metrics, pprof: support reloading services with SIGHUP

Reload prometheus and pprof services, even if the config is not updated.

Closes #1868.

Signed-off-by: Andrey Butusov <andrey@nspcc.io>

CHANGELOG.md

@@ -19,6 +19,7 @@ attribute, which is used for container domain name in NNS contracts (#2954)
 - Docs files for cli commands to the `docs/cli-commands` folder (#2983)
 - `logger.encoding` config option (#2999)
 - Reloading morph endpoints with SIGHUP (#2998)
+- Reloading pprof/metrics services with SIGHUP (#3016)
 
 ### Fixed
 - Do not search for tombstones when handling their expiration, use local indexes instead (#2929)

cmd/neofs-node/config.go

@@ -9,6 +9,7 @@ import (
 	"os"
 	"os/signal"
 	"path/filepath"
+	"slices"
 	"sync"
 	"sync/atomic"
 	"syscall"
@@ -848,6 +849,18 @@ func (c *cfg) configWatcher(ctx context.Context) {
 				continue
 			}
 
+			// Prometheus and pprof
+
+			for _, lastCloser := range c.veryLastClosers {
+				lastCloser()
+			}
+
+			c.veryLastClosers = slices.Delete(c.veryLastClosers, 0, len(c.veryLastClosers))
+
+			preRunAndLog(c, "prometheus", initMetrics(c))
+
+			preRunAndLog(c, "pprof", initProfiler(c))
+
 			// Logger
 
 			err = c.internals.logLevel.UnmarshalText([]byte(c.logger.level))