[#552] Add sdnotify package

To avoid using third-party dependencies.

Signed-off-by: Ekaterina Lebedeva <ekaterina.lebedeva@yadro.com>

cmd/frostfs-node/control.go

@@ -10,8 +10,8 @@ import (
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control"
 	controlSvc "git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/control/server"
 	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/services/tree"
+	"git.frostfs.info/TrueCloudLab/frostfs-node/pkg/util/sdnotify"
 	cid "git.frostfs.info/TrueCloudLab/frostfs-sdk-go/container/id"
-	sysdnotify "github.com/iguanesolutions/go-systemd/v5/notify"
 	"go.uber.org/zap"
 	"google.golang.org/grpc"
 )
@@ -109,14 +109,13 @@ func (c *cfg) HealthStatus() control.HealthStatus {
 	return control.HealthStatus(c.healthStatus.Load())
 }
 
-func (c *cfg) notifySystemd(st control.HealthStatus) string {
+func (c *cfg) notifySystemd(st control.HealthStatus) {
 	status := fmt.Sprintf("%v, %v", st.Number(), st)
-	err := sysdnotify.Status(status)
+	err := sdnotify.Status(status)
 	if err == nil {
 		c.log.Info(fmt.Sprintf("reported STATUS=\"%v\" to systemd", status))
 	}
 	if err != nil {
 		c.log.Error(logs.FailedToReportStatusToSystemd, zap.String("error", err.Error()))
 	}
-	return fmt.Sprintf("%v, %v", st, control.HealthStatus_name[int32(st)])
 }

go.mod

@@ -16,7 +16,6 @@ require (
 	github.com/flynn-archive/go-shlex v0.0.0-20150515145356-3f9db97f8568
 	github.com/google/uuid v1.4.0
 	github.com/hashicorp/golang-lru/v2 v2.0.7
-	github.com/iguanesolutions/go-systemd/v5 v5.1.1
 	github.com/klauspost/compress v1.17.4
 	github.com/mitchellh/go-homedir v1.1.0
 	github.com/mr-tron/base58 v1.2.0

go.sum

@@ -146,18 +146,6 @@ github.com/holiman/uint256 v1.2.4 h1:jUc4Nk8fm9jZabQuqr2JzednajVmBpC+oiTiXZJEApU
 github.com/holiman/uint256 v1.2.4/go.mod h1:EOMSn4q6Nyt9P6efbI3bueV4e1b3dGlUCXeiRV4ng7E=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=
-github.com/ianlancetaylor/demangle v0.0.0-20230524184225-eabc099b10ab/go.mod h1:gx7rwoVhcfuVKG5uya9Hs3Sxj7EIvldVofAWIUtGouw=
-github.com/iguanesolutions/go-systemd/v5 v5.1.1 h1:Hs0Z16knPGCBFnKECrICPh+RQ89Sgy0xyzcalrHMKdw=
-github.com/iguanesolutions/go-systemd/v5 v5.1.1/go.mod h1:Quv57scs6S7T0rC6qyLfW20KU/P4p9hrbLPF+ILYrXY=
-github.com/imdario/mergo v0.3.5/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
-github.com/imdario/mergo v0.3.6/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
-github.com/imdario/mergo v0.3.8/go.mod h1:2EnlNZ0deacrJVfApfmtdGgDfMuh/nq6Ok1EcJh5FfA=
-github.com/imdario/mergo v0.3.10/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
-github.com/imdario/mergo v0.3.11/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
-github.com/imdario/mergo v0.3.12/go.mod h1:jmQim1M+e3UYxmgPu/WyfjB3N3VflVyUjjjwH0dnCYA=
-github.com/imdario/mergo v0.3.13/go.mod h1:4lJ1jqUDcsbIECGy0RUJAXNIhg+6ocWgb1ALK2O4oXg=
-github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
-github.com/inconshreveable/mousetrap v1.0.1/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/ipfs/go-cid v0.4.1 h1:A/T3qGvxi4kpKWWcPC/PgbvDA2bjVLO7n4UeVwnbs/s=

pkg/util/sdnotify/sdnotify.go

@@ -0,0 +1,59 @@
+package sdnotify
+
+import (
+	"fmt"
+	"net"
+	"os"
+	"strings"
+)
+
+const (
+	ReadyEnabled     = "READY=1"
+	StoppingEnabled  = "STOPPING=1"
+	ReloadingEnabled = "RELOADING=1"
+)
+
+var socket *net.UnixAddr
+
+// Initializes socket with provided name of
+// environment variable.
+func InitSocket() error {
+	notifySocket := os.Getenv("NOTIFY_SOCKET")
+	if notifySocket == "" {
+		return fmt.Errorf("\"NOTIFY_SOCKET\" environment variable is not present")
+	}
+	socket = &net.UnixAddr{
+		Name: notifySocket,
+		Net:  "unixgram",
+	}
+	return nil
+}
+
+// FlagAndStatus sends systemd a combination of a
+// well-known status and STATUS=%s{status}, separated by newline.
+func FlagAndStatus(status string) error {
+	status += "\nSTATUS=" + strings.TrimSuffix(status, "=1")
+	return Send(status)
+}
+
+// Status sends systemd notify STATUS=%s{status}.
+func Status(status string) error {
+	return Send(fmt.Sprintf("STATUS=%s", status))
+}
+
+// Send state through the notify socket if any.
+// If the notify socket was not detected, it returns an error.
+func Send(state string) error {
+	if socket == nil {
+		return fmt.Errorf("socket is not initialized")
+	}
+	conn, err := net.DialUnix(socket.Net, nil, socket)
+	if err != nil {
+		return fmt.Errorf("can't open unix socket: %v", err)
+	}
+	defer conn.Close()
+	if _, err = conn.Write([]byte(state)); err != nil {
+		return fmt.Errorf("can't write into the unix socket: %v", err)
+	}
+	return nil
+}