WIP: implemented Ping, implemented Set and Shutdown in agent, and added umask

.idea/.gitignore

@@ -0,0 +1,8 @@
+# Default ignored files
+/shelf/
+/workspace.xml
+# Editor-based HTTP Client requests
+/httpRequests/
+# Datasource local storage ignored files
+/dataSources/
+/dataSources.local.xml

.idea/go-agent.iml

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<module type="WEB_MODULE" version="4">
+  <component name="Go" enabled="true" />
+  <component name="NewModuleRootManager">
+    <content url="file://$MODULE_DIR$" />
+    <orderEntry type="inheritedJdk" />
+    <orderEntry type="sourceFolder" forTests="false" />
+  </component>
+</module>

.idea/modules.xml

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="ProjectModuleManager">
+    <modules>
+      <module fileurl="file://$PROJECT_DIR$/.idea/go-agent.iml" filepath="$PROJECT_DIR$/.idea/go-agent.iml" />
+    </modules>
+  </component>
+</project>

.idea/vcs.xml

@@ -0,0 +1,6 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project version="4">
+  <component name="VcsDirectoryMappings">
+    <mapping directory="" vcs="Git" />
+  </component>
+</project>

agent/agent.go

@@ -19,6 +19,7 @@ limitations under the License.
 import (
 	"context"
 	"fmt"
+	"google.golang.org/protobuf/types/known/emptypb"
 	"net"
 
 	pb "gitea.suyono.dev/suyono/go-agent/proto"
@@ -51,6 +52,10 @@ func NewCacheConn(socketPath string) (CacheConn, error) {
 	}
 
 	result.client = pb.NewAgentClient(result.conn)
+	if _, err = result.client.Ping(context.Background(), new(emptypb.Empty)); err != nil {
+		return result, err
+	}
+
 	return result, nil
 }
 
@@ -71,4 +76,26 @@ func (c CacheConn) Get(ctx context.Context, key string) (string, error) {
 	return rpcResult.Value, nil
 }
 
-//TODO: implement Set and Shutdown
+func (c CacheConn) Set(ctx context.Context, key string, value string) error {
+	rpcStatus, err := c.client.Set(ctx, &pb.CacheSetRequest{Key: key, Value: value})
+	if err != nil {
+		return fmt.Errorf("set to cache: %w", err)
+	}
+
+	if rpcStatus.Status != "OK" {
+		return fmt.Errorf("set to cache: status %s with message %s", rpcStatus.Status, rpcStatus.Message)
+	}
+	return nil
+}
+
+func (c CacheConn) Shutdown(ctx context.Context) error {
+	_, err := c.client.Shutdown(ctx, new(emptypb.Empty))
+	if err != nil {
+		return fmt.Errorf("shutdown: %w", err)
+	}
+	return nil
+}
+
+func (c CacheConn) Close() error {
+	return c.conn.Close()
+}

proto/agent.pb.go

@@ -1,8 +1,8 @@
 // Code generated by protoc-gen-go. DO NOT EDIT.
 // versions:
 // 	protoc-gen-go v1.36.6
-// 	protoc        v6.31.1
+// 	protoc        v5.29.3
-// source: gitea.suyono.dev/suyono/go-agent/proto/agent.proto
+// source: agent.proto
 
 package proto
 
@@ -31,7 +31,7 @@ type CacheGetRequest struct {
 
 func (x *CacheGetRequest) Reset() {
 	*x = CacheGetRequest{}
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[0]
+	mi := &file_agent_proto_msgTypes[0]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -43,7 +43,7 @@ func (x *CacheGetRequest) String() string {
 func (*CacheGetRequest) ProtoMessage() {}
 
 func (x *CacheGetRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[0]
+	mi := &file_agent_proto_msgTypes[0]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -56,7 +56,7 @@ func (x *CacheGetRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CacheGetRequest.ProtoReflect.Descriptor instead.
 func (*CacheGetRequest) Descriptor() ([]byte, []int) {
-	return file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescGZIP(), []int{0}
+	return file_agent_proto_rawDescGZIP(), []int{0}
 }
 
 func (x *CacheGetRequest) GetKey() string {
@@ -77,7 +77,7 @@ type CacheValue struct {
 
 func (x *CacheValue) Reset() {
 	*x = CacheValue{}
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[1]
+	mi := &file_agent_proto_msgTypes[1]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -89,7 +89,7 @@ func (x *CacheValue) String() string {
 func (*CacheValue) ProtoMessage() {}
 
 func (x *CacheValue) ProtoReflect() protoreflect.Message {
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[1]
+	mi := &file_agent_proto_msgTypes[1]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -102,7 +102,7 @@ func (x *CacheValue) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CacheValue.ProtoReflect.Descriptor instead.
 func (*CacheValue) Descriptor() ([]byte, []int) {
-	return file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescGZIP(), []int{1}
+	return file_agent_proto_rawDescGZIP(), []int{1}
 }
 
 func (x *CacheValue) GetStatus() string {
@@ -136,7 +136,7 @@ type CacheSetRequest struct {
 
 func (x *CacheSetRequest) Reset() {
 	*x = CacheSetRequest{}
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[2]
+	mi := &file_agent_proto_msgTypes[2]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -148,7 +148,7 @@ func (x *CacheSetRequest) String() string {
 func (*CacheSetRequest) ProtoMessage() {}
 
 func (x *CacheSetRequest) ProtoReflect() protoreflect.Message {
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[2]
+	mi := &file_agent_proto_msgTypes[2]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -161,7 +161,7 @@ func (x *CacheSetRequest) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use CacheSetRequest.ProtoReflect.Descriptor instead.
 func (*CacheSetRequest) Descriptor() ([]byte, []int) {
-	return file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescGZIP(), []int{2}
+	return file_agent_proto_rawDescGZIP(), []int{2}
 }
 
 func (x *CacheSetRequest) GetKey() string {
@@ -188,7 +188,7 @@ type SetStatus struct {
 
 func (x *SetStatus) Reset() {
 	*x = SetStatus{}
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[3]
+	mi := &file_agent_proto_msgTypes[3]
 	ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 	ms.StoreMessageInfo(mi)
 }
@@ -200,7 +200,7 @@ func (x *SetStatus) String() string {
 func (*SetStatus) ProtoMessage() {}
 
 func (x *SetStatus) ProtoReflect() protoreflect.Message {
-	mi := &file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes[3]
+	mi := &file_agent_proto_msgTypes[3]
 	if x != nil {
 		ms := protoimpl.X.MessageStateOf(protoimpl.Pointer(x))
 		if ms.LoadMessageInfo() == nil {
@@ -213,7 +213,7 @@ func (x *SetStatus) ProtoReflect() protoreflect.Message {
 
 // Deprecated: Use SetStatus.ProtoReflect.Descriptor instead.
 func (*SetStatus) Descriptor() ([]byte, []int) {
-	return file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescGZIP(), []int{3}
+	return file_agent_proto_rawDescGZIP(), []int{3}
 }
 
 func (x *SetStatus) GetStatus() string {
@@ -230,11 +230,11 @@ func (x *SetStatus) GetMessage() string {
 	return ""
 }
 
-var File_gitea_suyono_dev_suyono_go_agent_proto_agent_proto protoreflect.FileDescriptor
+var File_agent_proto protoreflect.FileDescriptor
 
-const file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc = "" +
+const file_agent_proto_rawDesc = "" +
 	"\n" +
-	"2gitea.suyono.dev/suyono/go-agent/proto/agent.proto\x12\x05proto\x1a\x1bgoogle/protobuf/empty.proto\"#\n" +
+	"\vagent.proto\x12\x05proto\x1a\x1bgoogle/protobuf/empty.proto\"#\n" +
 	"\x0fCacheGetRequest\x12\x10\n" +
 	"\x03key\x18\x01 \x01(\tR\x03key\"T\n" +
 	"\n" +
@@ -247,66 +247,69 @@ const file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc = "" +
 	"\x05value\x18\x02 \x01(\tR\x05value\"=\n" +
 	"\tSetStatus\x12\x16\n" +
 	"\x06status\x18\x01 \x01(\tR\x06status\x12\x18\n" +
-	"\amessage\x18\x02 \x01(\tR\amessage2\xa6\x01\n" +
+	"\amessage\x18\x02 \x01(\tR\amessage2\xde\x01\n" +
 	"\x05Agent\x120\n" +
 	"\x03Get\x12\x16.proto.CacheGetRequest\x1a\x11.proto.CacheValue\x12/\n" +
 	"\x03Set\x12\x16.proto.CacheSetRequest\x1a\x10.proto.SetStatus\x12:\n" +
-	"\bShutdown\x12\x16.google.protobuf.Empty\x1a\x16.google.protobuf.EmptyB.Z,gitea.suyono.dev/suyono/go-agent/proto;protob\x06proto3"
+	"\bShutdown\x12\x16.google.protobuf.Empty\x1a\x16.google.protobuf.Empty\x126\n" +
+	"\x04Ping\x12\x16.google.protobuf.Empty\x1a\x16.google.protobuf.EmptyB.Z,gitea.suyono.dev/suyono/go-agent/proto;protob\x06proto3"
 
 var (
-	file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescOnce sync.Once
+	file_agent_proto_rawDescOnce sync.Once
-	file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescData []byte
+	file_agent_proto_rawDescData []byte
 )
 
-func file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescGZIP() []byte {
+func file_agent_proto_rawDescGZIP() []byte {
-	file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescOnce.Do(func() {
+	file_agent_proto_rawDescOnce.Do(func() {
-		file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc), len(file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc)))
+		file_agent_proto_rawDescData = protoimpl.X.CompressGZIP(unsafe.Slice(unsafe.StringData(file_agent_proto_rawDesc), len(file_agent_proto_rawDesc)))
 	})
-	return file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDescData
+	return file_agent_proto_rawDescData
 }
 
-var file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes = make([]protoimpl.MessageInfo, 4)
+var file_agent_proto_msgTypes = make([]protoimpl.MessageInfo, 4)
-var file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_goTypes = []any{
+var file_agent_proto_goTypes = []any{
 	(*CacheGetRequest)(nil), // 0: proto.CacheGetRequest
 	(*CacheValue)(nil),      // 1: proto.CacheValue
 	(*CacheSetRequest)(nil), // 2: proto.CacheSetRequest
 	(*SetStatus)(nil),       // 3: proto.SetStatus
 	(*emptypb.Empty)(nil),   // 4: google.protobuf.Empty
 }
-var file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_depIdxs = []int32{
+var file_agent_proto_depIdxs = []int32{
 	0, // 0: proto.Agent.Get:input_type -> proto.CacheGetRequest
 	2, // 1: proto.Agent.Set:input_type -> proto.CacheSetRequest
 	4, // 2: proto.Agent.Shutdown:input_type -> google.protobuf.Empty
-	1, // 3: proto.Agent.Get:output_type -> proto.CacheValue
+	4, // 3: proto.Agent.Ping:input_type -> google.protobuf.Empty
-	3, // 4: proto.Agent.Set:output_type -> proto.SetStatus
+	1, // 4: proto.Agent.Get:output_type -> proto.CacheValue
-	4, // 5: proto.Agent.Shutdown:output_type -> google.protobuf.Empty
+	3, // 5: proto.Agent.Set:output_type -> proto.SetStatus
-	3, // [3:6] is the sub-list for method output_type
+	4, // 6: proto.Agent.Shutdown:output_type -> google.protobuf.Empty
-	0, // [0:3] is the sub-list for method input_type
+	4, // 7: proto.Agent.Ping:output_type -> google.protobuf.Empty
+	4, // [4:8] is the sub-list for method output_type
+	0, // [0:4] is the sub-list for method input_type
 	0, // [0:0] is the sub-list for extension type_name
 	0, // [0:0] is the sub-list for extension extendee
 	0, // [0:0] is the sub-list for field type_name
 }
 
-func init() { file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_init() }
+func init() { file_agent_proto_init() }
-func file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_init() {
+func file_agent_proto_init() {
-	if File_gitea_suyono_dev_suyono_go_agent_proto_agent_proto != nil {
+	if File_agent_proto != nil {
 		return
 	}
 	type x struct{}
 	out := protoimpl.TypeBuilder{
 		File: protoimpl.DescBuilder{
 			GoPackagePath: reflect.TypeOf(x{}).PkgPath(),
-			RawDescriptor: unsafe.Slice(unsafe.StringData(file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc), len(file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_rawDesc)),
+			RawDescriptor: unsafe.Slice(unsafe.StringData(file_agent_proto_rawDesc), len(file_agent_proto_rawDesc)),
 			NumEnums:      0,
 			NumMessages:   4,
 			NumExtensions: 0,
 			NumServices:   1,
 		},
-		GoTypes:           file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_goTypes,
+		GoTypes:           file_agent_proto_goTypes,
-		DependencyIndexes: file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_depIdxs,
+		DependencyIndexes: file_agent_proto_depIdxs,
-		MessageInfos:      file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_msgTypes,
+		MessageInfos:      file_agent_proto_msgTypes,
 	}.Build()
-	File_gitea_suyono_dev_suyono_go_agent_proto_agent_proto = out.File
+	File_agent_proto = out.File
-	file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_goTypes = nil
+	file_agent_proto_goTypes = nil
-	file_gitea_suyono_dev_suyono_go_agent_proto_agent_proto_depIdxs = nil
+	file_agent_proto_depIdxs = nil
 }

proto/agent.proto

@@ -30,5 +30,6 @@ service Agent {
     rpc Get(CacheGetRequest) returns (CacheValue);
     rpc Set(CacheSetRequest) returns (SetStatus);
     rpc Shutdown(google.protobuf.Empty) returns (google.protobuf.Empty);
+    rpc Ping(google.protobuf.Empty) returns (google.protobuf.Empty);
 }
 

proto/agent_grpc.pb.go

@@ -1,8 +1,8 @@
 // Code generated by protoc-gen-go-grpc. DO NOT EDIT.
 // versions:
 // - protoc-gen-go-grpc v1.5.1
-// - protoc             v6.31.1
+// - protoc             v5.29.3
-// source: gitea.suyono.dev/suyono/go-agent/proto/agent.proto
+// source: agent.proto
 
 package proto
 
@@ -23,6 +23,7 @@ const (
 	Agent_Get_FullMethodName      = "/proto.Agent/Get"
 	Agent_Set_FullMethodName      = "/proto.Agent/Set"
 	Agent_Shutdown_FullMethodName = "/proto.Agent/Shutdown"
+	Agent_Ping_FullMethodName     = "/proto.Agent/Ping"
 )
 
 // AgentClient is the client API for Agent service.
@@ -32,6 +33,7 @@ type AgentClient interface {
 	Get(ctx context.Context, in *CacheGetRequest, opts ...grpc.CallOption) (*CacheValue, error)
 	Set(ctx context.Context, in *CacheSetRequest, opts ...grpc.CallOption) (*SetStatus, error)
 	Shutdown(ctx context.Context, in *emptypb.Empty, opts ...grpc.CallOption) (*emptypb.Empty, error)
+	Ping(ctx context.Context, in *emptypb.Empty, opts ...grpc.CallOption) (*emptypb.Empty, error)
 }
 
 type agentClient struct {
@@ -72,6 +74,16 @@ func (c *agentClient) Shutdown(ctx context.Context, in *emptypb.Empty, opts ...g
 	return out, nil
 }
 
+func (c *agentClient) Ping(ctx context.Context, in *emptypb.Empty, opts ...grpc.CallOption) (*emptypb.Empty, error) {
+	cOpts := append([]grpc.CallOption{grpc.StaticMethod()}, opts...)
+	out := new(emptypb.Empty)
+	err := c.cc.Invoke(ctx, Agent_Ping_FullMethodName, in, out, cOpts...)
+	if err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
 // AgentServer is the server API for Agent service.
 // All implementations must embed UnimplementedAgentServer
 // for forward compatibility.
@@ -79,6 +91,7 @@ type AgentServer interface {
 	Get(context.Context, *CacheGetRequest) (*CacheValue, error)
 	Set(context.Context, *CacheSetRequest) (*SetStatus, error)
 	Shutdown(context.Context, *emptypb.Empty) (*emptypb.Empty, error)
+	Ping(context.Context, *emptypb.Empty) (*emptypb.Empty, error)
 	mustEmbedUnimplementedAgentServer()
 }
 
@@ -98,6 +111,9 @@ func (UnimplementedAgentServer) Set(context.Context, *CacheSetRequest) (*SetStat
 func (UnimplementedAgentServer) Shutdown(context.Context, *emptypb.Empty) (*emptypb.Empty, error) {
 	return nil, status.Errorf(codes.Unimplemented, "method Shutdown not implemented")
 }
+func (UnimplementedAgentServer) Ping(context.Context, *emptypb.Empty) (*emptypb.Empty, error) {
+	return nil, status.Errorf(codes.Unimplemented, "method Ping not implemented")
+}
 func (UnimplementedAgentServer) mustEmbedUnimplementedAgentServer() {}
 func (UnimplementedAgentServer) testEmbeddedByValue()               {}
 
@@ -173,6 +189,24 @@ func _Agent_Shutdown_Handler(srv interface{}, ctx context.Context, dec func(inte
 	return interceptor(ctx, in, info, handler)
 }
 
+func _Agent_Ping_Handler(srv interface{}, ctx context.Context, dec func(interface{}) error, interceptor grpc.UnaryServerInterceptor) (interface{}, error) {
+	in := new(emptypb.Empty)
+	if err := dec(in); err != nil {
+		return nil, err
+	}
+	if interceptor == nil {
+		return srv.(AgentServer).Ping(ctx, in)
+	}
+	info := &grpc.UnaryServerInfo{
+		Server:     srv,
+		FullMethod: Agent_Ping_FullMethodName,
+	}
+	handler := func(ctx context.Context, req interface{}) (interface{}, error) {
+		return srv.(AgentServer).Ping(ctx, req.(*emptypb.Empty))
+	}
+	return interceptor(ctx, in, info, handler)
+}
+
 // Agent_ServiceDesc is the grpc.ServiceDesc for Agent service.
 // It's only intended for direct use with grpc.RegisterService,
 // and not to be introspected or modified (even as a copy)
@@ -192,7 +226,11 @@ var Agent_ServiceDesc = grpc.ServiceDesc{
 			MethodName: "Shutdown",
 			Handler:    _Agent_Shutdown_Handler,
 		},
+		{
+			MethodName: "Ping",
+			Handler:    _Agent_Ping_Handler,
+		},
 	},
 	Streams:  []grpc.StreamDesc{},
-	Metadata: "gitea.suyono.dev/suyono/go-agent/proto/agent.proto",
+	Metadata: "agent.proto",
 }

service/serve.go

@@ -19,9 +19,12 @@ limitations under the License.
 import (
 	"context"
 	"fmt"
+	"golang.org/x/sys/unix"
 	"net"
 	"os"
+	"os/exec"
 	"sync/atomic"
+	"syscall"
 	"time"
 
 	pb "gitea.suyono.dev/suyono/go-agent/proto"
@@ -32,8 +35,12 @@ import (
 
 type Option interface {
 	SocketPath() string
-	Expiry() string
 	StopGraceTime() time.Duration
+	Background() bool
+	ExecArgs() []string
+	ExecEnv() []string
+	ExecLogPath() string
+	Umask() int
 }
 
 type Storage interface {
@@ -42,6 +49,18 @@ type Storage interface {
 	Shutdown() error
 }
 
+type BgProcFlag int
+
+const (
+	child BgProcFlag = iota
+	parent
+)
+
+const (
+	goAgentDaemonEnvFlag = "GO_AGENT_DAEMON"
+	goAgentDaemonLogPath = "GO_AGENT_DAEMON_LOG"
+)
+
 type server struct {
 	pb.UnimplementedAgentServer
 	stor Storage
@@ -77,6 +96,48 @@ func (s *server) Shutdown(context.Context, *emptypb.Empty) (*emptypb.Empty, erro
 	return &emptypb.Empty{}, nil
 }
 
+func GetDaemonLogPath() (string, error) {
+	// The child process of the main program should call this function and set up the logging infrastructure
+	envVal, ok := os.LookupEnv(goAgentDaemonLogPath)
+	if !ok {
+		return "", fmt.Errorf("programming issue: parent process did not set log path")
+	}
+	return envVal, nil
+}
+
+func ExecBackground(opt Option) (BgProcFlag, error) {
+	var (
+		cmd    *exec.Cmd
+		ok     bool
+		envVal string
+	)
+
+	args := opt.ExecArgs()
+	envVal, ok = os.LookupEnv(goAgentDaemonEnvFlag)
+	if !opt.Background() || len(args) == 0 || (envVal == "1" && ok) {
+		return child, nil
+	}
+
+	if len(args) > 1 {
+		cmd = exec.Command(args[0], args[1:]...)
+	} else {
+		cmd = exec.Command(args[0])
+	}
+	cmd.Env = append(os.Environ(), fmt.Sprintf("%s=1", goAgentDaemonEnvFlag))
+	if opt.ExecLogPath() != "" {
+		cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", goAgentDaemonLogPath, opt.ExecLogPath()))
+	}
+	cmd.Env = append(cmd.Env, opt.ExecEnv()...)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setsid: true}
+	cmd.Stdin, cmd.Stdout, cmd.Stderr = nil, nil, nil
+
+	if err := cmd.Start(); err != nil {
+		return parent, err
+	}
+
+	return parent, nil
+}
+
 func Serve(ctx context.Context, opt Option) error {
 	var (
 		l      net.Listener
@@ -85,18 +146,30 @@ func Serve(ctx context.Context, opt Option) error {
 		ok     bool
 		sw     *atomic.Bool
 		cancel context.CancelFunc
+		bgFlag BgProcFlag
 	)
-	socketPath := opt.SocketPath()
-	os.Remove(socketPath)
 
-	if l, err = net.Listen("unix", socketPath); err != nil {
+	if bgFlag, err = ExecBackground(opt); err != nil {
-		return fmt.Errorf("failed to listen on unix socket: %w", err)
+		return fmt.Errorf("could not start background process: %w", err)
+	}
+	if bgFlag == parent {
+		return nil
 	}
 
+	_ = os.Remove(opt.SocketPath())
+
+	oldUmask := unix.Umask(opt.Umask())
+	if l, err = net.Listen("unix", opt.SocketPath()); err != nil {
+		return fmt.Errorf("failed to listen on unix socket: %w", err)
+	}
+	unix.Umask(oldUmask)
+
 	grpcServer := grpc.NewServer()
-	pb.RegisterAgentServer(grpcServer, &server{stor: storage.NewInMap()})
-	errChan := make(chan error, 1)
 	ctx, cancel = context.WithCancel(ctx)
+	pb.RegisterAgentServer(grpcServer, &server{
+		stor: storage.NewInMap(cancel),
+	})
+	errChan := make(chan error, 1)
 	sw = new(atomic.Bool)
 	sw.Store(false)
 
@@ -137,3 +210,7 @@ fsl:
 
 	return err
 }
+
+func (s *server) Ping(ctx context.Context, req *emptypb.Empty) (*emptypb.Empty, error) {
+	return &emptypb.Empty{}, nil
+}

storage/inmap.go

@@ -16,17 +16,22 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import "sync"
+import (
+	"context"
+	"sync"
+)
 
 type InMap struct {
-	mtx  *sync.Mutex
+	mtx    *sync.Mutex
-	stor map[string]string
+	stor   map[string]string
+	cancel context.CancelFunc
 }
 
-func NewInMap() *InMap {
+func NewInMap(ctxCancel context.CancelFunc) *InMap {
 	return &InMap{
-		mtx:  new(sync.Mutex),
+		mtx:    new(sync.Mutex),
-		stor: make(map[string]string),
+		stor:   make(map[string]string),
+		cancel: ctxCancel,
 	}
 }
 
@@ -56,5 +61,6 @@ func (i *InMap) Get(key string) (string, error) {
 }
 
 func (i *InMap) Shutdown() error {
+	i.cancel()
 	return nil
 }