WIP: logging in the background process

go.mod

@@ -3,6 +3,9 @@ module gitea.suyono.dev/suyono/go-agent
 go 1.24
 
 require (
+	github.com/mattn/go-colorable v0.1.14 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/rs/zerolog v1.34.0 // indirect
 	golang.org/x/net v0.41.0 // indirect
 	golang.org/x/sys v0.33.0 // indirect
 	golang.org/x/text v0.26.0 // indirect

go.sum

@@ -1,5 +1,21 @@
+github.com/coreos/go-systemd/v22 v22.5.0/go.mod h1:Y58oyj3AT4RCenI/lSvhwexgC+NSVTIJ3seZv2GcEnc=
+github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
+github.com/mattn/go-colorable v0.1.13/go.mod h1:7S9/ev0klgBDR4GtXTXX8a3vIGJpMovkB8vQcUbaXHg=
+github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
+github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
+github.com/mattn/go-isatty v0.0.16/go.mod h1:kYGgaQfpe5nmfYZH+SKPsOc2e4SrIfOl2e/yFXSvRLM=
+github.com/mattn/go-isatty v0.0.19/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
+github.com/mattn/go-isatty v0.0.20/go.mod h1:W+V8PltTTMOvKvAeJH7IuucS94S2C6jfK/D7dTCTo3Y=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+github.com/rs/xid v1.6.0/go.mod h1:7XoLgs4eV+QndskICGsho+ADou8ySMSjJKDIan90Nz0=
+github.com/rs/zerolog v1.34.0 h1:k43nTLIwcTVQAncfCw4KZ2VY6ukYoZaBPNOE8txlOeY=
+github.com/rs/zerolog v1.34.0/go.mod h1:bJsvje4Z08ROH4Nhs5iH600c3IkWhwp44iRc54W6wYQ=
 golang.org/x/net v0.41.0 h1:vBTly1HeNPEn3wtREYfy4GZ/NECgw2Cnl+nK6Nz3uvw=
 golang.org/x/net v0.41.0/go.mod h1:B/K4NNqkfmg07DQYrbwvSluqCJOOXwUjeb/5lOisjbA=
+golang.org/x/sys v0.0.0-20220811171246-fbc7d0a398ab/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/sys v0.12.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/sys v0.33.0 h1:q3i8TbbEz+JRD9ywIRlyRAQbM0qF7hu24q3teo2hbuw=
 golang.org/x/sys v0.33.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
 golang.org/x/text v0.26.0 h1:P42AVeLghgTYr4+xUnTRKDMqpar+PtX7KWuNQL21L8M=

service/serve.go

@@ -29,6 +29,9 @@ import (
 
 	pb "gitea.suyono.dev/suyono/go-agent/proto"
 	"gitea.suyono.dev/suyono/go-agent/storage"
+	"github.com/rs/zerolog"
+	"github.com/rs/zerolog/diode"
+	"github.com/rs/zerolog/log"
 	"google.golang.org/grpc"
 	"google.golang.org/protobuf/types/known/emptypb"
 )
@@ -82,6 +85,7 @@ func (s *server) Get(ctx context.Context, req *pb.CacheGetRequest) (*pb.CacheVal
 func (s *server) Set(ctx context.Context, req *pb.CacheSetRequest) (*pb.SetStatus, error) {
 	err := s.stor.Set(req.GetKey(), req.GetValue())
 	if err != nil {
+		log.Error().Err(err).Caller().Msg("failed to set cache")
 		return nil, err
 	}
 	return &pb.SetStatus{
@@ -96,42 +100,53 @@ 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
+		cmd     *exec.Cmd
-		ok     bool
+		envVal  string
-		envVal string
+		logPath string
+		err     error
+		f       *os.File
 	)
 
 	args := opt.ExecArgs()
-	envVal, ok = os.LookupEnv(goAgentDaemonEnvFlag)
+	envVal = os.Getenv(goAgentDaemonEnvFlag)
-	if !opt.Background() || len(args) == 0 || (envVal == "1" && ok) {
+	if !opt.Background() || len(args) == 0 || envVal == "1" {
+		if envVal == "1" {
+			logPath = os.Getenv(goAgentDaemonLogPath)
+			if logPath == "" {
+				panic(fmt.Errorf("cannot start background process without log path"))
+			}
+
+			if f, err = os.OpenFile(logPath, os.O_WRONLY|os.O_CREATE|os.O_APPEND, 0600); err != nil {
+				panic(fmt.Errorf("opening log file: %w", err))
+			}
+
+			log.Logger = zerolog.New(diode.NewWriter(f, 1000, 10*time.Millisecond, func(missed int) {
+				fmt.Printf("Logger Dropped %d messages", missed)
+			}))
+		}
+
 		return child, nil
 	}
 
+	if opt.ExecLogPath() == "" {
+		return parent, fmt.Errorf("cannot start background process without log path")
+	}
+
 	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))
+	cmd.Env = append(os.Environ(), opt.ExecEnv()...)
-	if opt.ExecLogPath() != "" {
+	cmd.Env = append(cmd.Env,
-		cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", goAgentDaemonLogPath, opt.ExecLogPath()))
+		fmt.Sprintf("%s=1", goAgentDaemonEnvFlag),
-	}
+		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 {
+	if err = cmd.Start(); err != nil {
 		return parent, err
 	}