Implement daemon mode (#119)

* add daemon process
* add daemon stop command
* add daemon log to log file
* check for running daemons
* minor changes

assets/config/photoprism.yml

@@ -15,3 +15,6 @@ http-port: 80
 http-password:
 database-driver: internal
 database-dsn: root:photoprism@tcp(localhost:4000)/photoprism?parseTime=true
+daemon-pid-path: /srv/photoprism/photoprism.pid
+daemon-log-path: /srv/photoprism/photoprism.log
+daemon-mode: false

cmd/photoprism/photoprism.go

@@ -23,6 +23,7 @@ func main() {
 	app.Commands = []cli.Command{
 		commands.ConfigCommand,
 		commands.StartCommand,
+		commands.StopCommand,
 		commands.MigrateCommand,
 		commands.ImportCommand,
 		commands.IndexCommand,

go.mod

@@ -36,10 +36,12 @@ require (
 	github.com/pingcap/tidb-tools v2.1.3-0.20190116051332-34c808eef588+incompatible
 	github.com/pkg/errors v0.8.1
 	github.com/prometheus/client_golang v0.9.3-0.20190127221311-3c4408c8b829
+	github.com/prometheus/common v0.2.0
 	github.com/rainycape/unidecode v0.0.0-20150907023854-cb7f23ec59be // indirect
 	github.com/remyoudompheng/bigfft v0.0.0-20170806203942-52369c62f446 // indirect
 	github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd
 	github.com/satori/go.uuid v1.2.0
+	github.com/sevlyar/go-daemon v0.1.5
 	github.com/simplereach/timeutils v1.2.0 // indirect
 	github.com/sirupsen/logrus v1.2.0
 	github.com/soheilhy/cmux v0.1.4 // indirect

go.sum

@@ -257,6 +257,8 @@ github.com/rwcarlsen/goexif v0.0.0-20190401172101-9e8deecbddbd/go.mod h1:hPqNNc0
 github.com/rwcarlsen/goexif v0.0.0-20190501182100-9e8deecbddbd4989a3e8d003684b783412b41e7a/go.mod h1:hPqNNc0+uJM6H+SuU8sEs5K5IQeKccPqeSjfgcKGgPk=
 github.com/satori/go.uuid v1.2.0 h1:0uYX9dsZ2yD7q2RtLRtPSdGDWzjeM3TbMJP9utgA0ww=
 github.com/satori/go.uuid v1.2.0/go.mod h1:dA0hQrYB0VpLJoorglMZABFdXlWrHn1NEOzdhQKdks0=
+github.com/sevlyar/go-daemon v0.1.5 h1:Zy/6jLbM8CfqJ4x4RPr7MJlSKt90f00kNM1D401C+Qk=
+github.com/sevlyar/go-daemon v0.1.5/go.mod h1:6dJpPatBT9eUwM5VCw9Bt6CdX9Tk6UWvhW3MebLDRKE=
 github.com/simplereach/timeutils v1.2.0 h1:btgOAlu9RW6de2r2qQiONhjgxdAG7BL6je0G6J/yPnA=
 github.com/simplereach/timeutils v1.2.0/go.mod h1:VVbQDfN/FHRZa1LSqcwo4kNZ62OOyqLLGQKYB3pB0Q8=
 github.com/sirupsen/logrus v0.0.0-20170323161349-3bcb09397d6d/go.mod h1:pMByvHTf9Beacp5x1UXfOR9xyW/9antXMhjMPG0dEzc=

internal/commands/start.go

@@ -4,13 +4,15 @@ import (
 	"context"
 	"os"
 	"os/signal"
+	"strconv"
 	"syscall"
 	"time"
 
-	log "github.com/sirupsen/logrus"
-
 	"github.com/photoprism/photoprism/internal/config"
 	"github.com/photoprism/photoprism/internal/server"
+	"github.com/photoprism/photoprism/internal/util"
+	daemon "github.com/sevlyar/go-daemon"
+	log "github.com/sirupsen/logrus"
 	"github.com/urfave/cli"
 )
 
@@ -41,6 +43,12 @@ var startFlags = []cli.Flag{
 		Value:  "",
 		EnvVar: "PHOTOPRISM_HTTP_MODE",
 	},
+
+	cli.BoolFlag{
+		Name:   "daemonize, d",
+		Usage:  "run Photoprism as Daemon",
+		EnvVar: "PHOTOPRISM_DAEMON_MODE",
+	},
 }
 
 func startAction(ctx *cli.Context) error {
@@ -60,6 +68,33 @@ func startAction(ctx *cli.Context) error {
 	}
 	conf.MigrateDb()
 
+	dctx := new(daemon.Context)
+	dctx.LogFileName = conf.DaemonLogPath()
+	dctx.PidFileName = conf.DaemonPIDPath()
+	dctx.Args = ctx.Args()
+	if !daemon.WasReborn() && conf.ShouldDaemonize() {
+		conf.Shutdown()
+		cancel()
+
+		if pid, ok := childAlreadyRunning(conf.DaemonPIDPath()); ok {
+			log.Infof("Daemon already running with PID[%v]\n", pid)
+			return nil
+		}
+
+		child, err := dctx.Reborn()
+		if err != nil {
+			log.Fatal(err)
+		}
+
+		if child != nil {
+			if !util.Overwrite(conf.DaemonPIDPath(), []byte(strconv.Itoa(child.Pid))) {
+				log.Fatal("failed to write PID to file")
+			}
+
+			log.Infof("Daemon started with PID: %v\n", child.Pid)
+			return nil
+		}
+	}
 	log.Infof("starting web server at %s:%d", conf.HttpServerHost(), conf.HttpServerPort())
 	go server.Start(cctx, conf)
 
@@ -70,6 +105,28 @@ func startAction(ctx *cli.Context) error {
 	log.Info("Shutting down...")
 	conf.Shutdown()
 	cancel()
+	err := dctx.Release()
+	if err != nil {
+		log.Error(err)
+	}
 	time.Sleep(3 * time.Second)
 	return nil
 }
+
+func childAlreadyRunning(filePath string) (pid int, running bool) {
+	if !util.Exists(filePath) {
+		return pid, false
+	}
+
+	pid, err := daemon.ReadPidFile(filePath)
+	if err != nil {
+		return pid, false
+	}
+
+	process, err := os.FindProcess(int(pid))
+	if err != nil {
+		return pid, false
+	}
+
+	return pid, process.Signal(syscall.Signal(0)) == nil
+}

internal/commands/stop.go

@@ -0,0 +1,42 @@
+package commands
+
+import (
+	"syscall"
+
+	"github.com/photoprism/photoprism/internal/config"
+	"github.com/prometheus/common/log"
+	daemon "github.com/sevlyar/go-daemon"
+	"github.com/urfave/cli"
+)
+
+// StopCommand stops the daemon if any.
+var StopCommand = cli.Command{
+	Name:   "stop",
+	Usage:  "Stops daemon",
+	Action: stopAction,
+}
+
+func stopAction(ctx *cli.Context) error {
+	conf := config.NewConfig(ctx)
+	log.Infof("Looking for PID from file: %v\n", conf.DaemonPIDPath())
+	dcxt := new(daemon.Context)
+	dcxt.PidFileName = conf.DaemonPIDPath()
+	child, err := dcxt.Search()
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	err = child.Signal(syscall.SIGTERM)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	st, err := child.Wait()
+	if err != nil {
+		log.Info("Daemon exited successfully")
+		return nil
+	}
+
+	log.Infof("Daemon[%v] exited[%v]? successfully[%v]?\n", st.Pid(), st.Exited(), st.Success())
+	return nil
+}

internal/config/config.go

@@ -218,6 +218,29 @@ func (c *Config) ConfigPath() string {
 	return c.config.ConfigPath
 }
 
+// DaemonPIDPath returns the filepath of the pid.
+func (c *Config) DaemonPIDPath() string {
+	if c.config.DaemonPIDPath == "" {
+		return c.AssetsPath() + "/photoprism.pid"
+	}
+
+	return c.config.DaemonPIDPath
+}
+
+// DaemonLogPath returns the filepath of the log.
+func (c *Config) DaemonLogPath() string {
+	if c.config.DaemonLogPath == "" {
+		return c.AssetsPath() + "/photoprism.log"
+	}
+
+	return c.config.DaemonLogPath
+}
+
+// ShouldDaemonize returns true if daemon mode is set to true.
+func (c *Config) ShouldDaemonize() bool {
+	return c.config.DaemonMode
+}
+
 // SqlServerHost returns the built-in SQL server host name or IP address (empty for all interfaces).
 func (c *Config) SqlServerHost() string {
 	return c.config.SqlServerHost

internal/config/flags.go

@@ -1,6 +1,8 @@
 package config
 
-import "github.com/urfave/cli"
+import (
+	"github.com/urfave/cli"
+)
 
 // Global CLI flags
 var GlobalFlags = []cli.Flag{
@@ -150,4 +152,21 @@ var GlobalFlags = []cli.Flag{
 		Value:  "heif-convert",
 		EnvVar: "PHOTOPRISM_HEIFCONVERT_BIN",
 	},
+	cli.StringFlag{
+		Name:   "daemon-pid-path",
+		Usage:  "File path to store daemon PID",
+		EnvVar: "PHOTOPRISM_DAEMON_PID_PATH",
+		Value:  "/srv/photoprism/photoprism.pid",
+	},
+	cli.StringFlag{
+		Name:   "daemon-log-path",
+		Usage:  "File path for daemon logs.",
+		EnvVar: "PHOTOPRISM_DAEMON_LOG_PATH",
+		Value:  "/srv/photoprism/photoprism.log",
+	},
+	cli.BoolFlag{
+		Name:   "daemonize, d",
+		Usage:  "run Photoprism as Daemon",
+		EnvVar: "PHOTOPRISM_DAEMON_MODE",
+	},
 }

internal/config/params.go

@@ -56,6 +56,9 @@ type Params struct {
 	DarktableBin       string `yaml:"darktable-bin" flag:"darktable-bin"`
 	ExifToolBin        string `yaml:"exiftool-bin" flag:"exiftool-bin"`
 	HeifConvertBin     string `yaml:"heifconvert-bin" flag:"heifconvert-bin"`
+	DaemonPIDPath      string `yaml:"daemon-pid-path" flag:"daemon-pid-path"`
+	DaemonLogPath      string `yaml:"daemon-log-path" flag:"daemon-log-path"`
+	DaemonMode         bool   `yaml:"daemon-mode" flag:"daemonize"`
 }
 
 // NewParams() creates a new configuration entity by using two methods:

internal/photoprism/openstreetmap.go

@@ -92,8 +92,8 @@ func (m *MediaFile) Location() (*models.Location, error) {
 	}
 
 	if len(openstreetmapLocation.Name) > 1 {
-		location.LocName = strings.ReplaceAll(openstreetmapLocation.Name, " - ", " / ")
+		location.LocName = strings.Replace(openstreetmapLocation.Name, " - ", " / ", -1)
-		location.LocName = util.Title(strings.TrimSpace(strings.ReplaceAll(location.LocName, "_", " ")))
+		location.LocName = util.Title(strings.TrimSpace(strings.Replace(location.LocName, "_", " ", -1)))
 	}
 
 	location.LocHouseNr = strings.TrimSpace(openstreetmapLocation.Address.HouseNumber)
@@ -106,11 +106,11 @@ func (m *MediaFile) Location() (*models.Location, error) {
 	location.LocCountryCode = strings.TrimSpace(openstreetmapLocation.Address.CountryCode)
 	location.LocDisplayName = strings.TrimSpace(openstreetmapLocation.DisplayName)
 
-	locationCategory := strings.TrimSpace(strings.ReplaceAll(openstreetmapLocation.Category, "_", " "))
+	locationCategory := strings.TrimSpace(strings.Replace(openstreetmapLocation.Category, "_", " ", -1))
 	location.LocCategory = locationCategory
 
 	if openstreetmapLocation.Type != "yes" && openstreetmapLocation.Type != "unclassified" {
-		locationType := strings.TrimSpace(strings.ReplaceAll(openstreetmapLocation.Type, "_", " "))
+		locationType := strings.TrimSpace(strings.Replace(openstreetmapLocation.Type, "_", " ", -1))
 		location.LocType = locationType
 	}
 

internal/util/file.go

@@ -18,6 +18,17 @@ func Exists(filename string) bool {
 	return err == nil && !info.IsDir()
 }
 
+// Overwrite overwrites the file with data. Creates file if not present.
+func Overwrite(fileName string, data []byte) bool {
+	f, err := os.Create(fileName)
+	if err != nil {
+		return false
+	}
+
+	_, err = f.Write(data)
+	return err == nil
+}
+
 // Returns full path; ~ replaced with actual home directory
 func ExpandedFilename(filename string) string {
 	if filename == "" {