Move OpenMetrics options to a separate struct

Signed-off-by: Arthur Silva Sens <arthur.sens@coralogix.com>
This commit is contained in:
Arthur Silva Sens 2024-02-18 15:29:40 -03:00
parent c4e464b60a
commit 65df2d7147
No known key found for this signature in database
5 changed files with 58 additions and 33 deletions

View File

@ -51,8 +51,10 @@ func main() {
"/metrics", promhttp.HandlerFor(
registry,
promhttp.HandlerOpts{
EnableOpenMetrics: true,
EnableOpenMetricsCreatedMetrics: true,
OpenMetricsOptions: promhttp.OpenMetricsOptions{
Enable: true,
EnableCreatedTimestamps: true,
},
}),
)
// To test: curl -H 'Accept: application/openmetrics-text' localhost:8080/metrics

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@ -61,7 +61,9 @@ func main() {
"/metrics", promhttp.HandlerFor(
registry,
promhttp.HandlerOpts{
EnableOpenMetrics: true,
OpenMetricsOptions: promhttp.OpenMetricsOptions{
Enable: true,
},
}),
)
// To test: curl -H 'Accept: application/openmetrics-text' localhost:8080/metrics

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@ -47,8 +47,10 @@ func main() {
http.Handle("/metrics", promhttp.HandlerFor(
reg,
promhttp.HandlerOpts{
// Opt into OpenMetrics to support exemplars.
EnableOpenMetrics: true,
OpenMetricsOptions: promhttp.OpenMetricsOptions{
// Opt into OpenMetrics to support exemplars.
Enable: true,
},
},
))
fmt.Println("Hello world from new Go Collector!")

View File

@ -134,8 +134,10 @@ func main() {
http.Handle("/metrics", promhttp.HandlerFor(
reg,
promhttp.HandlerOpts{
// Opt into OpenMetrics to support exemplars.
EnableOpenMetrics: true,
OpenMetricsOptions: promhttp.OpenMetricsOptions{
// Opt into OpenMetrics to support exemplars.
Enable: true,
},
// Pass custom registry
Registry: reg,
},

View File

@ -160,7 +160,7 @@ func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerO
}
var contentType expfmt.Format
if opts.EnableOpenMetrics {
if opts.EnableOpenMetrics || opts.OpenMetricsOptions.Enable {
contentType = expfmt.NegotiateIncludingOpenMetrics(req.Header)
} else {
contentType = expfmt.Negotiate(req.Header)
@ -181,7 +181,7 @@ func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerO
}
var enc expfmt.Encoder
if opts.EnableOpenMetricsCreatedMetrics {
if opts.OpenMetricsOptions.EnableCreatedTimestamps {
enc = expfmt.NewEncoder(w, contentType, expfmt.WithCreatedLines())
} else {
enc = expfmt.NewEncoder(w, contentType)
@ -366,31 +366,11 @@ type HandlerOpts struct {
// away). Until the implementation is improved, it is recommended to
// implement a separate timeout in potentially slow Collectors.
Timeout time.Duration
// If true, the experimental OpenMetrics encoding is added to the
// possible options during content negotiation. Note that Prometheus
// 2.5.0+ will negotiate OpenMetrics as first priority. OpenMetrics is
// the only way to transmit exemplars. However, the move to OpenMetrics
// is not completely transparent. Most notably, the values of "quantile"
// labels of Summaries and "le" labels of Histograms are formatted with
// a trailing ".0" if they would otherwise look like integer numbers
// (which changes the identity of the resulting series on the Prometheus
// server).
// Deprecated: Use OpenMetricsOptions.Enable instead.
EnableOpenMetrics bool
// If 'EnableOpenMetrics' is true, 'EnableOpenMetricsCreatedMetrics' allows
// to add extra '_created' lines for counters, histograms and summaries,
// as defined in the OpenMetrics specification (see
// https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#counter-1).
// Created timestamps are used to improve the accuracy of reset detection,
// but be aware that it also increases the size of the payload.
//
// Prometheus introduced the feature flag 'created-timestamp-zero-ingestion'
// in version 2.50.0, but with support limited to the Prometheus protobuf
// format. Starting in Prometheus XXXX, the feature flag will be extended
// to the OpenMetrics text format. If using Prometheus XXXX or later, it
// is recommended to enable the feature flag in Prometheus, otherwise enabling
// _created lines will result in increased cardinality and no improvements
// in reset detection.
EnableOpenMetricsCreatedMetrics bool
// OpenMetricsOptions holds settings for the experimental OpenMetrics encoding.
// It can be used to enable OpenMetrics encoding and for setting extra options.
OpenMetricsOptions OpenMetricsOptions
// ProcessStartTime allows setting process start timevalue that will be exposed
// with "Process-Start-Time-Unix" response header along with the metrics
// payload. This allow callers to have efficient transformations to cumulative
@ -401,6 +381,43 @@ type HandlerOpts struct {
ProcessStartTime time.Time
}
type OpenMetricsOptions struct {
// Enable specifies if the experimental OpenMetrics encoding is added to the
// possible options during content negotiation.
//
// Note that Prometheus 2.5.0+ might negotiate OpenMetrics Text format
// as first priority unless user uses custom scrape protocol prioritization or
// histograms feature is enabled (then Prometheus proto format is prioritized,
// which client_golang supports).
//
// Keep in mind that the move to OpenMetrics is not completely transparent. Most notably,
// the values of "quantile" labels of Summaries and "le" labels of Histograms are
// formatted with a trailing ".0" if they would otherwise look like integer numbers
// (which changes the identity of the resulting series on the Prometheus
// server).
//
// See other options in OpenMetricsOptions to learn how to enable some special
// features e.g. potentially dangerous created timestamp series.
Enable bool
// EnableCreatedTimestamps specifies if this handler should add, extra, synthetic
// Created Timestamps for counters, histograms and summaries, which for the current
// version of OpenMetrics are defined as extra series with the same name and "_created"
// suffix. See also the OpenMetrics specification for more details
// https://github.com/OpenObservability/OpenMetrics/blob/main/specification/OpenMetrics.md#counter-1
//
// Created timestamps are used to improve the accuracy of reset detection,
// but the way it's designed in OpenMetrics 1.0 it also dramatically increases cardinality
// if the scraper does not handle those metrics correctly (converting to created timestamp
// instead of leaving those series as-is). New OpenMetrics versions might improve
// this situation.
//
// Prometheus introduced the feature flag 'created-timestamp-zero-ingestion'
// in version 2.50.0, but only for the Prometheus protobuf format. Starting in
// future Prometheus version, the feature flag will be extended to the OpenMetrics
// text format, thus safe to be enabled to improve accuracy of counters in Prometheus.
EnableCreatedTimestamps bool
}
// gzipAccepted returns whether the client will accept gzip-encoded content.
func gzipAccepted(header http.Header) bool {
a := header.Get(acceptEncodingHeader)