Remove old device ID from server in DeviceIDGen

core/configParser.go

@@ -2,6 +2,7 @@ package core
 
 import (
 	"fmt"
+	"io/fs"
 	"os"
 
 	"gopkg.in/ini.v1"
@@ -49,6 +50,18 @@ func ParseConfig(valuesRequested [][2]string, missingValueError string) []string
 	return config
 }
 
+// GenDeviceIDList returns a pointer to a slice of all registered device IDs.
+// Requires: errorOnFail (set to true to throw an error if the device ID list cannot be generated)
+func GenDeviceIDList(errorOnFail bool) *[]fs.DirEntry {
+	// create a slice of all registered devices
+	deviceIDList, err := os.ReadDir(ConfigDir + PathSeparator + "devices")
+	if err != nil && errorOnFail {
+		fmt.Println(AnsiError + "Failed to read the devices directory: " + err.Error() + AnsiReset)
+		os.Exit(101)
+	}
+	return &deviceIDList
+}
+
 // WriteConfig writes the provided key-value pairs under the specified section headers in the libmutton.ini file.
 // Requires: valuesToWrite (a slice of length 3 arrays each containing a section, a key name, and a value).
 func WriteConfig(valuesToWrite [][3]string, append bool) {

core/init.go

@@ -53,7 +53,8 @@ func GpgKeyGen() string {
 }
 
 // DirInit creates the libmutton directories.
-func DirInit(preserveOldConfigDir bool) {
+// Returns: oldDeviceID (before from before the directory reset).
+func DirInit(preserveOldConfigDir bool) string {
 	// create EntryRoot
 	err := os.MkdirAll(EntryRoot, 0700)
 	if err != nil {
@@ -61,6 +62,9 @@ func DirInit(preserveOldConfigDir bool) {
 		os.Exit(102)
 	}
 
+	// get old device ID before its potential removal
+	oldDeviceID := (*GenDeviceIDList(false))[0].Name() // errorOnFail set to false to ignore error if device ID directory does not exist (error non-critical for this function)
+
 	// remove existing config directory (if it exists and not in append mode)
 	if !preserveOldConfigDir {
 		_, isAccessible := TargetIsFile(ConfigDir, false, 1)
@@ -79,4 +83,6 @@ func DirInit(preserveOldConfigDir bool) {
 		fmt.Println(AnsiError + "Failed to create \"" + ConfigDir + "\": " + err.Error() + AnsiReset)
 		os.Exit(102)
 	}
+
+	return oldDeviceID
 }

libmuttonserver.go

@@ -56,7 +56,9 @@ func main() {
 	case "register":
 		// register a new device ID
 		// stdin[0] is expected to be the device ID
-		_, _ = os.Create(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + stdin[0]) // error ignored; failure unlikely to occur if init was successful; "register" is not a user-facing argument and thus the error would not be visible
+		// stdin[1] is expected to be the old device ID (for removal)
+		_, _ = os.Create(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + stdin[0]) // errors ignored; failure unlikely to occur if init was successful; "register" is not a user-facing argument and thus the error would not be visible
+		_ = os.RemoveAll(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + stdin[1])
 		// print EntryRoot and bool indicating OS type to stdout for client to store in config
 		fmt.Print(core.EntryRoot + sync.FSSpace + strconv.FormatBool(core.IsWindows))
 	case "init":

sync/client.go

@@ -129,8 +129,8 @@ func GetSSHOutput(sshClient *ssh.Client, cmd, stdin string) string {
 // getRemoteDataFromClient returns a map of remote entries to their modification times, a list of remote folders, a list of queued deletions, and the current server&client times as UNIX timestamps.
 func getRemoteDataFromClient(sshClient *ssh.Client, manualSync bool) (map[string]int64, []string, []string, int64, int64) {
 	// get remote output over SSH
-	clientDeviceID, _ := os.ReadDir(core.ConfigDir + core.PathSeparator + "devices")
-	if len(clientDeviceID) == 0 {
+	deviceIDList := core.GenDeviceIDList(true)
+	if len(*deviceIDList) == 0 {
 		if manualSync {
 			fmt.Println(joinErrorWithEXE("Sync failed - No device ID found; run \"", " init\" to generate a device ID"))
 			os.Exit(105)
@@ -139,7 +139,7 @@ func getRemoteDataFromClient(sshClient *ssh.Client, manualSync bool) (map[string
 		}
 	}
 	clientTime := time.Now().Unix() // get client time now to avoid accuracy issues caused by unpredictable sync time
-	output := GetSSHOutput(sshClient, "libmuttonserver fetch", clientDeviceID[0].Name())
+	output := GetSSHOutput(sshClient, "libmuttonserver fetch", (*deviceIDList)[0].Name())
 
 	// split output into slice based on occurrences of FSSpace
 	outputSlice := strings.Split(output, FSSpace)
@@ -409,7 +409,7 @@ func ShearRemoteFromClient(sshClient *ssh.Client, targetLocationIncomplete strin
 func RenameRemoteFromClient(sshClient *ssh.Client, oldLocationIncomplete, newLocationIncomplete string) {
 	RenameLocal(oldLocationIncomplete, newLocationIncomplete, false) // move the target on the local system
 
-	deviceIDList := genDeviceIDList()
+	deviceIDList := core.GenDeviceIDList(true)
 	if len(*deviceIDList) > 0 { // ensure a device ID exists (online mode)
 		// call the server to move the target on the remote system and add the old target to the deletions list
 		GetSSHOutput(sshClient, "libmuttonserver rename",

sync/common.go

@@ -2,7 +2,6 @@ package sync
 
 import (
 	"fmt"
-	"io/fs"
 	"os"
 	"strings"
 
@@ -20,17 +19,6 @@ func getModTimes(entryList []string) []int64 {
 	return modList
 }
 
-// genDeviceIDList returns a pointer to a slice of all registered device IDs.
-func genDeviceIDList() *[]fs.DirEntry {
-	// create a slice of all registered devices
-	deviceIDList, err := os.ReadDir(core.ConfigDir + core.PathSeparator + "devices")
-	if err != nil {
-		fmt.Println(core.AnsiError + "Failed to read the devices directory: " + err.Error() + core.AnsiReset)
-		os.Exit(101)
-	}
-	return &deviceIDList
-}
-
 // ShearLocal removes the target file or directory from the local system.
 // Returns: deviceID (only on client; for use in ShearRemoteFromClient).
 // If the local system is a server, it will also add the target to the deletions list for all clients (except the requesting client).
@@ -42,7 +30,7 @@ func ShearLocal(targetLocationIncomplete, clientDeviceID string) string {
 		onServer = true
 	}
 
-	deviceIDList := genDeviceIDList()
+	deviceIDList := core.GenDeviceIDList(true)
 
 	// add the sheared target (incomplete, vanity) to the deletions list (if running on a server)
 	if onServer {

sync/init.go

@@ -9,25 +9,38 @@ import (
 	"time"
 
 	"github.com/rwinkhart/libmutton/core"
+	"golang.org/x/crypto/ssh"
 )
 
-// DeviceIDGen generates a new client device ID and registers it with the server.
+// DeviceIDGen generates a new client device ID and registers it with the server (will replace existing one).
 // Device IDs are only needed for online synchronization.
 // Device IDs are guaranteed unique as the current UNIX time is appended to them.
 // Returns: the remote EntryRoot and OS type indicator.
-func DeviceIDGen() (string, string) {
+func DeviceIDGen(oldDeviceID string) (string, string) {
+	// generate new device ID
 	deviceIDPrefix, _ := os.Hostname()
 	deviceIDSuffix := core.StringGen(rand.Intn(32)+48, true, 0.2, true) + "-" + strconv.FormatInt(time.Now().Unix(), 10)
-	deviceID := deviceIDPrefix + "-" + deviceIDSuffix
-	_, err := os.Create(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + deviceID) // TODO remove existing device ID file if it exists (from both client and server)
+	newDeviceID := deviceIDPrefix + "-" + deviceIDSuffix
+
+	// create new device ID file (locally)
+	_, err := os.Create(core.ConfigDir + core.PathSeparator + "devices" + core.PathSeparator + newDeviceID) // TODO remove existing device ID file if it exists (from both client and server)
 	if err != nil {
 		fmt.Println(core.AnsiError + "Failed to create local device ID file: " + err.Error() + core.AnsiReset)
+		os.Exit(102)
 	}
 
-	// register device ID with server and fetch remote EntryRoot and OS type
+	// register new device ID with server and fetch remote EntryRoot and OS type
+	// also removes the old device ID file (remotely)
 	// manualSync is true so the user is alerted if device ID registration fails
 	sshClient, _, _ := GetSSHClient(true)
-	sshEntryRootSSHIsWindows := strings.Split(GetSSHOutput(sshClient, "libmuttonserver register", deviceID), FSSpace)
+	defer func(sshClient *ssh.Client) {
+		err = sshClient.Close()
+		if err != nil {
+			fmt.Println(core.AnsiError + "Init failed - Unable to close SSH client: " + err.Error() + core.AnsiReset)
+			os.Exit(104)
+		}
+	}(sshClient)
+	sshEntryRootSSHIsWindows := strings.Split(GetSSHOutput(sshClient, "libmuttonserver register", newDeviceID+"\n"+oldDeviceID), FSSpace)
 
 	return sshEntryRootSSHIsWindows[0], sshEntryRootSSHIsWindows[1]
 }