b9c065de28
The args agument was only used to find the symbol for the getval command. Have the command pass the symbol to find in directly. We can therefore remove the args paramater to the BlockDevice() creation. Change-Id: I8e357131b70a00e4a2c4792c009f6058d1d5ae9e
344 lines
12 KiB
Python
344 lines
12 KiB
Python
# Copyright 2016-2017 Andreas Florath (andreas@florath.net)
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License"); you may
|
|
# not use this file except in compliance with the License. You may obtain
|
|
# a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
|
|
# License for the specific language governing permissions and limitations
|
|
# under the License.
|
|
|
|
import codecs
|
|
import json
|
|
import logging
|
|
import os
|
|
import shutil
|
|
import sys
|
|
import yaml
|
|
|
|
from stevedore import extension
|
|
|
|
from diskimage_builder.graph.digraph import Digraph
|
|
|
|
|
|
logger = logging.getLogger(__name__)
|
|
|
|
|
|
class BlockDeviceSetupException(Exception):
|
|
pass
|
|
|
|
|
|
class BlockDevice(object):
|
|
"""Handles block devices.
|
|
|
|
This class handles the complete setup and deletion of all aspects
|
|
of the block device level.
|
|
|
|
A typical call sequence:
|
|
|
|
cmd_init: initialize the block device level config. After this
|
|
call it is possible to e.g. query information from the (partially
|
|
automatic generated) internal state like root-label.
|
|
|
|
cmd_getval: retrieve information about the (internal) block device
|
|
state like the block image device (for bootloader) or the
|
|
root-label (for writing fstab).
|
|
|
|
cmd_create: creates all the different aspects of the block
|
|
device. When this call is successful, the complete block level
|
|
device is set up, filesystems are created and are mounted at
|
|
the correct position.
|
|
After this call it is possible to copy / install all the needed
|
|
files into the appropriate directories.
|
|
|
|
cmd_umount: unmount and detaches all directories and used many
|
|
resources. After this call the used (e.g.) images are still
|
|
available for further handling, e.g. converting from raw in
|
|
some other format.
|
|
|
|
cmd_cleanup: removes everything that was created with the
|
|
'cmd_create' call, i.e. all images files themselves and
|
|
internal temporary configuration.
|
|
|
|
cmd_delete: unmounts and removes everything that was created
|
|
during the 'cmd_create' all. This call should be used in error
|
|
conditions when there is the need to remove all allocated
|
|
resources immediately and as good as possible.
|
|
From the functional point of view this is mostly the same as a
|
|
call to 'cmd_umount' and 'cmd_cleanup' - but is typically more
|
|
error tolerance.
|
|
|
|
In a script this should be called in the following way:
|
|
|
|
dib-block-device init ...
|
|
# From that point the database can be queried, like
|
|
ROOT_LABEL=$(dib-block-device getval root-label)
|
|
|
|
Please note that currently the dib-block-device executable can
|
|
only be used outside the chroot.
|
|
|
|
dib-block-device create ...
|
|
trap "dib-block-device delete ..." EXIT
|
|
# copy / install files
|
|
dib-block-device umount ...
|
|
# convert image(s)
|
|
dib-block-device cleanup ...
|
|
trap - EXIT
|
|
"""
|
|
|
|
def _merge_into_config(self):
|
|
"""Merge old (default) config into new
|
|
|
|
There is the need to be compatible using some old environment
|
|
variables. This is done in the way, that if there is no
|
|
explicit value given, these values are inserted into the current
|
|
configuration.
|
|
"""
|
|
for entry in self.config:
|
|
for k, v in entry.items():
|
|
if k == 'mkfs':
|
|
if 'name' not in v:
|
|
continue
|
|
if v['name'] != 'mkfs_root':
|
|
continue
|
|
if 'type' not in v \
|
|
and 'root-fs-type' in self.params:
|
|
v['type'] = self.params['root-fs-type']
|
|
if 'opts' not in v \
|
|
and 'root-fs-opts' in self.params:
|
|
v['opts'] = self.params['root-fs-opts']
|
|
if 'label' not in v \
|
|
and 'root-label' in self.params:
|
|
if self.params['root-label'] is not None:
|
|
v['label'] = self.params['root-label']
|
|
else:
|
|
v['label'] = "cloudimg-rootfs"
|
|
|
|
@staticmethod
|
|
def _config_tree_to_digraph(tconfig, plugin_manager):
|
|
"""Converts a possible tree-like config into a complete digraph"""
|
|
dconfig = []
|
|
for config_entry in tconfig:
|
|
if len(config_entry) != 1:
|
|
logger.error("Invalid config entry: more than one key "
|
|
"on top level [%s]" % config_entry)
|
|
raise BlockDeviceSetupException(
|
|
"Top level config must contain exactly one key per entry")
|
|
logger.debug("Config entry [%s]" % config_entry)
|
|
config_key = list(config_entry)[0]
|
|
config_value = config_entry[config_key]
|
|
name = config_value['name'] \
|
|
if 'name' in config_value else None
|
|
if config_key not in plugin_manager:
|
|
dconfig.append(config_entry)
|
|
else:
|
|
plugin_manager[config_key].plugin \
|
|
.tree_config.config_tree_to_digraph(
|
|
config_key, config_value, dconfig, name,
|
|
plugin_manager)
|
|
return dconfig
|
|
|
|
@staticmethod
|
|
def _load_json(file_name):
|
|
if os.path.exists(file_name):
|
|
with codecs.open(file_name, encoding="utf-8", mode="r") as fd:
|
|
return json.load(fd)
|
|
return None
|
|
|
|
def __init__(self, params):
|
|
"""Create BlockDevice object
|
|
|
|
Arguments:
|
|
:param params: YAML file from --params
|
|
"""
|
|
|
|
logger.debug("Creating BlockDevice object")
|
|
|
|
self.params = params
|
|
logger.debug("Params [%s]" % self.params)
|
|
|
|
self.state_dir = os.path.join(
|
|
self.params['build-dir'], "states/block-device")
|
|
self.state_json_file_name \
|
|
= os.path.join(self.state_dir, "state.json")
|
|
self.plugin_manager = extension.ExtensionManager(
|
|
namespace='diskimage_builder.block_device.plugin',
|
|
invoke_on_load=False)
|
|
self.config_json_file_name \
|
|
= os.path.join(self.state_dir, "config.json")
|
|
|
|
self.config = self._load_json(self.config_json_file_name)
|
|
self.state = self._load_json(self.state_json_file_name)
|
|
logger.debug("Using state [%s]", self.state)
|
|
|
|
# This needs to exists for the state and config files
|
|
try:
|
|
os.makedirs(self.state_dir)
|
|
except OSError:
|
|
pass
|
|
|
|
def write_state(self, state):
|
|
logger.debug("Write state [%s]" % self.state_json_file_name)
|
|
with open(self.state_json_file_name, "w") as fd:
|
|
json.dump(state, fd)
|
|
|
|
def create_graph(self, config, default_config):
|
|
logger.debug("Create graph [%s]" % config)
|
|
# This is the directed graph of nodes: each parse method must
|
|
# add the appropriate nodes and edges.
|
|
dg = Digraph()
|
|
|
|
for config_entry in config:
|
|
if len(config_entry) != 1:
|
|
logger.error("Invalid config entry: more than one key "
|
|
"on top level [%s]" % config_entry)
|
|
raise BlockDeviceSetupException(
|
|
"Top level config must contain exactly one key per entry")
|
|
logger.debug("Config entry [%s]" % config_entry)
|
|
cfg_obj_name = list(config_entry.keys())[0]
|
|
cfg_obj_val = config_entry[cfg_obj_name]
|
|
|
|
# As the first step the configured objects are created
|
|
# (if it exists)
|
|
if cfg_obj_name not in self.plugin_manager:
|
|
logger.error("Configured top level element [%s] "
|
|
"does not exists." % cfg_obj_name)
|
|
return 1
|
|
cfg_obj = self.plugin_manager[cfg_obj_name].plugin(
|
|
cfg_obj_val, default_config)
|
|
# At this point it is only possible to add the nodes:
|
|
# adding the edges needs all nodes first.
|
|
cfg_obj.insert_nodes(dg)
|
|
|
|
# Now that all the nodes exists: add also the edges
|
|
for node in dg.get_iter_nodes_values():
|
|
node.insert_edges(dg)
|
|
|
|
call_order = dg.topological_sort()
|
|
logger.debug("Call order [%s]" % (list(call_order)))
|
|
return dg, call_order
|
|
|
|
def create(self, result, rollback):
|
|
dg, call_order = self.create_graph(self.config, self.params)
|
|
for node in call_order:
|
|
node.create(result, rollback)
|
|
|
|
def cmd_init(self):
|
|
"""Initialize block device setup
|
|
|
|
This initializes the block device setup layer. One major task
|
|
is to parse and check the configuration, write it down for
|
|
later examiniation and execution.
|
|
"""
|
|
with open(self.params['config'], "rt") as config_fd:
|
|
self.config = yaml.safe_load(config_fd)
|
|
logger.debug("Config before merge [%s]" % self.config)
|
|
self.config = self._config_tree_to_digraph(self.config,
|
|
self.plugin_manager)
|
|
logger.debug("Config before merge [%s]" % self.config)
|
|
self._merge_into_config()
|
|
logger.debug("Final config [%s]" % self.config)
|
|
# Write the final config
|
|
with open(self.config_json_file_name, "wt") as fd:
|
|
json.dump(self.config, fd)
|
|
logger.info("Wrote final block device config to [%s]"
|
|
% self.config_json_file_name)
|
|
|
|
def cmd_getval(self, symbol):
|
|
"""Retrieve value from block device level
|
|
|
|
The value of SYMBOL is printed to stdout. This is intended to
|
|
be captured into bash-variables for backward compatibility
|
|
(non python) access to internal configuration.
|
|
|
|
Arguments:
|
|
:symbol: The symbol to find
|
|
"""
|
|
logger.info("Getting value for [%s]" % symbol)
|
|
if symbol == 'image-block-partition':
|
|
# If there is no partition needed, pass back directly the
|
|
# image.
|
|
if 'root' in self.state['blockdev']:
|
|
print("%s" % self.state['blockdev']['root']['device'])
|
|
else:
|
|
print("%s" % self.state['blockdev']['image0']['device'])
|
|
return 0
|
|
if symbol == 'image-path':
|
|
print("%s" % self.state['blockdev']['image0']['image'])
|
|
return 0
|
|
logger.error("Invalid symbol [%s] for getval" % symbol)
|
|
return 1
|
|
|
|
def cmd_create(self):
|
|
"""Creates the block device"""
|
|
|
|
logger.info("create() called")
|
|
logger.debug("Using config [%s]" % self.config)
|
|
|
|
self.state = {}
|
|
rollback = []
|
|
|
|
try:
|
|
self.create(self.state, rollback)
|
|
except Exception:
|
|
logger.exception("Create failed; rollback initiated")
|
|
for rollback_cb in reversed(rollback):
|
|
rollback_cb()
|
|
sys.exit(1)
|
|
|
|
self.write_state(self.state)
|
|
|
|
logger.info("create() finished")
|
|
return 0
|
|
|
|
def cmd_umount(self):
|
|
"""Unmounts the blockdevice and cleanup resources"""
|
|
if self.state is None:
|
|
logger.info("State already cleaned - no way to do anything here")
|
|
return 0
|
|
|
|
# Deleting must be done in reverse order
|
|
dg, call_order = self.create_graph(self.config, self.params)
|
|
reverse_order = reversed(call_order)
|
|
|
|
if dg is None:
|
|
return 0
|
|
for node in reverse_order:
|
|
node.umount(self.state)
|
|
|
|
return 0
|
|
|
|
def cmd_cleanup(self):
|
|
"""Cleanup all remaining relicts - in good case"""
|
|
|
|
# Deleting must be done in reverse order
|
|
dg, call_order = self.create_graph(self.config, self.params)
|
|
reverse_order = reversed(call_order)
|
|
|
|
for node in reverse_order:
|
|
node.cleanup(self.state)
|
|
|
|
logger.info("Removing temporary dir [%s]" % self.state_dir)
|
|
shutil.rmtree(self.state_dir)
|
|
|
|
return 0
|
|
|
|
def cmd_delete(self):
|
|
"""Cleanup all remaining relicts - in case of an error"""
|
|
|
|
# Deleting must be done in reverse order
|
|
dg, call_order = self.create_graph(self.config, self.params)
|
|
reverse_order = reversed(call_order)
|
|
|
|
for node in reverse_order:
|
|
node.delete(self.state)
|
|
|
|
logger.info("Removing temporary dir [%s]" % self.state_dir)
|
|
shutil.rmtree(self.state_dir)
|
|
|
|
return 0
|