[#125] ir: Reconfigure pprof and metrics on SIGHUP

Signed-off-by: Anton Nikiforov <an.nikiforov@yadro.com>

cmd/frostfs-ir/httpcomponent.go

@@ -0,0 +1,80 @@
+package main
+
+import (
+	"fmt"
+	"net/http"
+	"time"
+
+	"git.frostfs.info/TrueCloudLab/frostfs-node/internal/logs"
+	httputil "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/http"
+	"go.uber.org/zap"
+)
+
+type httpComponent struct {
+	srv                *httputil.Server
+	address            string
+	addressKey         string
+	name               string
+	handler            http.Handler
+	shutdownDur        time.Duration
+	shutdownTimeoutKey string
+	enabled            bool
+	enabledKey         string
+}
+
+func (c *httpComponent) init() {
+	log.Info(fmt.Sprintf("init %s", c.name))
+	c.enabled = cfg.GetBool(c.enabledKey)
+	c.address = cfg.GetString(c.addressKey)
+	c.shutdownDur = cfg.GetDuration(c.shutdownTimeoutKey)
+
+	if c.enabled {
+		c.srv = httputil.New(
+			httputil.HTTPSrvPrm{
+				Address: c.address,
+				Handler: c.handler,
+			},
+			httputil.WithShutdownTimeout(c.shutdownDur),
+		)
+	} else {
+		log.Info(fmt.Sprintf("%s is disabled, skip", c.name))
+		c.srv = nil
+	}
+}
+
+func (c *httpComponent) start() {
+	if c.srv != nil {
+		log.Info(fmt.Sprintf("start %s", c.name))
+		wg.Add(1)
+		go func() {
+			exitErr(c.srv.Serve())
+			wg.Done()
+		}()
+	}
+}
+
+func (c *httpComponent) shutdown() error {
+	if c.srv != nil {
+		log.Info(fmt.Sprintf("shutdown %s", c.name))
+		return c.srv.Shutdown()
+	}
+	return nil
+}
+
+func (c *httpComponent) reload() {
+	log.Info(fmt.Sprintf("reload %s", c.name))
+	enabled := cfg.GetBool(c.enabledKey)
+	address := cfg.GetString(c.addressKey)
+	dur := cfg.GetDuration(c.shutdownTimeoutKey)
+	if enabled != c.enabled || address != c.address || dur != c.shutdownDur {
+		log.Info(fmt.Sprintf("%s config updated", c.name))
+		if err := c.shutdown(); err != nil {
+			log.Debug(logs.FrostFSIRCouldNotShutdownHTTPServer,
+				zap.String("error", err.Error()),
+			)
+		} else {
+			c.init()
+			c.start()
+		}
+	}
+}