Introduce experimental live mode [squashfs]

etc/leapp/files/devel-livemode.ini

@@ -0,0 +1,9 @@
+# Configuration for the *experimental* livemode feature
+# It is likely that this entire configuration file will be replaced by some
+# other mechanism/file in the future. For the full list of configuration options,
+# see models/livemode.py
+[livemode]
+squashfs_fullpath=/var/lib/leapp/live-upgrade.img
+setup_network_manager=no
+autostart_upgrade_after_reboot=yes
+setup_passwordless_root=no

repos/system_upgrade/common/actors/addupgradebootentry/actor.py

@@ -3,7 +3,17 @@
 from leapp.actors import Actor
 from leapp.exceptions import StopActorExecutionError
 from leapp.libraries.actor.addupgradebootentry import add_boot_entry, fix_grub_config_error
-from leapp.models import BootContent, FirmwareFacts, GrubConfigError, TargetKernelCmdlineArgTasks, TransactionDryRun
+from leapp.models import (
+    BootContent,
+    FirmwareFacts,
+    GrubConfigError,
+    KernelCmdline,
+    LiveImagePreparationInfo,
+    LiveModeArtifacts,
+    LiveModeConfig,
+    TargetKernelCmdlineArgTasks,
+    TransactionDryRun
+)
 from leapp.tags import InterimPreparationPhaseTag, IPUWorkflowTag
 
 
@@ -15,7 +25,16 @@ class AddUpgradeBootEntry(Actor):
     """
 
     name = 'add_upgrade_boot_entry'
-    consumes = (BootContent, GrubConfigError, FirmwareFacts, TransactionDryRun)
+    consumes = (
+        BootContent,
+        GrubConfigError,
+        FirmwareFacts,
+        LiveImagePreparationInfo,
+        LiveModeArtifacts,
+        LiveModeConfig,
+        KernelCmdline,
+        TransactionDryRun
+    )
     produces = (TargetKernelCmdlineArgTasks,)
     tags = (IPUWorkflowTag, InterimPreparationPhaseTag)
 

repos/system_upgrade/common/actors/addupgradebootentry/libraries/addupgradebootentry.py

@@ -1,41 +1,152 @@
+import itertools
 import os
 import re
 
 from leapp.exceptions import StopActorExecutionError
-from leapp.libraries.common.config import architecture
+from leapp.libraries.common.config import architecture, get_env
 from leapp.libraries.stdlib import api, CalledProcessError, run
-from leapp.models import BootContent, KernelCmdlineArg, TargetKernelCmdlineArgTasks
+from leapp.models import (
+    BootContent,
+    KernelCmdline,
+    KernelCmdlineArg,
+    LiveImagePreparationInfo,
+    LiveModeArtifacts,
+    LiveModeConfig,
+    TargetKernelCmdlineArgTasks
+)
+
+
+def collect_boot_args(livemode_enabled):
+    args = {
+        'enforcing': '0',
+        'rd.plymouth': '0',
+        'plymouth.enable': '0'
+    }
+
+    if get_env('LEAPP_DEBUG', '0') == '1':
+        args['debug'] = None
+
+    if get_env('LEAPP_DEVEL_INITRAM_NETWORK') in ('network-manager', 'scripts'):
+        args['ip'] = 'dhcp'
+        args['rd.neednet'] = '1'
+
+    if livemode_enabled:
+        livemode_args = construct_cmdline_args_for_livemode()
+        args.update(livemode_args)
+
+    return args
+
+
+def collect_undesired_args(livemode_enabled):
+    args = {}
+    if livemode_enabled:
+        args = dict(zip(('ro', 'rhgb', 'quiet'), itertools.repeat(None)))
+        args['rd.lvm.lv'] = _get_rdlvm_arg_values()
+
+    return args
+
+
+def format_grubby_args_from_args_dict(args_dict):
+    """ Format the given args dictionary in a form required by grubby's --args. """
+
+    def fmt_single_arg(arg_pair):
+        key, value = arg_pair
+        if not value:
+            return str(key)
+        return '{key}={value}'.format(key=key, value=value)
+
+    def flatten_arguments(arg_pair):
+        """ Expand multi-valued values into an iterable (key, value1), (key, value2) """
+        key, value = arg_pair
+        if isinstance(value, (tuple, list)):
+            # value is multi-valued (a tuple of values)
+            for value_elem in value:  # yield from is not available in python2.7
+                yield (key, value_elem)
+        else:
+            yield (key, value)  # Just a single (key, value) pair
+
+    arg_sequence = itertools.chain(*(flatten_arguments(arg_pair) for arg_pair in args_dict.items()))
+
+    # Sorting should be fine as only values can be None, but we cannot have a (key, None) and (key, value) in
+    # the dictionary at the same time.
+    cmdline_pieces = (fmt_single_arg(arg_pair) for arg_pair in sorted(arg_sequence))
+    cmdline = ' '.join(cmdline_pieces)
+
+    return cmdline
+
+
+def figure_out_commands_needed_to_add_entry(kernel_path, initramfs_path, args_to_add, args_to_remove):
+    boot_entry_modification_commands = []
+
+    args_to_add_str = format_grubby_args_from_args_dict(args_to_add)
+
+    create_entry_cmd = [
+        '/usr/sbin/grubby',
+        '--add-kernel', '{0}'.format(kernel_path),
+        '--initrd', '{0}'.format(initramfs_path),
+        '--title', 'RHEL-Upgrade-Initramfs',
+        '--copy-default',
+        '--make-default',
+        '--args', args_to_add_str
+    ]
+    boot_entry_modification_commands.append(create_entry_cmd)
+
+    # We need to update root= param separately, since we cannot do it during --add-kernel with --copy-default.
+    # This is likely a bug in grubby.
+    root_param_value = args_to_add.get('root', None)
+    if root_param_value:
+        enforce_root_param_for_the_entry_cmd = [
+            '/usr/sbin/grubby',
+            '--update-kernel', kernel_path,
+            '--args', 'root={0}'.format(root_param_value)
+        ]
+        boot_entry_modification_commands.append(enforce_root_param_for_the_entry_cmd)
+
+    if args_to_remove:
+        args_to_remove_str = format_grubby_args_from_args_dict(args_to_remove)
+        remove_undesired_args_cmd = [
+            '/usr/sbin/grubby',
+            '--update-kernel', kernel_path,
+            '--remove-args', args_to_remove_str
+        ]
+        boot_entry_modification_commands.append(remove_undesired_args_cmd)
+    return boot_entry_modification_commands
 
 
 def add_boot_entry(configs=None):
-    debug = 'debug' if os.getenv('LEAPP_DEBUG', '0') == '1' else ''
-    enable_network = os.getenv('LEAPP_DEVEL_INITRAM_NETWORK') in ('network-manager', 'scripts')
-    ip_arg = ' ip=dhcp rd.neednet=1' if enable_network else ''
     kernel_dst_path, initram_dst_path = get_boot_file_paths()
     _remove_old_upgrade_boot_entry(kernel_dst_path, configs=configs)
+
+    livemode_enabled = next(api.consume(LiveImagePreparationInfo), None) is not None
+
+    cmdline_args = collect_boot_args(livemode_enabled)
+    undesired_cmdline_args = collect_undesired_args(livemode_enabled)
+
+    commands_to_run = figure_out_commands_needed_to_add_entry(kernel_dst_path,
+                                                              initram_dst_path,
+                                                              args_to_add=cmdline_args,
+                                                              args_to_remove=undesired_cmdline_args)
+
+    def run_commands_adding_entry(extra_command_suffix=None):
+        if not extra_command_suffix:
+            extra_command_suffix = []
+        for command in commands_to_run:
+            run(command + extra_command_suffix)
+
     try:
-        cmd = [
-            '/usr/sbin/grubby',
-            '--add-kernel', '{0}'.format(kernel_dst_path),
-            '--initrd', '{0}'.format(initram_dst_path),
-            '--title', 'RHEL-Upgrade-Initramfs',
-            '--copy-default',
-            '--make-default',
-            '--args', '{DEBUG}{NET} enforcing=0 rd.plymouth=0 plymouth.enable=0'.format(DEBUG=debug, NET=ip_arg)
-        ]
         if configs:
             for config in configs:
-                run(cmd + ['-c', config])
+                run_commands_adding_entry(extra_command_suffix=['-c', config])
         else:
-            run(cmd)
+            run_commands_adding_entry(extra_command_suffix=None)
 
         if architecture.matches_architecture(architecture.ARCH_S390X):
             # on s390x we need to call zipl explicitly because of issue in grubby,
             # otherwise the new boot entry will not be set as default
             # See https://bugzilla.redhat.com/show_bug.cgi?id=1764306
             run(['/usr/sbin/zipl'])
 
-        if debug:
+        if 'debug' in cmdline_args:
             # The kernelopts for target kernel are generated based on the cmdline used in the upgrade initramfs,
             # therefore, if we enabled debug above, and the original system did not have the debug kernelopt, we
             # need to explicitly remove it from the target os boot entry.
@@ -114,3 +225,101 @@ def fix_grub_config_error(conf_file, error_type):
 
     elif error_type == 'missing newline':
         write_to_file(conf_file, config + '\n')
+
+
+def local_os_stat(path):
+    """ Local wrapper around os.stat so we can safely mock it in tests. """
+    return os.stat(path)
+
+
+def _get_device_uuid(path):
+    """
+    Find the UUID of a device in which the given path is located.
+    """
+    while not os.path.ismount(path):
+        path = os.path.dirname(path)
+
+    needle_dev_id = local_os_stat(path).st_dev
+
+    for uuid in os.listdir('/dev/disk/by-uuid'):
+        uuid_fullpath = os.path.join('/dev/disk/by-uuid/', uuid)
+        dev_path = os.readlink(uuid_fullpath)
+
+        # The link target is likely relative to the UUID_fullpath, e.g., ../../dm-1.
+        # Joining it will '/dev/disk/by-uuid' will resolve the relative path.
+        # If dev_path is absolute it returns dev_path.
+        dev_path = os.path.join('/dev/disk/by-uuid', dev_path)
+        dev_path = os.path.abspath(dev_path)
+
+        dev_id = local_os_stat(dev_path).st_rdev
+        if dev_id == needle_dev_id:
+            return uuid
+
+    return None
+
+
+def _get_rdlvm_arg_values():
+    # should we not check args returned by grubby instead?
+    cmdline_msg = next(api.consume(KernelCmdline), None)
+
+    if not cmdline_msg:
+        raise StopActorExecutionError('Did not receive any KernelCmdline arguments.')
+
+    rd_lvm_values = sorted(arg.value for arg in cmdline_msg.parameters if arg.key == 'rd.lvm.lv')
+    api.current_logger().debug('Collected the following rd.lvm.lv args that are undesired for the squashfs: %s',
+                               rd_lvm_values)
+
+    return rd_lvm_values
+
+
+def construct_cmdline_args_for_livemode():
+    """
+    Prepare cmdline parameters for the live mode
+    """
+    # boot locally by default
+
+    livemode_config = next(api.consume(LiveModeConfig), None)
+    if not livemode_config:
+        raise StopActorExecutionError('Did not receive any livemode configuration message although it is enabled.')
+
+    livemode_artifacts = next(api.consume(LiveModeArtifacts), None)
+    if not livemode_artifacts:
+        raise StopActorExecutionError('Did not receive any livemode artifacts message although it is enabled.')
+
+    liveimg_filename = os.path.basename(livemode_artifacts.squashfs_path)
+    dir_path_containing_liveimg = os.path.dirname(livemode_artifacts.squashfs_path)
+
+    args = {'rw': None}
+
+    # if an URL is defined, boot over the network (http, nfs, ftp, ...)
+    if livemode_config.url_to_load_squashfs_from:
+        args['root'] = 'live:{}'.format(livemode_config.url_to_load_squashfs_from)
+    else:
+        args['root'] = 'live:UUID={}'.format(_get_device_uuid(dir_path_containing_liveimg))
+        args['rd.live.dir'] = dir_path_containing_liveimg
+        args['rd.live.squashimg'] = liveimg_filename
+
+    if livemode_config.dracut_network:
+        network_fragments = livemode_config.dracut_network.split('=', 1)
+
+        # @Todo(mhecko): verify this during config scan
+        if len(network_fragments) == 1 or network_fragments[0] != 'ip':
+            msg = ('The livemode dracut_network configuration value is incorrect - it does not '
+                   'have the form of a key=value cmdline arg: `{0}`.')
+            msg = msg.format(livemode_config.dracut_network)
+
+            api.current_logger().error(msg)
+            raise StopActorExecutionError('Livemode is not configured correctly.', details={'details': msg})
+
+        args['ip'] = network_fragments[1]
+        args['rd.needsnet'] = '1'
+
+    autostart_state = '1' if livemode_config.autostart_upgrade_after_reboot else '0'
+    args['upgrade.autostart'] = autostart_state
+
+    if livemode_config.capture_upgrade_strace_into:
+        args['upgrade.strace'] = livemode_config.capture_upgrade_strace_into
+
+    api.current_logger().info('The use of live mode image implies the following cmdline args: %s', args)
+
+    return args