Merge pull request #35 from wizzomafizzo/custom-network

Add support for persistent Linux config files

src/downloader/constants.py

@@ -64,6 +64,15 @@
 # Linux Update files
 FILE_MiSTer_version = '/MiSTer.version'
 FILE_Linux_7z = '/media/fat/linux/7za'
+FILE_Linux_user_files = [
+    # source -> destination
+    ('/media/fat/linux/hostname', '/etc/hostname'),
+    ('/media/fat/linux/hosts', '/etc/hosts'),
+    ('/media/fat/linux/interfaces', '/etc/network/interfaces'),
+    ('/media/fat/linux/resolv.conf', '/etc/resolv.conf'),
+    ('/media/fat/linux/dhcpd.conf', '/etc/dhcpd.conf'),
+    ('/media/fat/linux/fstab', '/etc/fstab'),
+]
 
 # Reboot files
 FILE_downloader_needs_reboot_after_linux_update = '/tmp/downloader_needs_reboot_after_linux_update'

src/downloader/linux_updater.py

@@ -19,7 +19,9 @@
 import subprocess
 import json
 import sys
-from downloader.constants import FILE_downloader_needs_reboot_after_linux_update, FILE_MiSTer_version, FILE_Linux_7z
+import tempfile
+import os.path
+from downloader.constants import FILE_downloader_needs_reboot_after_linux_update, FILE_MiSTer_version, FILE_Linux_7z, FILE_Linux_user_files
 
 
 class LinuxUpdater:
@@ -29,6 +31,7 @@ def __init__(self, config, file_system, file_downloader_factory, logger):
         self._logger = logger
         self._file_system = file_system
         self._linux_descriptions = []
+        self._user_files = []
 
     def update_linux(self, importer_command):
         self._logger.bench('Update Linux start.')
@@ -68,6 +71,11 @@ def _update_linux_impl(self, importer_command):
             self._logger.debug('current_linux_version "%s" matches db linux: %s' % (current_linux_version, linux['version']))
             return
 
+        for source, destination in FILE_Linux_user_files:
+            if self._file_system.is_file(source):
+                self._logger.print('Custom "%s" file will be installed to the updated Linux system from the "linux" folder.' % (os.path.basename(source)))
+                self._user_files.append((source, destination))
+
         self._logger.print('Linux will be updated from %s:' % description['id'])
         self._logger.print('Current linux version -> %s' % current_linux_version)
         self._logger.print('Latest linux version -> %s' % linux['version'][-6:])
@@ -148,6 +156,11 @@ def _run_subprocesses(self, linux, linux_path):
             self._logger.print()
             return
 
+        if len(self._user_files) > 0:
+            restore_error = self._restore_user_files()
+            if restore_error:
+                return
+
         self._logger.print()
         self._logger.print("======================================================================================")
         self._logger.print("Hold your breath: updating the Kernel, the Linux filesystem, the bootloader and stuff.")
@@ -179,5 +192,53 @@ def _run_subprocesses(self, linux, linux_path):
             self._logger.print('Error code: %d' % result.returncode)
             self._logger.print()
 
+    def _restore_user_files(self) -> bool:
+        temp_dir = tempfile.mkdtemp()
+        self._logger.debug('Created temporary directory for image: %s' % temp_dir)
+
+        mount_cmd = 'mount -t ext4 /media/fat/linux.update/files/linux/linux.img {0}'.format(temp_dir)
+        self._logger.debug('Mounting temporary Linux image with command: %s' % mount_cmd)
+        result = subprocess.run(mount_cmd, shell=True, stderr=subprocess.STDOUT)
+
+        if result.returncode != 0:
+            self._logger.print('ERROR! Could not mount updated Linux image, try again later.')
+            self._logger.print('Error code: %d' % result.returncode)
+            self._logger.print()
+            return False
+
+        copy_error = False
+        self._logger.print('Restoring user Linux configuration files:')
+        for source, destination in self._user_files:
+            image_destination = temp_dir + destination
+            self._logger.debug('Copying "%s" to "%s"' % (source, image_destination))
+            self._logger.print(' - Installing "%s" to "%s"...' % (source, destination), end='')
+            try:
+                self._file_system.copy(source, image_destination)
+            except Exception as e:
+                self._logger.print('ERROR! Could not be installed.')
+                self._logger.debug('Could not copy "%s" to "%s": %s' % (source, destination, str(e)))
+                copy_error = True
+                break
+            else:
+                self._logger.print('OK!')
+        self._logger.print()
+
+        unmount_cmd = 'umount {0}'.format(temp_dir)
+        self._logger.debug('Unmounting Linux image with command: %s' % unmount_cmd)
+        result = subprocess.run(unmount_cmd, shell=True, stderr=subprocess.STDOUT)
+
+        if result.returncode != 0:
+            self._logger.print('ERROR! Could not unmount updated temporary Linux image.')
+            self._logger.print('Error code: %d' % result.returncode)
+            self._logger.print()
+            return False
+
+        if copy_error:
+            self._logger.print('ERROR! Could not restore user Linux configuration files.')
+            self._logger.print()
+            return False
+
+        return True
+
     def needs_reboot(self):
         return self._file_system.is_file(FILE_downloader_needs_reboot_after_linux_update)