50 lines
1.3 KiB
Go
50 lines
1.3 KiB
Go
package agent
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import (
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"net/http"
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"sync"
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"github.com/prometheus/client_golang/prometheus"
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"github.com/prometheus/client_golang/prometheus/promhttp"
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)
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var (
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// Only create the prometheus handler once
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promHandler http.Handler
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promOnce sync.Once
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)
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// MetricsRequest returns metrics for the agent. Metrics are JSON by default
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// but Prometheus is an optional format.
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func (s *HTTPServer) MetricsRequest(resp http.ResponseWriter, req *http.Request) (interface{}, error) {
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if req.Method != "GET" {
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return nil, CodedError(405, ErrInvalidMethod)
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}
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if format := req.URL.Query().Get("format"); format == "prometheus" {
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// Only return Prometheus formatted metrics if the user has enabled
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// this functionality.
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if !s.agent.config.Telemetry.PrometheusMetrics {
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return nil, CodedError(http.StatusUnsupportedMediaType, "Prometheus is not enabled")
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}
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s.prometheusHandler().ServeHTTP(resp, req)
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return nil, nil
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}
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return s.agent.InmemSink.DisplayMetrics(resp, req)
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}
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func (s *HTTPServer) prometheusHandler() http.Handler {
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promOnce.Do(func() {
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handlerOptions := promhttp.HandlerOpts{
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ErrorLog: s.logger.Named("prometheus_handler").StandardLogger(nil),
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ErrorHandling: promhttp.ContinueOnError,
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DisableCompression: true,
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}
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promHandler = promhttp.HandlerFor(prometheus.DefaultGatherer, handlerOptions)
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})
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return promHandler
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}
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