Files
cgrates/agents/prometheus.go
ionutboangiu e79fcdb064 use pre-defined instrumented prometheus handler
instead of creating the handler on each scrape
2025-03-09 17:27:31 +01:00

124 lines
3.9 KiB
Go

/*
Real-time Online/Offline Charging System (OCS) for Telecom & ISP environments
Copyright (C) ITsysCOM GmbH
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
*/
package agents
import (
"fmt"
"net/http"
"github.com/cgrates/birpc/context"
"github.com/cgrates/cgrates/config"
"github.com/cgrates/cgrates/engine"
"github.com/cgrates/cgrates/utils"
"github.com/prometheus/client_golang/prometheus"
"github.com/prometheus/client_golang/prometheus/collectors"
"github.com/prometheus/client_golang/prometheus/promhttp"
)
// PrometheusAgent handles metrics collection for Prometheus.
// It collects stats from StatQueues and exposes them alongside
// optional Go runtime and process metrics.
type PrometheusAgent struct {
cfg *config.CGRConfig
filters *engine.FilterS
cm *engine.ConnManager
shutdown *utils.SyncedChan
handler http.Handler
reg *prometheus.Registry
statMetrics *prometheus.GaugeVec
}
// NewPrometheusAgent creates and initializes a PrometheusAgent with
// pre-registered metrics based on the provided configuration.
func NewPrometheusAgent(cfg *config.CGRConfig, filters *engine.FilterS, cm *engine.ConnManager,
shutdown *utils.SyncedChan) *PrometheusAgent {
reg := prometheus.NewRegistry()
statMetrics := prometheus.NewGaugeVec(
prometheus.GaugeOpts{
Namespace: "cgrates",
Subsystem: "stats",
Name: "metrics",
Help: "Current values for StatQueue metrics",
}, []string{"tenant", "queue", "metric"})
reg.MustRegister(statMetrics)
if cfg.PrometheusAgentCfg().CollectGoMetrics {
reg.MustRegister(collectors.NewGoCollector())
}
if cfg.PrometheusAgentCfg().CollectProcessMetrics {
reg.MustRegister(collectors.NewProcessCollector(collectors.ProcessCollectorOpts{}))
}
handler := promhttp.InstrumentMetricHandler(
reg,
promhttp.HandlerFor(reg, promhttp.HandlerOpts{}),
)
return &PrometheusAgent{
cfg: cfg,
filters: filters,
cm: cm,
shutdown: shutdown,
handler: handler,
reg: reg,
statMetrics: statMetrics,
}
}
// updateStatsMetrics fetches and updates all StatQueue metrics by calling each
// configured StatS connection.
func (pa *PrometheusAgent) updateStatsMetrics() {
if len(pa.cfg.PrometheusAgentCfg().StatQueueIDs) == 0 {
return
}
for _, connID := range pa.cfg.PrometheusAgentCfg().StatSConns {
for _, sqID := range pa.cfg.PrometheusAgentCfg().StatQueueIDs {
tenantID := utils.NewTenantID(sqID)
if tenantID.Tenant == "" {
tenantID.Tenant = pa.cfg.GeneralCfg().DefaultTenant
}
var metrics map[string]float64
err := pa.cm.Call(context.Background(), []string{connID},
utils.StatSv1GetQueueFloatMetrics,
&utils.TenantIDWithAPIOpts{
TenantID: tenantID,
}, &metrics)
if err != nil && err.Error() != utils.ErrNotFound.Error() {
utils.Logger.Err(fmt.Sprintf(
"<%s> failed to retrieve metrics for StatQueue %q (connID=%q): %v",
utils.PrometheusAgent, sqID, connID, err))
continue
}
for metricID, val := range metrics {
pa.statMetrics.WithLabelValues(tenantID.Tenant, tenantID.ID, metricID).Set(val)
}
}
}
}
// ServeHTTP implements http.Handler interface. It updates all metrics on each
// scrape request before exposing them via the Prometheus HTTP handler.
func (pa *PrometheusAgent) ServeHTTP(w http.ResponseWriter, r *http.Request) {
pa.updateStatsMetrics()
pa.handler.ServeHTTP(w, r)
}