feat(env): auto set GOMAXPROCS by go.uber.org/automaxprocs (#6576)

---------

Signed-off-by: dongjiang1989 <dongjiang1989@126.com>

cmd/operator/main.go

@@ -24,6 +24,7 @@ import (
 	"os"
 	"os/signal"
 	"regexp"
+	"strings"
 	"syscall"
 
 	"github.com/go-kit/log"
@@ -33,6 +34,7 @@ import (
 	versioncollector "github.com/prometheus/client_golang/prometheus/collectors/version"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"github.com/prometheus/common/version"
+	"go.uber.org/automaxprocs/maxprocs"
 	"golang.org/x/sync/errgroup"
 	corev1 "k8s.io/api/core/v1"
 	storagev1 "k8s.io/api/storage/v1"
@@ -184,6 +186,13 @@ func run(fs *flag.FlagSet) int {
 		stdlog.Fatal(err)
 	}
 
+	l := func(format string, a ...interface{}) {
+		level.Info(logger).Log("component", "automaxprocs", "msg", fmt.Sprintf(strings.TrimPrefix(format, "maxprocs: "), a...))
+	}
+	if _, err := maxprocs.Set(maxprocs.Logger(l)); err != nil {
+		level.Warn(logger).Log("msg", "Failed to set GOMAXPROCS automatically", "err", err)
+	}
+
 	level.Info(logger).Log("msg", "Starting Prometheus Operator", "version", version.Info())
 	level.Info(logger).Log("build_context", version.BuildContext())
 

cmd/prometheus-config-reloader/main.go

@@ -37,6 +37,7 @@ import (
 	"github.com/prometheus/common/version"
 	"github.com/prometheus/exporter-toolkit/web"
 	"github.com/thanos-io/thanos/pkg/reloader"
+	"go.uber.org/automaxprocs/maxprocs"
 
 	logging "github.com/prometheus-operator/prometheus-operator/internal/log"
 	"github.com/prometheus-operator/prometheus-operator/pkg/operator"
@@ -122,6 +123,13 @@ func main() {
 		stdlog.Fatal(err)
 	}
 
+	l := func(format string, a ...interface{}) {
+		level.Info(logger).Log("component", "automaxprocs", "msg", fmt.Sprintf(strings.TrimPrefix(format, "maxprocs: "), a...))
+	}
+	if _, err := maxprocs.Set(maxprocs.Logger(l)); err != nil {
+		level.Warn(logger).Log("msg", "Failed to set GOMAXPROCS automatically", "err", err)
+	}
+
 	err = web.Validate(*webConfig)
 	if err != nil {
 		level.Error(logger).Log("msg", "Unable to validate web configuration file", "err", err)