Add support for backing up and restoring software

scripts/Arch/OS/backup.fish

@@ -0,0 +1,15 @@
+#!/bin/env fish
+begin
+    set -l dir (status dirname)
+
+    function installValhallaDeps -V dir
+        source "$dir/../lib/software.fish"
+        and pacinst fish git jq nix sudo tmux
+    end
+
+    function getDeploymentScript -V dir
+        echo "$dir/../lib/deploy.fish"
+    end
+
+    source "$dir/../../Common/OS/backup.fish"
+end

scripts/Common/OS/backup.fish

@@ -0,0 +1,60 @@
+#!/bin/env fish
+set -l dir (status dirname)
+source "$dir/../../lib/action.fish"
+
+function backupAction -V dir
+    source "$dir/../../lib/hooks.fish"
+
+    if not type -q getDeploymentScript
+        function getDeploymentScript
+            echo "No deployment script specified! No software will be installed." 1>&2
+            false
+        end
+    end
+
+    set -l deployScript (getDeploymentScript)
+
+    if fish "$dir/../../../lib/modules/partition/confirm.fish" "Do you wish to store the backup on an SSH server?" n
+        read -xP "Please specify the host name of the SSH server: " VALHALLA_BACKUP_SERVER
+        read -xP "Please specify the port of the SSH server (default 22): " VALHALLA_BACKUP_SERVER_PORT
+        read -xP "Please specify the name of the user to log in to the SSH server: " VALHALLA_BACKUP_SERVER_USER
+
+        if [ -z "$VALHALLA_BACKUP_SERVER_PORT" ]
+            set -x VALHALLA_BACKUP_SERVER_PORT 22
+        end
+
+        if [ -n "$VALHALLA_BACKUP_USER" ]
+            set -x VALHALLA_BACKUP_SERVER "$VALHALLA_BACKUP_SERVER_USER@$VALHALLA_BACKUP_SERVER"
+        end
+
+        echo
+        echo "$(tput setaf 3)==== WARNING ====$(tput sgr0)"
+        echo "For a seamless experience, please make sure that you are able to establish an unattended ssh connection using key authentication."
+        echo
+        echo "$(tput bold)This command should succeed without user interaction:$(tput sgr0)"
+        echo "ssh -o PasswordAuthentication=no -p $VALHALLA_BACKUP_SERVER_PORT $VALHALLA_BACKUP_SERVER true"
+        read -P "Press enter once you're done: "
+        echo
+    end
+
+    read -xP "Please specify the path to the directory to save the backup to: " VALHALLA_BACKUP_DIR
+
+    runHook backupSoftware || begin
+        echo "Backing up software..."
+
+        and if [ -n "$deployScript" ]
+            source $deployScript backup
+        end
+    end
+
+    runHook backupUsers || begin
+        if [ -n "$deployScript" ]
+            for name in (getUsers | jq '.[]' --raw-output0 | string split0)
+                echo "Backing up user `$name`..."
+                and source $deployScript userBackup $name
+            end
+        end
+    end
+end
+
+runSetupUserAction backupAction

scripts/lib/restoration.fish

@@ -0,0 +1,81 @@
+function backupFiles
+    if [ -n "$VALHALLA_BACKUP_DIR" ]
+        argparse -i "base-directory=" -- $argv
+        set -l tarArgs
+        set -l path (getArchivePath $argv)
+        set -l dir (dirname "$path")
+        argparse -i "u/user=" "n/name=" -- $argv
+    
+        if runRestorationCommand test ! -d "$dir"
+            runRestorationCommand mkdir -p "$dir"
+        end
+    
+        if [ -n "$_flag_base_directory" ]
+            set -a argv --base-directory "$_flag_base_directory"
+            set -a tarArgs -C "$_flag_base_directory"
+        else
+            set -a tarArgs -P
+        end
+    
+        sudo tar $tarArgs -cvz (fd $argv) | createArchive "$path"
+    end
+end
+
+function restoreFiles
+    if [ -n "$VALHALLA_BACKUP_DIR" ]
+        argparse -i "user=" "base-directory=" -- $argv
+        set -l tarArgs
+        set -l sudoArgs
+
+        if [ -n "$_flag_base_directory" ]
+            set -a tarArgs -C "$_flag_base_directory"
+        else
+            set -a tarArgs -P
+        end
+
+        if [ -n "$_flag_user" ]
+            set -a sudoArgs -u "$_flag_user"
+        end
+
+        fetchArchive $argv | begin
+            sudo $sudoArgs tar $tarArgs -xvz
+        end
+    end
+end
+
+function createArchive -a path
+    runRestorationCommand tee "$path" \>/dev/null
+end
+
+function fetchArchive
+    set -l path (getArchivePath $argv)
+    runRestorationCommand cat "$path"
+end
+
+function runRestorationCommand
+    if [ -z "$VALHALLA_BACKUP_SERVER" ]
+        $argv
+    else
+        set -l args
+
+        if [ -n "$VALHALLA_BACKUP_SERVER_PORT" ]
+            set -a args -p $VALHALLA_BACKUP_SERVER_PORT
+        end
+
+        ssh $args "$VALHALLA_BACKUP_SERVER" (string escape -- $argv)
+    end
+end
+
+function getArchivePath
+    argparse -i "u/user=" "n/name=" -- $argv
+    set -l path "$VALHALLA_BACKUP_DIR"
+
+    if [ -b "$_flag_user" ]
+        set -a path Users "$_flag_user"
+    else
+        set -a path System
+    end
+
+    set -a path "$_flag_name.tar.gz"
+    realpath -m (string join / $path)
+end

scripts/lib/software.fish

@@ -2,15 +2,62 @@
 begin
     set -l dir (status dirname)
 
+    set -l backupActions \
+        backup backupSW backupArgs getBackupArgs restore restoreSW \
+        userBackup userBackup userBackupArgs getUserBackupArgs userRestore userRestore
+
     set -l actions \
         install installSW \
         configure configureSW \
         userConfig userConfig
 
+    set -a actions $backupActions
+
     for i in (seq 2 2 (count $actions))
         functions -e "$actions[$i]"
     end
 
+    for i in (seq 1 6 (count $backupActions))
+        set -l function $backupActions[(math $i + 1)]
+        set -l getArgs $backupActions[(math $i + 3)]
+        set -l restore $backupActions[(math $i + 5)]
+
+        for functionName in $function $restore
+            function $functionName -V dir -V getArgs -V functionName -V restore
+                set -l args
+
+                if functions -q $getArgs
+                    set args ($getArgs $argv)
+                end
+
+                if [ "$functionName" = "$restore" ] || [ -n "$args" ]
+                    for arg in name user
+                        set -l varName "_flag_$arg"
+
+                        begin
+                            set -l backup $argv
+                            argparse -i "$arg=" -- $args
+                            set -l argv $backup
+                        end
+    
+                        if [ -z "$$varName" ]
+                            argparse -i "$arg=" -- $argv
+                            set -a args "--$arg" "$$varName"
+                        end
+                    end
+
+                    source "$dir/restoration.fish"
+
+                    if [ "$functionName" != "$restore" ]
+                        backupFiles $args
+                    else
+                        restoreFiles $args
+                    end
+                end
+            end
+        end
+    end
+
     function runPSUserAction
         argparse -i "script=" "action=" "user=" -- $argv
 
@@ -86,7 +133,9 @@ begin
             if [ "$action" = "$actions[$i]" ]
                 set -l message
                 set -l function $actions[(math $i + 1)]
+                set -l preRun "__preRun"
                 set -l postRun "__postRun"
+                functions -e $preRun
                 functions -e $postRun
 
                 switch "$action"
@@ -102,7 +151,11 @@ begin
                         end
                     case configure
                         set message "Configuring `$name`..."
-                    case userConfig
+
+                        function $preRun -V args
+                            runInstallerAction $args --action restore
+                        end
+                    case userConfig userBackup userRestore
                         argparse -i "user=" -- $argv
                         set -l user "$_flag_user"
 
@@ -117,7 +170,22 @@ begin
                             set install false
                         end
 
-                        set message "Configuring `$name` for `$user`..."
+                        switch "$action"
+                            case userConfig
+                                set message "Configuring `$name` for `$user`..."
+
+                                function $preRun -V args
+                                    runInstallerAction $args --action userRestore
+                                end
+                            case userBackup
+                                set message "Backing up `$name` for `$user`..."
+                            case userRestore
+                                set message "Restoring `$name` for `$user`..."
+                        end
+                end
+
+                if functions -q $preRun
+                    $preRun
                 end
 
                 if functions -q "$function" && $install