portable mode: advertise service via multicast dns

Fixes #51

README.md

@@ -292,14 +292,29 @@ Usage:
   sftpgo portable [flags]
 
 Flags:
-  -d, --directory string      Path to the directory to serve. This can be an absolute path or a path relative to the current directory (default ".")
-  -h, --help                  help for portable
-  -p, --password string       Leave empty to use an auto generated value
-  -g, --permissions strings   User's permissions. "*" means any permission (default [list,download])
+  -C, --advertise-credentials   If the service is advertised via multicast DNS this flag allows to put username/password inside the advertised TXT record
+  -S, --advertise-service       Advertise SFTP/SCP service using multicast DNS (default true)
+  -d, --directory string        Path to the directory to serve. This can be an absolute path or a path relative to the current directory (default ".")
+  -h, --help                    help for portable
+  -l, --log-file-path string    Leave empty to disable logging
+  -p, --password string         Leave empty to use an auto generated value
+  -g, --permissions strings     User's permissions. "*" means any permission (default [list,download])
   -k, --public-key strings
-      --scp                   Enable SCP
-  -s, --sftpd-port int        0 means a random non privileged port
-  -u, --username string       Leave empty to use an auto generated value
+      --scp                     Enable SCP
+  -s, --sftpd-port int          0 means a random non privileged port
+  -u, --username string         Leave empty to use an auto generated value
+```
+
+In portable mode SFTPGo can advertise the SFTP service and, optionally, the credentials via multicast DNS, so there is a standard way to discover the service and to automatically connect to it.
+
+Here is an example of the advertised service including credentials as seen using `avahi-browse`:
+
+```
+= enp0s31f6 IPv4 SFTPGo portable 53705                         SFTP File Transfer   local
+   hostname = [p1.local]
+   address = [192.168.1.230]
+   port = [53705]
+   txt = ["password=EWOo6pJe" "user=user" "version=0.9.3-dev-b409523-dirty-2019-10-26T13:43:32Z"]
 ```
 
 ## Account's configuration properties
@@ -448,6 +463,7 @@ The logs can be divided into the following categories:
 - [cobra](https://github.com/spf13/cobra)
 - [xid](https://github.com/rs/xid)
 - [nathanaelle/password](https://github.com/nathanaelle/password)
+- [ZeroConf](https://github.com/grandcat/zeroconf)
 - [SB Admin 2](https://github.com/BlackrockDigital/startbootstrap-sb-admin-2)
 
 Some code was initially taken from [Pterodactyl sftp server](https://github.com/pterodactyl/sftp-server)

cmd/portable.go

@@ -9,14 +9,17 @@ import (
 )
 
 var (
-	directoryToServe    string
-	portableSFTPDPort   int
-	portableEnableSCP   bool
-	portableUsername    string
-	portablePassword    string
-	portablePublicKeys  []string
-	portablePermissions []string
-	portableCmd         = &cobra.Command{
+	directoryToServe             string
+	portableSFTPDPort            int
+	portableEnableSCP            bool
+	portableAdvertiseService     bool
+	portableAdvertiseCredentials bool
+	portableUsername             string
+	portablePassword             string
+	portableLogFile              string
+	portablePublicKeys           []string
+	portablePermissions          []string
+	portableCmd                  = &cobra.Command{
 		Use:   "portable",
 		Short: "Serve a single directory",
 		Long: `To serve the current working directory with auto generated credentials simply use:
@@ -32,7 +35,7 @@ Please take a look at the usage below to customize the serving parameters`,
 			service := service.Service{
 				ConfigDir:     defaultConfigDir,
 				ConfigFile:    defaultConfigName,
-				LogFilePath:   defaultLogFile,
+				LogFilePath:   portableLogFile,
 				LogMaxSize:    defaultLogMaxSize,
 				LogMaxBackups: defaultLogMaxBackup,
 				LogMaxAge:     defaultLogMaxAge,
@@ -48,7 +51,8 @@ Please take a look at the usage below to customize the serving parameters`,
 					HomeDir:     portableDir,
 				},
 			}
-			if err := service.StartPortableMode(portableSFTPDPort, portableEnableSCP); err == nil {
+			if err := service.StartPortableMode(portableSFTPDPort, portableEnableSCP, portableAdvertiseService,
+				portableAdvertiseCredentials); err == nil {
 				service.Wait()
 			}
 		},
@@ -59,11 +63,16 @@ func init() {
 	portableCmd.Flags().StringVarP(&directoryToServe, "directory", "d", ".",
 		"Path to the directory to serve. This can be an absolute path or a path relative to the current directory")
 	portableCmd.Flags().IntVarP(&portableSFTPDPort, "sftpd-port", "s", 0, "0 means a random non privileged port")
-	portableCmd.Flags().BoolVarP(&portableEnableSCP, "scp", "", false, "Enable SCP")
+	portableCmd.Flags().BoolVar(&portableEnableSCP, "scp", false, "Enable SCP")
 	portableCmd.Flags().StringVarP(&portableUsername, "username", "u", "", "Leave empty to use an auto generated value")
 	portableCmd.Flags().StringVarP(&portablePassword, "password", "p", "", "Leave empty to use an auto generated value")
+	portableCmd.Flags().StringVarP(&portableLogFile, logFilePathFlag, "l", "", "Leave empty to disable logging")
 	portableCmd.Flags().StringSliceVarP(&portablePublicKeys, "public-key", "k", []string{}, "")
 	portableCmd.Flags().StringSliceVarP(&portablePermissions, "permissions", "g", []string{"list", "download"},
 		"User's permissions. \"*\" means any permission")
+	portableCmd.Flags().BoolVarP(&portableAdvertiseService, "advertise-service", "S", true,
+		"Advertise SFTP/SCP service using multicast DNS")
+	portableCmd.Flags().BoolVarP(&portableAdvertiseCredentials, "advertise-credentials", "C", false,
+		"If the service is advertised via multicast DNS this flag allows to put username/password inside the advertised TXT record")
 	rootCmd.AddCommand(portableCmd)
 }

go.mod

@@ -4,19 +4,19 @@ go 1.12
 
 require (
 	github.com/alexedwards/argon2id v0.0.0-20190612080829-01a59b2b8802
+	github.com/cenkalti/backoff v2.2.1+incompatible // indirect
 	github.com/go-chi/chi v4.0.2+incompatible
 	github.com/go-chi/render v1.0.1
 	github.com/go-sql-driver/mysql v1.4.1
+	github.com/grandcat/zeroconf v0.0.0-20190424104450-85eadb44205c
 	github.com/lib/pq v1.2.0
 	github.com/magiconair/properties v1.8.1 // indirect
 	github.com/mattn/go-sqlite3 v1.11.0
+	github.com/miekg/dns v1.1.22 // indirect
 	github.com/nathanaelle/password v1.0.0
-	github.com/pelletier/go-toml v1.5.0 // indirect
+	github.com/pelletier/go-toml v1.6.0 // indirect
 	github.com/pkg/sftp v1.10.2-0.20191014030235-4350932b9896
-	github.com/prometheus/client_golang v1.1.0
-	github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 // indirect
-	github.com/prometheus/common v0.7.0 // indirect
-	github.com/prometheus/procfs v0.0.5 // indirect
+	github.com/prometheus/client_golang v1.2.1
 	github.com/rs/xid v1.2.1
 	github.com/rs/zerolog v1.15.0
 	github.com/spf13/afero v1.2.2 // indirect
@@ -26,8 +26,8 @@ require (
 	github.com/spf13/viper v1.4.0
 	go.etcd.io/bbolt v1.3.3
 	golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550
-	golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297 // indirect
-	golang.org/x/sys v0.0.0-20191010194322-b09406accb47
+	golang.org/x/net v0.0.0-20191021144547-ec77196f6094 // indirect
+	golang.org/x/sys v0.0.0-20191026070338-33540a1f6037
 	google.golang.org/appengine v1.6.5 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0
 )

go.sum

@@ -13,7 +13,12 @@ github.com/beorn7/perks v0.0.0-20180321164747-3a771d992973/go.mod h1:Dwedo/Wpr24
 github.com/beorn7/perks v1.0.0/go.mod h1:KWe93zE9D1o94FZ5RNwFwVgaQK1VOXiVxmqh+CedLV8=
 github.com/beorn7/perks v1.0.1 h1:VlbKKnNfV8bJzeqoa4cOKqO6bYr3WgKZxO8Z16+hsOM=
 github.com/beorn7/perks v1.0.1/go.mod h1:G2ZrVWU2WbWT9wwq4/hrbKbnv/1ERSJQ0ibhJ6rlkpw=
+github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
+github.com/cenkalti/backoff v2.2.1+incompatible/go.mod h1:90ReRw6GdpyfrHakVjL/QHaoyV4aDUVVkXQJJJ3NXXM=
+github.com/cespare/xxhash v1.1.0 h1:a6HrQnmkObjyL+Gs60czilIUGqrzKutQD6XZog3p+ko=
 github.com/cespare/xxhash v1.1.0/go.mod h1:XrSqR1VqqWfGrhpAt58auRo0WTKS1nRRg3ghfAqPWnc=
+github.com/cespare/xxhash/v2 v2.1.0 h1:yTUvW7Vhb89inJ+8irsUqiWjh8iT6sQPZiQzI6ReGkA=
+github.com/cespare/xxhash/v2 v2.1.0/go.mod h1:dgIUBU3pDso/gPgZ1osOZ0iQf77oPR28Tjxl5dIMyVM=
 github.com/client9/misspell v0.3.4/go.mod h1:qj6jICC3Q7zFZvVWo7KLAzC3yx5G7kyvSDkc90ppPyw=
 github.com/coreos/bbolt v1.3.2/go.mod h1:iRUV2dpdMOn7Bo10OQBFzIJO9kkE559Wcmn+qkEiiKk=
 github.com/coreos/etcd v3.3.10+incompatible/go.mod h1:uF7uidLiAD3TWHmW31ZFd/JWoc32PjwdhPthX9715RE=
@@ -56,6 +61,8 @@ github.com/google/go-cmp v0.3.0 h1:crn/baboCvb5fXaQ0IJ1SGTsTVrWpDsCWC8EGETZijY=
 github.com/google/go-cmp v0.3.0/go.mod h1:8QqcDgzrUqlUb/G2PQTWiueGozuR1884gddMywk6iLU=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/websocket v1.4.0/go.mod h1:E7qHFY5m1UJ88s3WnNqhKjPHQ0heANvMoAMk2YaljkQ=
+github.com/grandcat/zeroconf v0.0.0-20190424104450-85eadb44205c h1:svzQzfVE9t7Y1CGULS5PsMWs4/H4Au/ZTJzU/0CKgqc=
+github.com/grandcat/zeroconf v0.0.0-20190424104450-85eadb44205c/go.mod h1:YjKB0WsLXlMkO9p+wGTCoPIDGRJH0mz7E526PxkQVxI=
 github.com/grpc-ecosystem/go-grpc-middleware v1.0.0/go.mod h1:FiyG127CGDf3tlThmgyCl78X/SZQqEOJBCDaAfeWzPs=
 github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0/go.mod h1:8NvIoxWQoOIhqOTXgfV/d3M/q6VIi02HzZEHgUlZvzk=
 github.com/grpc-ecosystem/grpc-gateway v1.9.0/go.mod h1:vNeuVxBJEsws4ogUvrchl83t/GYV9WGTSLVdBhOQFDY=
@@ -87,6 +94,8 @@ github.com/mattn/go-sqlite3 v1.11.0 h1:LDdKkqtYlom37fkvqs8rMPFKAMe8+SgjbwZ6ex1/A
 github.com/mattn/go-sqlite3 v1.11.0/go.mod h1:FPy6KqzDD04eiIsT53CuJW3U88zkxoIYsOqkbpncsNc=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
+github.com/miekg/dns v1.1.22 h1:Jm64b3bO9kP43ddLjL2EY3Io6bmy1qGb9Xxz6TqS6rc=
+github.com/miekg/dns v1.1.22/go.mod h1:bPDLeHnStXmXAq1m/Ch/hvfNHr14JKNPMBo3VZKjuso=
 github.com/mitchellh/go-homedir v1.1.0/go.mod h1:SfyaCUpYCn1Vlf4IUYiD9fPX4A5wJrkLzIz1N1q0pr0=
 github.com/mitchellh/mapstructure v1.1.2 h1:fmNYVwqnSfB9mZU6OS2O6GsXM+wcskZDuKQzvN1EDeE=
 github.com/mitchellh/mapstructure v1.1.2/go.mod h1:FVVH3fgwuzCH5S8UJGiWEs2h04kUh9fWfEaFds41c1Y=
@@ -99,8 +108,8 @@ github.com/nathanaelle/password v1.0.0 h1:1Etka3uuBvATlCb72f7P5vsgedus+C91Fgff1o
 github.com/nathanaelle/password v1.0.0/go.mod h1:wt9xV3xwQmc3Qi0ofowmzR7N+kF1L4cguCuWjAfdj1Q=
 github.com/oklog/ulid v1.3.1/go.mod h1:CirwcVhetQ6Lv90oh/F+FBtV6XMibvdAFo93nm5qn4U=
 github.com/pelletier/go-toml v1.2.0/go.mod h1:5z9KED0ma1S8pY6P1sdut58dfprrGBbd/94hg7ilaic=
-github.com/pelletier/go-toml v1.5.0 h1:5BakdOZdtKJ1FFk6QdL8iSGrMWsXgchNJcrnarjbmJQ=
-github.com/pelletier/go-toml v1.5.0/go.mod h1:5N711Q9dKgbdkxHL+MEfF31hpT7l0S0s/t2kKREewys=
+github.com/pelletier/go-toml v1.6.0 h1:aetoXYr0Tv7xRU/V4B4IZJ2QcbtMUFoNb3ORp7TzIK4=
+github.com/pelletier/go-toml v1.6.0/go.mod h1:5N711Q9dKgbdkxHL+MEfF31hpT7l0S0s/t2kKREewys=
 github.com/pkg/errors v0.8.0/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
 github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
@@ -111,8 +120,8 @@ github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZN
 github.com/prometheus/client_golang v0.9.1/go.mod h1:7SWBe2y4D6OKWSNQJUaRYU/AaXPKyh/dDVn+NZz0KFw=
 github.com/prometheus/client_golang v0.9.3/go.mod h1:/TN21ttK/J9q6uSwhBd54HahCDft0ttaMvbicHlPoso=
 github.com/prometheus/client_golang v1.0.0/go.mod h1:db9x61etRT2tGnBNRi70OPL5FsnadC4Ky3P0J6CfImo=
-github.com/prometheus/client_golang v1.1.0 h1:BQ53HtBmfOitExawJ6LokA4x8ov/z0SYYb0+HxJfRI8=
-github.com/prometheus/client_golang v1.1.0/go.mod h1:I1FGZT9+L76gKKOs5djB6ezCbFQP1xR9D75/vuwEF3g=
+github.com/prometheus/client_golang v1.2.1 h1:JnMpQc6ppsNgw9QPAGF6Dod479itz7lvlsMzzNayLOI=
+github.com/prometheus/client_golang v1.2.1/go.mod h1:XMU6Z2MjaRKVu/dC1qupJI9SiNkDYzz3xecMgSW/F+U=
 github.com/prometheus/client_model v0.0.0-20180712105110-5c3871d89910/go.mod h1:MbSGuTsp3dbXC40dX6PRTWyKYBIrTGTE9sqQNg2J8bo=
 github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4 h1:gQz4mCbXsO+nc9n1hCxHcGA3Zx3Eo+UHZoInFGUIXNM=
@@ -120,13 +129,11 @@ github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:
 github.com/prometheus/common v0.0.0-20181113130724-41aa239b4cce/go.mod h1:daVV7qP5qjZbuso7PdcryaAu0sAZbrN9i7WWcTMWvro=
 github.com/prometheus/common v0.4.0/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
 github.com/prometheus/common v0.4.1/go.mod h1:TNfzLD0ON7rHzMJeJkieUDPYmFC7Snx/y86RQel1bk4=
-github.com/prometheus/common v0.6.0/go.mod h1:eBmuwkDJBwy6iBfxCBob6t6dR6ENT/y+J+Zk0j9GMYc=
 github.com/prometheus/common v0.7.0 h1:L+1lyG48J1zAQXA3RBX/nG/B3gjlHq0zTt2tlbJLyCY=
 github.com/prometheus/common v0.7.0/go.mod h1:DjGbpBbp5NYNiECxcL/VnbXCCaQpKd3tt26CguLLsqA=
 github.com/prometheus/procfs v0.0.0-20181005140218-185b4288413d/go.mod h1:c3At6R/oaqEKCNdg8wHV1ftS6bRYblBhIjjI8uT2IGk=
 github.com/prometheus/procfs v0.0.0-20190507164030-5867b95ac084/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
 github.com/prometheus/procfs v0.0.2/go.mod h1:TjEm7ze935MbeOT/UhFTIMYKhuLP4wbCsTZCD3I8kEA=
-github.com/prometheus/procfs v0.0.3/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
 github.com/prometheus/procfs v0.0.5 h1:3+auTFlqw+ZaQYJARz6ArODtkaIwtvBTx3N2NehQlL8=
 github.com/prometheus/procfs v0.0.5/go.mod h1:4A/X28fw3Fc593LaREMrKMqOKvUAntwMDaekg4FpcdQ=
 github.com/prometheus/tsdb v0.7.1/go.mod h1:qhTCs0VvXwvX/y3TZrWD7rabWM+ijKTux40TwIPHuXU=
@@ -179,6 +186,7 @@ golang.org/x/crypto v0.0.0-20181203042331-505ab145d0a9/go.mod h1:6SG95UA2DQfeDnf
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190820162420-60c769a6c586/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20190923035154-9ee001bba392/go.mod h1:/lpIB1dKB+9EgE3H3cr1v9wB50oz8l4C4h62xy7jSTY=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550 h1:ObdrDkeb4kJdCP557AjRjq69pTHfNouLtWZG7j9rPN8=
 golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/lint v0.0.0-20181026193005-c67002cb31c3/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
@@ -191,12 +199,15 @@ golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn
 golang.org/x/net v0.0.0-20190522155817-f3200d17e092/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190603091049-60506f45cf65/go.mod h1:HSz+uSET+XFnRR8LxR5pz3Of3rY3CfYBVs4xY44aLks=
 golang.org/x/net v0.0.0-20190613194153-d28f0bde5980/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
-golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297 h1:k7pJ2yAPLPgbskkFdhRCsA77k2fySZ1zf2zCjvQCiIM=
-golang.org/x/net v0.0.0-20190827160401-ba9fcec4b297/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20190923162816-aa69164e4478/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/net v0.0.0-20191021144547-ec77196f6094 h1:5O4U9trLjNpuhpynaDsqwCk+Tw6seqJz1EbqbnzHrc8=
+golang.org/x/net v0.0.0-20191021144547-ec77196f6094/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
 golang.org/x/oauth2 v0.0.0-20180821212333-d2e6202438be/go.mod h1:N/0e6XlmueqKjAGxoOufVs8QHGRruUQn6yWY3a++T0U=
 golang.org/x/sync v0.0.0-20180314180146-1d60e4601c6f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181108010431-42b317875d0f/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sync v0.0.0-20181221193216-37e7f081c4d4/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58 h1:8gQV6CLnAEikrhgkHFbMAEhagSSnXWGV915qUMm9mrU=
 golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20180830151530-49385e6e1522/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20180905080454-ebe1bf3edb33/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
@@ -206,9 +217,11 @@ golang.org/x/sys v0.0.0-20181205085412-a5c9d58dba9a/go.mod h1:STP8DvDyc/dI5b8T5h
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20190422165155-953cdadca894/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20190801041406-cbf593c0f2f3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20191010194322-b09406accb47 h1:/XfQ9z7ib8eEJX2hdgFTZJ/ntt0swNk5oYBziWeTCvY=
+golang.org/x/sys v0.0.0-20190922100055-0a153f010e69/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20190924154521-2837fb4f24fe/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/sys v0.0.0-20191010194322-b09406accb47/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037 h1:YyJpGZS1sBuBCzLAR1VEpK193GlqGZbnPFnPV/5Rsb4=
+golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
 golang.org/x/text v0.3.2 h1:tW2bmiBqwgJj/UpqtC8EpXEZVYOwU0yG4iWbprSVAcs=
 golang.org/x/text v0.3.2/go.mod h1:bEr9sfX3Q8Zfm5fL9x+3itogRgK3+ptLWKqgva+5dAk=
@@ -218,6 +231,8 @@ golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGm
 golang.org/x/tools v0.0.0-20190114222345-bf090417da8b/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=
 golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
 golang.org/x/tools v0.0.0-20190425163242-31fd60d6bfdc/go.mod h1:RgjU9mgBXZiqYHBnxXauZ1Gv1EHHAz9KjViQ78xBX0Q=
+golang.org/x/tools v0.0.0-20190907020128-2ca718005c18/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.6.5 h1:tycE03LOZYQNhDpS27tcQdAzLCVMaj7QT2SXxebnpCM=
 google.golang.org/appengine v1.6.5/go.mod h1:8WjMMxjGQR8xUklV/ARdw2HLXBOI7O7uCIDZVag1xfc=

logger/logger.go

@@ -54,12 +54,7 @@ func InitLogger(logFilePath string, logMaxSize int, logMaxBackups int, logMaxAge
 			MaxAge:     logMaxAge,
 			Compress:   logCompress,
 		})
-		consoleOutput := zerolog.ConsoleWriter{
-			Out:        os.Stdout,
-			TimeFormat: dateFormat,
-			NoColor:    runtime.GOOS == "windows",
-		}
-		consoleLogger = zerolog.New(consoleOutput).With().Timestamp().Logger().Level(level)
+		EnableConsoleLogger(level)
 	} else {
 		logger = zerolog.New(logSyncWrapper{
 			output: os.Stdout,
@@ -69,6 +64,22 @@ func InitLogger(logFilePath string, logMaxSize int, logMaxBackups int, logMaxAge
 	logger = logger.With().Timestamp().Logger().Level(level)
 }
 
+// DisableLogger disable the main logger.
+// ConsoleLogger will not be affected
+func DisableLogger() {
+	logger = zerolog.Nop()
+}
+
+// EnableConsoleLogger enables the console logger
+func EnableConsoleLogger(level zerolog.Level) {
+	consoleOutput := zerolog.ConsoleWriter{
+		Out:        os.Stdout,
+		TimeFormat: dateFormat,
+		NoColor:    runtime.GOOS == "windows",
+	}
+	consoleLogger = zerolog.New(consoleOutput).With().Timestamp().Logger().Level(level)
+}
+
 // Log logs at the specified level for the specified sender
 func Log(level LogLevel, sender string, connectionID string, format string, v ...interface{}) {
 	switch level {

service/service.go

@@ -5,8 +5,9 @@ import (
 	"fmt"
 	"math/rand"
 	"os"
-	"path/filepath"
+	"os/signal"
 	"strings"
+	"syscall"
 	"time"
 
 	"github.com/drakkan/sftpgo/config"
@@ -15,7 +16,7 @@ import (
 	"github.com/drakkan/sftpgo/logger"
 	"github.com/drakkan/sftpgo/sftpd"
 	"github.com/drakkan/sftpgo/utils"
-	"github.com/rs/xid"
+	"github.com/grandcat/zeroconf"
 	"github.com/rs/zerolog"
 )
 
@@ -49,6 +50,12 @@ func (s *Service) Start() error {
 		logLevel = zerolog.InfoLevel
 	}
 	logger.InitLogger(s.LogFilePath, s.LogMaxSize, s.LogMaxBackups, s.LogMaxAge, s.LogCompress, logLevel)
+	if s.PortableMode == 1 {
+		logger.EnableConsoleLogger(logLevel)
+		if len(s.LogFilePath) == 0 {
+			logger.DisableLogger()
+		}
+	}
 	version := utils.GetAppVersion()
 	logger.Info(logSender, "", "starting SFTPGo %v, config dir: %v, config file: %v, log max size: %v log max backups: %v "+
 		"log max age: %v log verbose: %v, log compress: %v", version.GetVersionAsString(), s.ConfigDir, s.ConfigFile, s.LogMaxSize,
@@ -106,11 +113,6 @@ func (s *Service) Start() error {
 			logger.DebugToConsole("HTTP server not started, disabled in config file")
 		}
 	}
-	if s.PortableMode == 1 {
-		logger.InfoToConsole("Portable mode ready, SFTP port: %v, user: %#v, password: %#v, public keys: %v, directory: %#v, permissions: %v,"+
-			" SCP enabled: %v", sftpdConf.BindPort, s.PortableUser.Username, s.PortableUser.Password, s.PortableUser.PublicKeys,
-			s.PortableUser.HomeDir, s.PortableUser.Permissions, sftpdConf.IsSCPEnabled)
-	}
 	return nil
 }
 
@@ -126,11 +128,12 @@ func (s *Service) Stop() {
 }
 
 // StartPortableMode starts the service in portable mode
-func (s *Service) StartPortableMode(sftpdPort int, enableSCP bool) error {
-	rand.Seed(time.Now().UnixNano())
+func (s *Service) StartPortableMode(sftpdPort int, enableSCP, advertiseService, advertiseCredentials bool) error {
 	if s.PortableMode != 1 {
 		return fmt.Errorf("service is not configured for portable mode")
 	}
+	var err error
+	rand.Seed(time.Now().UnixNano())
 	if len(s.PortableUser.Username) == 0 {
 		s.PortableUser.Username = "user"
 	}
@@ -141,9 +144,6 @@ func (s *Service) StartPortableMode(sftpdPort int, enableSCP bool) error {
 		}
 		s.PortableUser.Password = b.String()
 	}
-	tempDir := os.TempDir()
-	instanceID := xid.New().String()
-	s.LogFilePath = filepath.Join(tempDir, instanceID+".log")
 	dataProviderConf := config.GetProviderConf()
 	dataProviderConf.Driver = dataprovider.MemoryDataProviderName
 	config.SetProviderConf(dataProviderConf)
@@ -161,5 +161,53 @@ func (s *Service) StartPortableMode(sftpdPort int, enableSCP bool) error {
 	sftpdConf.IsSCPEnabled = enableSCP
 	config.SetSFTPDConfig(sftpdConf)
 
-	return s.Start()
+	err = s.Start()
+	if err == nil {
+		var mDNSService *zeroconf.Server
+		var err error
+		if advertiseService {
+			version := utils.GetAppVersion()
+			meta := []string{
+				fmt.Sprintf("version=%v", version.GetVersionAsString()),
+			}
+			if advertiseCredentials {
+				logger.InfoToConsole("Advertising credentials via multicast DNS")
+				meta = append(meta, fmt.Sprintf("user=%v", s.PortableUser.Username))
+				if len(s.PortableUser.Password) > 0 {
+					meta = append(meta, fmt.Sprintf("password=%v", s.PortableUser.Password))
+				} else {
+					logger.InfoToConsole("Unable to advertise key based credentials via multicast DNS, we don't have the private key")
+				}
+			}
+			mDNSService, err = zeroconf.Register(
+				fmt.Sprintf("SFTPGo portable %v", sftpdConf.BindPort), // service instance name
+				"_sftp-ssh._tcp",   // service type and protocl
+				"local.",           // service domain
+				sftpdConf.BindPort, // service port
+				meta,               // service metadata
+				nil,                // register on all network interfaces
+			)
+			if err != nil {
+				mDNSService = nil
+				logger.WarnToConsole("Unable to advertise service via multicast DNS: %v", err)
+			} else {
+				logger.InfoToConsole("Service advertised via multicast DNS")
+			}
+
+		}
+		sig := make(chan os.Signal, 1)
+		signal.Notify(sig, os.Interrupt, syscall.SIGTERM)
+		go func() {
+			<-sig
+			if mDNSService != nil {
+				logger.InfoToConsole("unregistering multicast DNS service")
+				mDNSService.Shutdown()
+			}
+			s.Stop()
+		}()
+		logger.InfoToConsole("Portable mode ready, SFTP port: %v, user: %#v, password: %#v, public keys: %v, directory: %#v, "+
+			"permissions: %v, SCP enabled: %v", sftpdConf.BindPort, s.PortableUser.Username, s.PortableUser.Password,
+			s.PortableUser.PublicKeys, s.PortableUser.HomeDir, s.PortableUser.Permissions, sftpdConf.IsSCPEnabled)
+	}
+	return err
 }