caddy-log-exporter/vendor/github.com/VictoriaMetrics/metrics/push.go
2024-09-19 11:21:05 +02:00

511 lines
18 KiB
Go

package metrics
import (
"bytes"
"context"
"errors"
"fmt"
"io"
"io/ioutil"
"log"
"net/http"
"net/url"
"strings"
"sync"
"time"
"compress/gzip"
)
// PushOptions is the list of options, which may be applied to InitPushWithOptions().
type PushOptions struct {
// ExtraLabels is an optional comma-separated list of `label="value"` labels, which must be added to all the metrics before pushing them to pushURL.
ExtraLabels string
// Headers is an optional list of HTTP headers to add to every push request to pushURL.
//
// Every item in the list must have the form `Header: value`. For example, `Authorization: Custom my-top-secret`.
Headers []string
// Whether to disable HTTP request body compression before sending the metrics to pushURL.
//
// By default the compression is enabled.
DisableCompression bool
// Method is HTTP request method to use when pushing metrics to pushURL.
//
// By default the Method is GET.
Method string
// Optional WaitGroup for waiting until all the push workers created with this WaitGroup are stopped.
WaitGroup *sync.WaitGroup
}
// InitPushWithOptions sets up periodic push for globally registered metrics to the given pushURL with the given interval.
//
// The periodic push is stopped when ctx is canceled.
// It is possible to wait until the background metrics push worker is stopped on a WaitGroup passed via opts.WaitGroup.
//
// If pushProcessMetrics is set to true, then 'process_*' and `go_*` metrics are also pushed to pushURL.
//
// opts may contain additional configuration options if non-nil.
//
// The metrics are pushed to pushURL in Prometheus text exposition format.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPushWithOptions multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
func InitPushWithOptions(ctx context.Context, pushURL string, interval time.Duration, pushProcessMetrics bool, opts *PushOptions) error {
writeMetrics := func(w io.Writer) {
WritePrometheus(w, pushProcessMetrics)
}
return InitPushExtWithOptions(ctx, pushURL, interval, writeMetrics, opts)
}
// InitPushProcessMetrics sets up periodic push for 'process_*' metrics to the given pushURL with the given interval.
//
// extraLabels may contain comma-separated list of `label="value"` labels, which will be added
// to all the metrics before pushing them to pushURL.
//
// The metrics are pushed to pushURL in Prometheus text exposition format.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPushProcessMetrics multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
func InitPushProcessMetrics(pushURL string, interval time.Duration, extraLabels string) error {
return InitPushExt(pushURL, interval, extraLabels, WriteProcessMetrics)
}
// InitPush sets up periodic push for globally registered metrics to the given pushURL with the given interval.
//
// extraLabels may contain comma-separated list of `label="value"` labels, which will be added
// to all the metrics before pushing them to pushURL.
//
// If pushProcessMetrics is set to true, then 'process_*' and `go_*` metrics are also pushed to pushURL.
//
// The metrics are pushed to pushURL in Prometheus text exposition format.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPush multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
func InitPush(pushURL string, interval time.Duration, extraLabels string, pushProcessMetrics bool) error {
writeMetrics := func(w io.Writer) {
WritePrometheus(w, pushProcessMetrics)
}
return InitPushExt(pushURL, interval, extraLabels, writeMetrics)
}
// PushMetrics pushes globally registered metrics to pushURL.
//
// If pushProcessMetrics is set to true, then 'process_*' and `go_*` metrics are also pushed to pushURL.
//
// opts may contain additional configuration options if non-nil.
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
func PushMetrics(ctx context.Context, pushURL string, pushProcessMetrics bool, opts *PushOptions) error {
writeMetrics := func(w io.Writer) {
WritePrometheus(w, pushProcessMetrics)
}
return PushMetricsExt(ctx, pushURL, writeMetrics, opts)
}
// InitPushWithOptions sets up periodic push for metrics from s to the given pushURL with the given interval.
//
// The periodic push is stopped when the ctx is canceled.
// It is possible to wait until the background metrics push worker is stopped on a WaitGroup passed via opts.WaitGroup.
//
// opts may contain additional configuration options if non-nil.
//
// The metrics are pushed to pushURL in Prometheus text exposition format.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPushWithOptions multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
func (s *Set) InitPushWithOptions(ctx context.Context, pushURL string, interval time.Duration, opts *PushOptions) error {
return InitPushExtWithOptions(ctx, pushURL, interval, s.WritePrometheus, opts)
}
// InitPush sets up periodic push for metrics from s to the given pushURL with the given interval.
//
// extraLabels may contain comma-separated list of `label="value"` labels, which will be added
// to all the metrics before pushing them to pushURL.
//
// The metrics are pushed to pushURL in Prometheus text exposition format.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPush multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
func (s *Set) InitPush(pushURL string, interval time.Duration, extraLabels string) error {
return InitPushExt(pushURL, interval, extraLabels, s.WritePrometheus)
}
// PushMetrics pushes s metrics to pushURL.
//
// opts may contain additional configuration options if non-nil.
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
func (s *Set) PushMetrics(ctx context.Context, pushURL string, opts *PushOptions) error {
return PushMetricsExt(ctx, pushURL, s.WritePrometheus, opts)
}
// InitPushExt sets up periodic push for metrics obtained by calling writeMetrics with the given interval.
//
// extraLabels may contain comma-separated list of `label="value"` labels, which will be added
// to all the metrics before pushing them to pushURL.
//
// The writeMetrics callback must write metrics to w in Prometheus text exposition format without timestamps and trailing comments.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPushExt multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
//
// It is OK calling InitPushExt multiple times with different writeMetrics -
// in this case all the metrics generated by writeMetrics callbacks are written to pushURL.
func InitPushExt(pushURL string, interval time.Duration, extraLabels string, writeMetrics func(w io.Writer)) error {
opts := &PushOptions{
ExtraLabels: extraLabels,
}
return InitPushExtWithOptions(context.Background(), pushURL, interval, writeMetrics, opts)
}
// InitPushExtWithOptions sets up periodic push for metrics obtained by calling writeMetrics with the given interval.
//
// The writeMetrics callback must write metrics to w in Prometheus text exposition format without timestamps and trailing comments.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// The periodic push is stopped when the ctx is canceled.
// It is possible to wait until the background metrics push worker is stopped on a WaitGroup passed via opts.WaitGroup.
//
// opts may contain additional configuration options if non-nil.
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
//
// It is OK calling InitPushExtWithOptions multiple times with different pushURL -
// in this case metrics are pushed to all the provided pushURL urls.
//
// It is OK calling InitPushExtWithOptions multiple times with different writeMetrics -
// in this case all the metrics generated by writeMetrics callbacks are written to pushURL.
func InitPushExtWithOptions(ctx context.Context, pushURL string, interval time.Duration, writeMetrics func(w io.Writer), opts *PushOptions) error {
pc, err := newPushContext(pushURL, opts)
if err != nil {
return err
}
// validate interval
if interval <= 0 {
return fmt.Errorf("interval must be positive; got %s", interval)
}
pushMetricsSet.GetOrCreateFloatCounter(fmt.Sprintf(`metrics_push_interval_seconds{url=%q}`, pc.pushURLRedacted)).Set(interval.Seconds())
var wg *sync.WaitGroup
if opts != nil {
wg = opts.WaitGroup
if wg != nil {
wg.Add(1)
}
}
go func() {
ticker := time.NewTicker(interval)
defer ticker.Stop()
stopCh := ctx.Done()
for {
select {
case <-ticker.C:
ctxLocal, cancel := context.WithTimeout(ctx, interval+time.Second)
err := pc.pushMetrics(ctxLocal, writeMetrics)
cancel()
if err != nil {
log.Printf("ERROR: metrics.push: %s", err)
}
case <-stopCh:
if wg != nil {
wg.Done()
}
return
}
}
}()
return nil
}
// PushMetricsExt pushes metrics generated by wirteMetrics to pushURL.
//
// The writeMetrics callback must write metrics to w in Prometheus text exposition format without timestamps and trailing comments.
// See https://github.com/prometheus/docs/blob/main/content/docs/instrumenting/exposition_formats.md#text-based-format
//
// opts may contain additional configuration options if non-nil.
//
// It is recommended pushing metrics to /api/v1/import/prometheus endpoint according to
// https://docs.victoriametrics.com/#how-to-import-data-in-prometheus-exposition-format
func PushMetricsExt(ctx context.Context, pushURL string, writeMetrics func(w io.Writer), opts *PushOptions) error {
pc, err := newPushContext(pushURL, opts)
if err != nil {
return err
}
return pc.pushMetrics(ctx, writeMetrics)
}
type pushContext struct {
pushURL *url.URL
method string
pushURLRedacted string
extraLabels string
headers http.Header
disableCompression bool
client *http.Client
pushesTotal *Counter
bytesPushedTotal *Counter
pushBlockSize *Histogram
pushDuration *Histogram
pushErrors *Counter
}
func newPushContext(pushURL string, opts *PushOptions) (*pushContext, error) {
if opts == nil {
opts = &PushOptions{}
}
// validate pushURL
pu, err := url.Parse(pushURL)
if err != nil {
return nil, fmt.Errorf("cannot parse pushURL=%q: %w", pushURL, err)
}
if pu.Scheme != "http" && pu.Scheme != "https" {
return nil, fmt.Errorf("unsupported scheme in pushURL=%q; expecting 'http' or 'https'", pushURL)
}
if pu.Host == "" {
return nil, fmt.Errorf("missing host in pushURL=%q", pushURL)
}
method := opts.Method
if method == "" {
method = http.MethodGet
}
// validate ExtraLabels
extraLabels := opts.ExtraLabels
if err := validateTags(extraLabels); err != nil {
return nil, fmt.Errorf("invalid extraLabels=%q: %w", extraLabels, err)
}
// validate Headers
headers := make(http.Header)
for _, h := range opts.Headers {
n := strings.IndexByte(h, ':')
if n < 0 {
return nil, fmt.Errorf("missing `:` delimiter in the header %q", h)
}
name := strings.TrimSpace(h[:n])
value := strings.TrimSpace(h[n+1:])
headers.Add(name, value)
}
pushURLRedacted := pu.Redacted()
client := &http.Client{}
return &pushContext{
pushURL: pu,
method: method,
pushURLRedacted: pushURLRedacted,
extraLabels: extraLabels,
headers: headers,
disableCompression: opts.DisableCompression,
client: client,
pushesTotal: pushMetricsSet.GetOrCreateCounter(fmt.Sprintf(`metrics_push_total{url=%q}`, pushURLRedacted)),
bytesPushedTotal: pushMetricsSet.GetOrCreateCounter(fmt.Sprintf(`metrics_push_bytes_pushed_total{url=%q}`, pushURLRedacted)),
pushBlockSize: pushMetricsSet.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_block_size_bytes{url=%q}`, pushURLRedacted)),
pushDuration: pushMetricsSet.GetOrCreateHistogram(fmt.Sprintf(`metrics_push_duration_seconds{url=%q}`, pushURLRedacted)),
pushErrors: pushMetricsSet.GetOrCreateCounter(fmt.Sprintf(`metrics_push_errors_total{url=%q}`, pushURLRedacted)),
}, nil
}
func (pc *pushContext) pushMetrics(ctx context.Context, writeMetrics func(w io.Writer)) error {
bb := getBytesBuffer()
defer putBytesBuffer(bb)
writeMetrics(bb)
if len(pc.extraLabels) > 0 {
bbTmp := getBytesBuffer()
bbTmp.B = append(bbTmp.B[:0], bb.B...)
bb.B = addExtraLabels(bb.B[:0], bbTmp.B, pc.extraLabels)
putBytesBuffer(bbTmp)
}
if !pc.disableCompression {
bbTmp := getBytesBuffer()
bbTmp.B = append(bbTmp.B[:0], bb.B...)
bb.B = bb.B[:0]
zw := getGzipWriter(bb)
if _, err := zw.Write(bbTmp.B); err != nil {
panic(fmt.Errorf("BUG: cannot write %d bytes to gzip writer: %s", len(bbTmp.B), err))
}
if err := zw.Close(); err != nil {
panic(fmt.Errorf("BUG: cannot flush metrics to gzip writer: %s", err))
}
putGzipWriter(zw)
putBytesBuffer(bbTmp)
}
// Update metrics
pc.pushesTotal.Inc()
blockLen := len(bb.B)
pc.bytesPushedTotal.Add(blockLen)
pc.pushBlockSize.Update(float64(blockLen))
// Prepare the request to sent to pc.pushURL
reqBody := bytes.NewReader(bb.B)
req, err := http.NewRequestWithContext(ctx, pc.method, pc.pushURL.String(), reqBody)
if err != nil {
panic(fmt.Errorf("BUG: metrics.push: cannot initialize request for metrics push to %q: %w", pc.pushURLRedacted, err))
}
req.Header.Set("Content-Type", "text/plain")
// Set the needed headers, and `Content-Type` allowed be overwrited.
for name, values := range pc.headers {
for _, value := range values {
req.Header.Add(name, value)
}
}
if !pc.disableCompression {
req.Header.Set("Content-Encoding", "gzip")
}
// Perform the request
startTime := time.Now()
resp, err := pc.client.Do(req)
pc.pushDuration.UpdateDuration(startTime)
if err != nil {
if errors.Is(err, context.Canceled) {
return nil
}
pc.pushErrors.Inc()
return fmt.Errorf("cannot push metrics to %q: %s", pc.pushURLRedacted, err)
}
if resp.StatusCode/100 != 2 {
body, _ := ioutil.ReadAll(resp.Body)
_ = resp.Body.Close()
pc.pushErrors.Inc()
return fmt.Errorf("unexpected status code in response from %q: %d; expecting 2xx; response body: %q", pc.pushURLRedacted, resp.StatusCode, body)
}
_ = resp.Body.Close()
return nil
}
var pushMetricsSet = NewSet()
func writePushMetrics(w io.Writer) {
pushMetricsSet.WritePrometheus(w)
}
func addExtraLabels(dst, src []byte, extraLabels string) []byte {
for len(src) > 0 {
var line []byte
n := bytes.IndexByte(src, '\n')
if n >= 0 {
line = src[:n]
src = src[n+1:]
} else {
line = src
src = nil
}
line = bytes.TrimSpace(line)
if len(line) == 0 {
// Skip empy lines
continue
}
if bytes.HasPrefix(line, bashBytes) {
// Copy comments as is
dst = append(dst, line...)
dst = append(dst, '\n')
continue
}
n = bytes.IndexByte(line, '{')
if n >= 0 {
dst = append(dst, line[:n+1]...)
dst = append(dst, extraLabels...)
dst = append(dst, ',')
dst = append(dst, line[n+1:]...)
} else {
n = bytes.LastIndexByte(line, ' ')
if n < 0 {
panic(fmt.Errorf("BUG: missing whitespace between metric name and metric value in Prometheus text exposition line %q", line))
}
dst = append(dst, line[:n]...)
dst = append(dst, '{')
dst = append(dst, extraLabels...)
dst = append(dst, '}')
dst = append(dst, line[n:]...)
}
dst = append(dst, '\n')
}
return dst
}
var bashBytes = []byte("#")
func getBytesBuffer() *bytesBuffer {
v := bytesBufferPool.Get()
if v == nil {
return &bytesBuffer{}
}
return v.(*bytesBuffer)
}
func putBytesBuffer(bb *bytesBuffer) {
bb.B = bb.B[:0]
bytesBufferPool.Put(bb)
}
var bytesBufferPool sync.Pool
type bytesBuffer struct {
B []byte
}
func (bb *bytesBuffer) Write(p []byte) (int, error) {
bb.B = append(bb.B, p...)
return len(p), nil
}
func getGzipWriter(w io.Writer) *gzip.Writer {
v := gzipWriterPool.Get()
if v == nil {
return gzip.NewWriter(w)
}
zw := v.(*gzip.Writer)
zw.Reset(w)
return zw
}
func putGzipWriter(zw *gzip.Writer) {
zw.Reset(io.Discard)
gzipWriterPool.Put(zw)
}
var gzipWriterPool sync.Pool