *metricsFile) ReadAt(p []byte, off int64) (n int, err error) {
acc := m.fs.account(metricOpReadAt)
defer func() { acc(n) }()
return m.next.ReadAt(p, off)
}
func (m *metricsFile) Seek(offset int64, whence int) (int64, error) {
defer m.fs.account(metricOpSeek)(-1)
return m.next.Seek(offset, whence)
}
func (m *metricsFile) Stat() (FileInfo, error) {
defer m.fs.account(metricOpStat)(-1)
return m.next.Stat()
}
func (m *metricsFile) Sync() error {
defer m.fs.account(metricOpSync)(-1)
return m.next.Sync()
}
func (m *metricsFile) Truncate(size int64) error {
defer m.fs.account(metricOpTruncate)(-1)
return m.next.Truncate(size)
}
func (m *metricsFile) Write(p []byte) (n int, err error) {
acc := m.fs.account(metricOpWrite)
defer func() { acc(n) }()
return m.next.Write(p)
}
func (m *metricsFile) WriteAt(p []byte, off int64) (n int, err error) {
acc := m.fs.account(metricOpWriteAt)
defer func() { acc(n) }()
return m.next.WriteAt(p, off)
}
func (m *metricsFile) Close() error {
defer m.fs.account(metricOpClose)(-1)
return m.next.Close()
}
func (m *metricsFile) Name() string {
defer m.fs.account(metricOpName)(-1)
return m.next.Name()
}
func (m *metricsFile) unwrap() File {
return m.next
}

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@ -260,6 +260,8 @@ func newMtimeFS(path string, db database, options ...MtimeFSOption) *mtimeFS {
}
func newMtimeFSWithWalk(path string, db database, options ...MtimeFSOption) (*mtimeFS, *walkFilesystem) {
wfs := NewFilesystem(FilesystemTypeBasic, path, NewMtimeOption(db, options...)).(*walkFilesystem)
return wfs.Filesystem.(*mtimeFS), wfs
fs := NewFilesystem(FilesystemTypeBasic, path, NewMtimeOption(db, options...))
wfs, _ := unwrapFilesystem(fs, filesystemWrapperTypeWalk)
mfs, _ := unwrapFilesystem(fs, filesystemWrapperTypeMtime)
return mfs.(*mtimeFS), wfs.(*walkFilesystem)
}

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@ -137,6 +137,9 @@ func newFolder(model *model, fset *db.FileSet, ignores *ignore.Matcher, cfg conf
f.pullPause = f.pullBasePause()
f.pullFailTimer = time.NewTimer(0)
<-f.pullFailTimer.C
registerFolderMetrics(f.ID)
return f
}
@ -459,6 +462,11 @@ func (f *folder) scanSubdirs(subDirs []string) error {
}
defer f.ioLimiter.Give(1)
metricFolderScans.WithLabelValues(f.ID).Inc()
ctx, cancel := context.WithCancel(f.ctx)
defer cancel()
go addTimeUntilCancelled(ctx, metricFolderScanSeconds.WithLabelValues(f.ID))
for i := range subDirs {
sub := osutil.NativeFilename(subDirs[i])

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@ -8,6 +8,7 @@ package model
import (
"bytes"
"context"
"errors"
"fmt"
"io"
@ -162,11 +163,12 @@ func (f *sendReceiveFolder) pull() (bool, error) {
scanChan := make(chan string)
go f.pullScannerRoutine(scanChan)
defer close(scanChan)
defer func() {
close(scanChan)
f.setState(FolderIdle)
}()
metricFolderPulls.WithLabelValues(f.ID).Inc()
ctx, cancel := context.WithCancel(f.ctx)
defer cancel()
go addTimeUntilCancelled(ctx, metricFolderPullSeconds.WithLabelValues(f.ID))
changed := 0
@ -573,9 +575,9 @@ func (f *sendReceiveFolder) handleDir(file protocol.FileInfo, snap *db.Snapshot,
})
}()
mode := fs.FileMode(file.Permissions & 0777)
mode := fs.FileMode(file.Permissions & 0o777)
if f.IgnorePerms || file.NoPermissions {
mode = 0777
mode = 0o777
}
if shouldDebug() {
@ -705,7 +707,7 @@ func (f *sendReceiveFolder) checkParent(file string, scanChan chan<- string) boo
return true
}
l.Debugf("%v creating parent directory of %v", f, file)
if err := f.mtimefs.MkdirAll(parent, 0755); err != nil {
if err := f.mtimefs.MkdirAll(parent, 0o755); err != nil {
f.newPullError(file, fmt.Errorf("creating parent dir: %w", err))
return false
}
@ -1136,12 +1138,12 @@ func (f *sendReceiveFolder) handleFile(file protocol.FileInfo, snap *db.Snapshot
func (f *sendReceiveFolder) reuseBlocks(blocks []protocol.BlockInfo, reused []int, file protocol.FileInfo, tempName string) ([]protocol.BlockInfo, []int) {
// Check for an old temporary file which might have some blocks we could
// reuse.
tempBlocks, err := scanner.HashFile(f.ctx, f.mtimefs, tempName, file.BlockSize(), nil, false)
tempBlocks, err := scanner.HashFile(f.ctx, f.ID, f.mtimefs, tempName, file.BlockSize(), nil, false)
if err != nil {
var caseErr *fs.ErrCaseConflict
if errors.As(err, &caseErr) {
if rerr := f.mtimefs.Rename(caseErr.Real, tempName); rerr == nil {
tempBlocks, err = scanner.HashFile(f.ctx, f.mtimefs, tempName, file.BlockSize(), nil, false)
tempBlocks, err = scanner.HashFile(f.ctx, f.ID, f.mtimefs, tempName, file.BlockSize(), nil, false)
}
}
}
@ -1235,7 +1237,7 @@ func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan ch
f.queue.Done(file.Name)
if !f.IgnorePerms && !file.NoPermissions {
if err = f.mtimefs.Chmod(file.Name, fs.FileMode(file.Permissions&0777)); err != nil {
if err = f.mtimefs.Chmod(file.Name, fs.FileMode(file.Permissions&0o777)); err != nil {
f.newPullError(file.Name, fmt.Errorf("shortcut file (setting permissions): %w", err))
return
}
@ -1249,7 +1251,7 @@ func (f *sendReceiveFolder) shortcutFile(file protocol.FileInfo, dbUpdateChan ch
// Still need to re-write the trailer with the new encrypted fileinfo.
if f.Type == config.FolderTypeReceiveEncrypted {
err = inWritableDir(func(path string) error {
fd, err := f.mtimefs.OpenFile(path, fs.OptReadWrite, 0666)
fd, err := f.mtimefs.OpenFile(path, fs.OptReadWrite, 0o666)
if err != nil {
return err
}
@ -1329,7 +1331,7 @@ func (f *sendReceiveFolder) copierRoutine(in <-chan copyBlocksState, pullChan ch
// block of all zeroes, so then we should not skip it.
// Pretend we copied it.
state.copiedFromOrigin()
state.skippedSparseBlock(block.Size)
state.copyDone(block)
continue
}
@ -1348,9 +1350,9 @@ func (f *sendReceiveFolder) copierRoutine(in <-chan copyBlocksState, pullChan ch
state.fail(fmt.Errorf("dst write: %w", err))
}
if offset == block.Offset {
state.copiedFromOrigin()
state.copiedFromOrigin(block.Size)
} else {
state.copiedFromOriginShifted()
state.copiedFromOriginShifted(block.Size)
}
return false
@ -1398,7 +1400,9 @@ func (f *sendReceiveFolder) copierRoutine(in <-chan copyBlocksState, pullChan ch
state.fail(fmt.Errorf("dst write: %w", err))
}
if path == state.file.Name {
state.copiedFromOrigin()
state.copiedFromOrigin(block.Size)
} else {
state.copiedFromElsewhere(block.Size)
}
return true
})
@ -1608,7 +1612,7 @@ loop:
func (f *sendReceiveFolder) performFinish(file, curFile protocol.FileInfo, hasCurFile bool, tempName string, snap *db.Snapshot, dbUpdateChan chan<- dbUpdateJob, scanChan chan<- string) error {
// Set the correct permission bits on the new file
if !f.IgnorePerms && !file.NoPermissions {
if err := f.mtimefs.Chmod(tempName, fs.FileMode(file.Permissions&0777)); err != nil {
if err := f.mtimefs.Chmod(tempName, fs.FileMode(file.Permissions&0o777)); err != nil {
return fmt.Errorf("setting permissions: %w", err)
}
}

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@ -299,7 +299,7 @@ func TestCopierFinder(t *testing.T) {
}
// Verify that the fetched blocks have actually been written to the temp file
blks, err := scanner.HashFile(context.TODO(), f.Filesystem(nil), tempFile, protocol.MinBlockSize, nil, false)
blks, err := scanner.HashFile(context.TODO(), f.ID, f.Filesystem(nil), tempFile, protocol.MinBlockSize, nil, false)
if err != nil {
t.Log(err)
}

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@ -396,6 +396,24 @@ func (c *folderSummaryService) sendSummary(ctx context.Context, folder string) {
Summary: data,
})
metricFolderSummary.WithLabelValues(folder, metricScopeGlobal, metricTypeFiles).Set(float64(data.GlobalFiles))
metricFolderSummary.WithLabelValues(folder, metricScopeGlobal, metricTypeDirectories).Set(float64(data.GlobalDirectories))
metricFolderSummary.WithLabelValues(folder, metricScopeGlobal, metricTypeSymlinks).Set(float64(data.GlobalSymlinks))
metricFolderSummary.WithLabelValues(folder, metricScopeGlobal, metricTypeDeleted).Set(float64(data.GlobalDeleted))
metricFolderSummary.WithLabelValues(folder, metricScopeGlobal, metricTypeBytes).Set(float64(data.GlobalBytes))
metricFolderSummary.WithLabelValues(folder, metricScopeLocal, metricTypeFiles).Set(float64(data.LocalFiles))
metricFolderSummary.WithLabelValues(folder, metricScopeLocal, metricTypeDirectories).Set(float64(data.LocalDirectories))
metricFolderSummary.WithLabelValues(folder, metricScopeLocal, metricTypeSymlinks).Set(float64(data.LocalSymlinks))
metricFolderSummary.WithLabelValues(folder, metricScopeLocal, metricTypeDeleted).Set(float64(data.LocalDeleted))
metricFolderSummary.WithLabelValues(folder, metricScopeLocal, metricTypeBytes).Set(float64(data.LocalBytes))
metricFolderSummary.WithLabelValues(folder, metricScopeNeed, metricTypeFiles).Set(float64(data.NeedFiles))
metricFolderSummary.WithLabelValues(folder, metricScopeNeed, metricTypeDirectories).Set(float64(data.NeedDirectories))
metricFolderSummary.WithLabelValues(folder, metricScopeNeed, metricTypeSymlinks).Set(float64(data.NeedSymlinks))
metricFolderSummary.WithLabelValues(folder, metricScopeNeed, metricTypeDeleted).Set(float64(data.NeedDeletes))
metricFolderSummary.WithLabelValues(folder, metricScopeNeed, metricTypeBytes).Set(float64(data.NeedBytes))
for _, devCfg := range c.cfg.Folders()[folder].Devices {
select {
case <-ctx.Done():

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@ -111,6 +111,10 @@ func (s *stateTracker) setState(newState folderState) {
return
}
defer func() {
metricFolderState.WithLabelValues(s.folderID).Set(float64(s.current))
}()
/* This should hold later...
if s.current != FolderIdle && (newState == FolderScanning || newState == FolderSyncing) {
panic("illegal state transition " + s.current.String() + " -> " + newState.String())
@ -148,6 +152,10 @@ func (s *stateTracker) setError(err error) {
s.mut.Lock()
defer s.mut.Unlock()
defer func() {
metricFolderState.WithLabelValues(s.folderID).Set(float64(s.current))
}()
eventData := map[string]interface{}{
"folder": s.folderID,
"from": s.current.String(),

93
lib/model/metrics.go Normal file
View File

@ -0,0 +1,93 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package model
import (
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var (
metricFolderState = promauto.NewGaugeVec(prometheus.GaugeOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_state",
Help: "Current folder state",
}, []string{"folder"})
metricFolderSummary = promauto.NewGaugeVec(prometheus.GaugeOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_summary",
Help: "Current folder summary data (counts for global/local/need files/directories/symlinks/deleted/bytes)",
}, []string{"folder", "scope", "type"})
metricFolderPulls = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_pulls_total",
Help: "Total number of folder pull iterations, per folder ID",
}, []string{"folder"})
metricFolderPullSeconds = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_pull_seconds_total",
Help: "Total time spent in folder pull iterations, per folder ID",
}, []string{"folder"})
metricFolderScans = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_scans_total",
Help: "Total number of folder scan iterations, per folder ID",
}, []string{"folder"})
metricFolderScanSeconds = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_scan_seconds_total",
Help: "Total time spent in folder scan iterations, per folder ID",
}, []string{"folder"})
metricFolderProcessedBytesTotal = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "model",
Name: "folder_processed_bytes_total",
Help: "Total amount of data processed during folder syncing, per folder ID and data source (network/local_origin/local_other/local_shifted/skipped)",
}, []string{"folder", "source"})
)
const (
metricSourceNetwork = "network" // from the network
metricSourceLocalOrigin = "local_origin" // from the existing version of the local file
metricSourceLocalOther = "local_other" // from a different local file
metricSourceLocalShifted = "local_shifted" // from the existing version of the local file, rolling hash shifted
metricSourceSkipped = "skipped" // block of all zeroes, invented out of thin air
metricScopeGlobal = "global"
metricScopeLocal = "local"
metricScopeNeed = "need"
metricTypeFiles = "files"
metricTypeDirectories = "directories"
metricTypeSymlinks = "symlinks"
metricTypeDeleted = "deleted"
metricTypeBytes = "bytes"
)
func registerFolderMetrics(folderID string) {
// Register metrics for this folder, so that counters are present even
// when zero.
metricFolderState.WithLabelValues(folderID)
metricFolderPulls.WithLabelValues(folderID)
metricFolderPullSeconds.WithLabelValues(folderID)
metricFolderScans.WithLabelValues(folderID)
metricFolderScanSeconds.WithLabelValues(folderID)
metricFolderProcessedBytesTotal.WithLabelValues(folderID, metricSourceNetwork)
metricFolderProcessedBytesTotal.WithLabelValues(folderID, metricSourceLocalOrigin)
metricFolderProcessedBytesTotal.WithLabelValues(folderID, metricSourceLocalOther)
metricFolderProcessedBytesTotal.WithLabelValues(folderID, metricSourceLocalShifted)
metricFolderProcessedBytesTotal.WithLabelValues(folderID, metricSourceSkipped)
}

View File

@ -91,7 +91,7 @@ func TestProgressEmitter(t *testing.T) {
expectEvent(w, t, 1)
expectTimeout(w, t)
s.copiedFromOrigin()
s.copiedFromOrigin(1)
expectEvent(w, t, 1)
expectTimeout(w, t)

View File

@ -152,11 +152,11 @@ func (s *sharedPullerState) tempFileInWritableDir(_ string) error {
// permissions will be set to the final value later, but in the meantime
// we don't want to have a temporary file with looser permissions than
// the final outcome.
mode := fs.FileMode(s.file.Permissions) | 0600
mode := fs.FileMode(s.file.Permissions) | 0o600
if s.ignorePerms {
// When ignorePerms is set we use a very permissive mode and let the
// system umask filter it.
mode = 0666
mode = 0o666
}
// Attempt to create the temp file
@ -261,19 +261,34 @@ func (s *sharedPullerState) copyDone(block protocol.BlockInfo) {
s.mut.Unlock()
}
func (s *sharedPullerState) copiedFromOrigin() {
func (s *sharedPullerState) copiedFromOrigin(bytes int) {
s.mut.Lock()
s.copyOrigin++
s.updated = time.Now()
s.mut.Unlock()
metricFolderProcessedBytesTotal.WithLabelValues(s.folder, metricSourceLocalOrigin).Add(float64(bytes))
}
func (s *sharedPullerState) copiedFromOriginShifted() {
func (s *sharedPullerState) copiedFromElsewhere(bytes int) {
metricFolderProcessedBytesTotal.WithLabelValues(s.folder, metricSourceLocalOther).Add(float64(bytes))
}
func (s *sharedPullerState) skippedSparseBlock(bytes int) {
// pretend we copied it, historical
s.mut.Lock()
s.copyOrigin++
s.updated = time.Now()
s.mut.Unlock()
metricFolderProcessedBytesTotal.WithLabelValues(s.folder, metricSourceSkipped).Add(float64(bytes))
}
func (s *sharedPullerState) copiedFromOriginShifted(bytes int) {
s.mut.Lock()
s.copyOrigin++
s.copyOriginShifted++
s.updated = time.Now()
s.mut.Unlock()
metricFolderProcessedBytesTotal.WithLabelValues(s.folder, metricSourceLocalShifted).Add(float64(bytes))
}
func (s *sharedPullerState) pullStarted() {
@ -295,6 +310,7 @@ func (s *sharedPullerState) pullDone(block protocol.BlockInfo) {
s.availableUpdated = time.Now()
l.Debugln("sharedPullerState", s.folder, s.file.Name, "pullNeeded done ->", s.pullNeeded)
s.mut.Unlock()
metricFolderProcessedBytesTotal.WithLabelValues(s.folder, metricSourceNetwork).Add(float64(block.Size))
}
// finalClose atomically closes and returns closed status of a file. A true

View File

@ -7,6 +7,7 @@
package model
import (
"context"
"errors"
"fmt"
"path/filepath"
@ -14,6 +15,7 @@ import (
"sync"
"time"
"github.com/prometheus/client_golang/prometheus"
"github.com/syncthing/syncthing/lib/events"
"github.com/syncthing/syncthing/lib/fs"
"github.com/syncthing/syncthing/lib/ur"
@ -117,11 +119,11 @@ func inWritableDir(fn func(string) error, targetFs fs.Filesystem, path string, i
const permBits = fs.ModePerm | fs.ModeSetuid | fs.ModeSetgid | fs.ModeSticky
var parentErr error
if mode := info.Mode() & permBits; mode&0200 == 0 {
if mode := info.Mode() & permBits; mode&0o200 == 0 {
// A non-writeable directory (for this user; we assume that's the
// relevant part). Temporarily change the mode so we can delete the
// file or directory inside it.
parentErr = targetFs.Chmod(dir, mode|0700)
parentErr = targetFs.Chmod(dir, mode|0o700)
if parentErr != nil {
l.Debugf("Failed to make parent directory writable: %v", parentErr)
} else {
@ -148,3 +150,27 @@ func inWritableDir(fn func(string) error, targetFs fs.Filesystem, path string, i
}
return err
}
// addTimeUntilCancelled adds time to the counter for the duration of the
// Context. We do this piecemeal so that polling the counter during a long
// operation shows a relevant value, instead of the counter just increasing
// by a large amount at the end of the operation.
func addTimeUntilCancelled(ctx context.Context, counter prometheus.Counter) {
t0 := time.Now()
defer func() {
counter.Add(time.Since(t0).Seconds())
}()
ticker := time.NewTicker(time.Second)
defer ticker.Stop()
for {
select {
case t := <-ticker.C:
counter.Add(t.Sub(t0).Seconds())
t0 = t
case <-ctx.Done():
return
}
}
}

View File

@ -10,6 +10,7 @@ import (
type countingReader struct {
io.Reader
idString string
tot atomic.Int64 // bytes
last atomic.Int64 // unix nanos
}
@ -24,6 +25,7 @@ func (c *countingReader) Read(bs []byte) (int, error) {
c.tot.Add(int64(n))
totalIncoming.Add(int64(n))
c.last.Store(time.Now().UnixNano())
metricDeviceRecvBytes.WithLabelValues(c.idString).Add(float64(n))
return n, err
}
@ -35,6 +37,7 @@ func (c *countingReader) Last() time.Time {
type countingWriter struct {
io.Writer
idString string
tot atomic.Int64 // bytes
last atomic.Int64 // unix nanos
}
@ -44,6 +47,7 @@ func (c *countingWriter) Write(bs []byte) (int, error) {
c.tot.Add(int64(n))
totalOutgoing.Add(int64(n))
c.last.Store(time.Now().UnixNano())
metricDeviceSentBytes.WithLabelValues(c.idString).Add(float64(n))
return n, err
}

62
lib/protocol/metrics.go Normal file
View File

@ -0,0 +1,62 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package protocol
import (
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var (
metricDeviceSentBytes = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "sent_bytes_total",
Help: "Total amount of data sent, per device",
}, []string{"device"})
metricDeviceSentUncompressedBytes = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "sent_uncompressed_bytes_total",
Help: "Total amount of data sent, before compression, per device",
}, []string{"device"})
metricDeviceSentMessages = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "sent_messages_total",
Help: "Total number of messages sent, per device",
}, []string{"device"})
metricDeviceRecvBytes = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "recv_bytes_total",
Help: "Total amount of data received, per device",
}, []string{"device"})
metricDeviceRecvDecompressedBytes = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "recv_decompressed_bytes_total",
Help: "Total amount of data received, after decompression, per device",
}, []string{"device"})
metricDeviceRecvMessages = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "protocol",
Name: "recv_messages_total",
Help: "Total number of messages received, per device",
}, []string{"device"})
)
func registerDeviceMetrics(deviceID string) {
// Register metrics for this device, so that counters are present even
// when zero.
metricDeviceSentBytes.WithLabelValues(deviceID)
metricDeviceSentUncompressedBytes.WithLabelValues(deviceID)
metricDeviceSentMessages.WithLabelValues(deviceID)
metricDeviceRecvBytes.WithLabelValues(deviceID)
metricDeviceRecvMessages.WithLabelValues(deviceID)
}

View File

@ -183,6 +183,7 @@ type rawConnection struct {
ConnectionInfo
deviceID DeviceID
idString string
model contextLessModel
startTime time.Time
@ -263,12 +264,15 @@ func NewConnection(deviceID DeviceID, reader io.Reader, writer io.Writer, closer
}
func newRawConnection(deviceID DeviceID, reader io.Reader, writer io.Writer, closer io.Closer, receiver contextLessModel, connInfo ConnectionInfo, compress Compression) *rawConnection {
cr := &countingReader{Reader: reader}
cw := &countingWriter{Writer: writer}
idString := deviceID.String()
cr := &countingReader{Reader: reader, idString: idString}
cw := &countingWriter{Writer: writer, idString: idString}
registerDeviceMetrics(idString)
return &rawConnection{
ConnectionInfo: connInfo,
deviceID: deviceID,
idString: deviceID.String(),
model: receiver,
cr: cr,
cw: cw,
@ -445,6 +449,8 @@ func (c *rawConnection) dispatcherLoop() (err error) {
return ErrClosed
}
metricDeviceRecvMessages.WithLabelValues(c.idString).Inc()
msgContext, err := messageContext(msg)
if err != nil {
return fmt.Errorf("protocol error: %w", err)
@ -553,6 +559,8 @@ func (c *rawConnection) readMessageAfterHeader(hdr Header, fourByteBuf []byte) (
// ... and is then unmarshalled
metricDeviceRecvDecompressedBytes.WithLabelValues(c.idString).Add(float64(4 + len(buf)))
msg, err := newMessage(hdr.Type)
if err != nil {
BufferPool.Put(buf)
@ -593,6 +601,8 @@ func (c *rawConnection) readHeader(fourByteBuf []byte) (Header, error) {
return Header{}, fmt.Errorf("unmarshalling header: %w", err)
}
metricDeviceRecvDecompressedBytes.WithLabelValues(c.idString).Add(float64(2 + len(buf)))
return hdr, nil
}
@ -758,6 +768,10 @@ func (c *rawConnection) writeMessage(msg message) error {
msgContext, _ := messageContext(msg)
l.Debugf("Writing %v", msgContext)
defer func() {
metricDeviceSentMessages.WithLabelValues(c.idString).Inc()
}()
size := msg.ProtoSize()
hdr := Header{
Type: typeOf(msg),
@ -784,6 +798,8 @@ func (c *rawConnection) writeMessage(msg message) error {
}
}
metricDeviceSentUncompressedBytes.WithLabelValues(c.idString).Add(float64(totSize))
// Header length
binary.BigEndian.PutUint16(buf, uint16(hdrSize))
// Header
@ -817,6 +833,9 @@ func (c *rawConnection) writeCompressedMessage(msg message, marshaled []byte) (o
}
cOverhead := 2 + hdrSize + 4
metricDeviceSentUncompressedBytes.WithLabelValues(c.idString).Add(float64(cOverhead + len(marshaled)))
// The compressed size may be at most n-n/32 = .96875*n bytes,
// I.e., if we can't save at least 3.125% bandwidth, we forgo compression.
// This number is arbitrary but cheap to compute.

View File

@ -16,7 +16,7 @@ import (
)
// HashFile hashes the files and returns a list of blocks representing the file.
func HashFile(ctx context.Context, fs fs.Filesystem, path string, blockSize int, counter Counter, useWeakHashes bool) ([]protocol.BlockInfo, error) {
func HashFile(ctx context.Context, folderID string, fs fs.Filesystem, path string, blockSize int, counter Counter, useWeakHashes bool) ([]protocol.BlockInfo, error) {
fd, err := fs.Open(path)
if err != nil {
l.Debugln("open:", err)
@ -42,6 +42,8 @@ func HashFile(ctx context.Context, fs fs.Filesystem, path string, blockSize int,
return nil, err
}
metricHashedBytes.WithLabelValues(folderID).Add(float64(size))
// Recheck the size and modtime again. If they differ, the file changed
// while we were reading it and our hash results are invalid.
@ -62,6 +64,7 @@ func HashFile(ctx context.Context, fs fs.Filesystem, path string, blockSize int,
// workers are used in parallel. The outbox will become closed when the inbox
// is closed and all items handled.
type parallelHasher struct {
folderID string
fs fs.Filesystem
outbox chan<- ScanResult
inbox <-chan protocol.FileInfo
@ -70,8 +73,9 @@ type parallelHasher struct {
wg sync.WaitGroup
}
func newParallelHasher(ctx context.Context, fs fs.Filesystem, workers int, outbox chan<- ScanResult, inbox <-chan protocol.FileInfo, counter Counter, done chan<- struct{}) {
func newParallelHasher(ctx context.Context, folderID string, fs fs.Filesystem, workers int, outbox chan<- ScanResult, inbox <-chan protocol.FileInfo, counter Counter, done chan<- struct{}) {
ph := &parallelHasher{
folderID: folderID,
fs: fs,
outbox: outbox,
inbox: inbox,
@ -104,7 +108,7 @@ func (ph *parallelHasher) hashFiles(ctx context.Context) {
panic("Bug. Asked to hash a directory or a deleted file.")
}
blocks, err := HashFile(ctx, ph.fs, f.Name, f.BlockSize(), ph.counter, true)
blocks, err := HashFile(ctx, ph.folderID, ph.fs, f.Name, f.BlockSize(), ph.counter, true)
if err != nil {
handleError(ctx, "hashing", f.Name, err, ph.outbox)
continue

35
lib/scanner/metrics.go Normal file
View File

@ -0,0 +1,35 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
package scanner
import (
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/promauto"
)
var (
metricHashedBytes = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "scanner",
Name: "hashed_bytes_total",
Help: "Total amount of data hashed, per folder",
}, []string{"folder"})
metricScannedItems = promauto.NewCounterVec(prometheus.CounterOpts{
Namespace: "syncthing",
Subsystem: "scanner",
Name: "scanned_items_total",
Help: "Total number of items (files/directories) inspected, per folder",
}, []string{"folder"})
)
func registerFolderMetrics(folderID string) {
// Register metrics for this folder, so that counters are present even
// when zero.
metricHashedBytes.WithLabelValues(folderID)
metricScannedItems.WithLabelValues(folderID)
}

View File

@ -115,7 +115,7 @@ type fakeInfo struct {
}
func (f fakeInfo) Name() string { return f.name }
func (fakeInfo) Mode() fs.FileMode { return 0755 }
func (fakeInfo) Mode() fs.FileMode { return 0o755 }
func (f fakeInfo) Size() int64 { return f.size }
func (fakeInfo) ModTime() time.Time { return time.Unix(1234567890, 0) }
func (f fakeInfo) IsDir() bool {

View File

@ -104,6 +104,7 @@ func newWalker(cfg Config) *walker {
w.Matcher = ignore.New(w.Filesystem)
}
registerFolderMetrics(w.Folder)
return w
}
@ -132,7 +133,7 @@ func (w *walker) walk(ctx context.Context) chan ScanResult {
// We're not required to emit scan progress events, just kick off hashers,
// and feed inputs directly from the walker.
if w.ProgressTickIntervalS < 0 {
newParallelHasher(ctx, w.Filesystem, w.Hashers, finishedChan, toHashChan, nil, nil)
newParallelHasher(ctx, w.Folder, w.Filesystem, w.Hashers, finishedChan, toHashChan, nil, nil)
return finishedChan
}
@ -163,7 +164,7 @@ func (w *walker) walk(ctx context.Context) chan ScanResult {
done := make(chan struct{})
progress := newByteCounter()
newParallelHasher(ctx, w.Filesystem, w.Hashers, finishedChan, realToHashChan, progress, done)
newParallelHasher(ctx, w.Folder, w.Filesystem, w.Hashers, finishedChan, realToHashChan, progress, done)
// A routine which actually emits the FolderScanProgress events
// every w.ProgressTicker ticks, until the hasher routines terminate.
@ -255,6 +256,8 @@ func (w *walker) walkAndHashFiles(ctx context.Context, toHashChan chan<- protoco
default:
}
metricScannedItems.WithLabelValues(w.Folder).Inc()
// Return value used when we are returning early and don't want to
// process the item. For directories, this means do-not-descend.
var skip error // nil
@ -599,7 +602,7 @@ func (w *walker) updateFileInfo(dst, src protocol.FileInfo) protocol.FileInfo {
if dst.Type == protocol.FileInfoTypeFile && build.IsWindows {
// If we have an existing index entry, copy the executable bits
// from there.
dst.Permissions |= (src.Permissions & 0111)
dst.Permissions |= (src.Permissions & 0o111)
}
dst.Version = src.Version.Update(w.ShortID)
dst.ModifiedBy = w.ShortID

View File

@ -635,7 +635,7 @@ func BenchmarkHashFile(b *testing.B) {
b.ResetTimer()
for i := 0; i < b.N; i++ {
if _, err := HashFile(context.TODO(), testFs, testdataName, protocol.MinBlockSize, nil, true); err != nil {
if _, err := HashFile(context.TODO(), "", testFs, testdataName, protocol.MinBlockSize, nil, true); err != nil {
b.Fatal(err)
}
}

187
script/find-metrics.go Normal file
View File

@ -0,0 +1,187 @@
// Copyright (C) 2023 The Syncthing Authors.
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this file,
// You can obtain one at https://mozilla.org/MPL/2.0/.
// Usage: go run script/find-metrics.go > metrics.md
//
// This script finds all of the metrics in the Syncthing codebase and prints
// them in Markdown format. It's used to generate the metrics documentation
// for the Syncthing docs.
package main
import (
"fmt"
"go/ast"
"go/token"
"log"
"strconv"
"strings"
"golang.org/x/exp/slices"
"golang.org/x/tools/go/packages"
)
type metric struct {
subsystem string
name string
help string
kind string
}
func main() {
opts := &packages.Config{
Mode: packages.NeedSyntax | packages.NeedName | packages.NeedTypes | packages.NeedTypesInfo | packages.NeedImports | packages.NeedDeps,
}
pkgs, err := packages.Load(opts, "github.com/syncthing/syncthing/...")
if err != nil {
log.Fatalln(err)
}
var coll metricCollector
for _, pkg := range pkgs {
for _, file := range pkg.Syntax {
ast.Inspect(file, coll.Visit)
}
}
coll.print()
}
type metricCollector struct {
metrics []metric
}
func (c *metricCollector) Visit(n ast.Node) bool {
if gen, ok := n.(*ast.GenDecl); ok {
// We're only interested in var declarations (var metricWhatever =
// promauto.NewCounter(...) etc).
if gen.Tok != token.VAR {
return false
}
for _, spec := range gen.Specs {
// We want to look at the value given to a var (the NewCounter()
// etc call).
if vsp, ok := spec.(*ast.ValueSpec); ok {
// There should be only one value.
if len(vsp.Values) != 1 {
continue
}
// The value should be a function call.
call, ok := vsp.Values[0].(*ast.CallExpr)
if !ok {
continue
}
// The call should be a selector expression
// (package.Identifer).
sel, ok := call.Fun.(*ast.SelectorExpr)
if !ok {
continue
}
// The package selector should be `promauto`.
selID, ok := sel.X.(*ast.Ident)
if !ok || selID.Name != "promauto" {
continue
}
// The function should be one of the New* functions.
var kind string
switch sel.Sel.Name {
case "NewCounter":
kind = "counter"
case "NewGauge":
kind = "gauge"
case "NewCounterVec":
kind = "counter vector"
case "NewGaugeVec":
kind = "gauge vector"
default:
continue
}
// The arguments to the function should be a single
// composite (struct literal). Grab all of the fields in the
// declaration into a map so we can easily access them.
args := make(map[string]string)
for _, el := range call.Args[0].(*ast.CompositeLit).Elts {
kv := el.(*ast.KeyValueExpr)
key := kv.Key.(*ast.Ident).Name // e.g., "Name"
val := kv.Value.(*ast.BasicLit).Value // e.g., `"foo"`
args[key], _ = strconv.Unquote(val)
}
// Build the full name of the metric from the namespace +
// subsystem + name, like Prometheus does.
var parts []string
if v := args["Namespace"]; v != "" {
parts = append(parts, v)
}
if v := args["Subsystem"]; v != "" {
parts = append(parts, v)
}
if v := args["Name"]; v != "" {
parts = append(parts, v)
}
fullName := strings.Join(parts, "_")
// Add the metric to the list.
c.metrics = append(c.metrics, metric{
subsystem: args["Subsystem"],
name: fullName,
help: args["Help"],
kind: kind,
})
}
}
}
return true
}
func (c *metricCollector) print() {
slices.SortFunc(c.metrics, func(a, b metric) bool {
if a.subsystem != b.subsystem {
return a.subsystem < b.subsystem
}
return a.name < b.name
})
var prevSubsystem string
for _, m := range c.metrics {
if m.subsystem != prevSubsystem {
fmt.Printf("## Package `%s`\n\n", m.subsystem)
prevSubsystem = m.subsystem
}
fmt.Printf("### `%v` (%s)\n\n%s\n\n", m.name, m.kind, wordwrap(sentenceize(m.help), 72))
}
}
func sentenceize(s string) string {
if s == "" {
return ""
}
if !strings.HasSuffix(s, ".") {
return s + "."
}
return s
}
func wordwrap(s string, width int) string {
var lines []string
for _, line := range strings.Split(s, "\n") {
for len(line) > width {
i := strings.LastIndex(line[:width], " ")
if i == -1 {
i = width
}
lines = append(lines, line[:i])
line = line[i+1:]
}
lines = append(lines, line)
}
return strings.Join(lines, "\n")
}