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34 commits

Author SHA1 Message Date
Ian Wienand
6c394f5746 Pass all blockdevices to bootloader
Currently we only export "image-block-device" which is the loopback
device (/dev/loopX) for the underlying image.  This is the device we
install grub to (from inside the chroot ...)

This is ok for x86, but is insufficient for some platforms like PPC
which have a separate boot partition.  They do not want to install to
the loop device, but do things like dd special ELF files into special
boot partitions.

The first problem seems to be that in level1/partitioning.py we have a
whole bunch of different paths that either call partprobe on the loop
device, or kpartx.  We have _all_part_devices_exist() that gates the
kpartx for unknown reasons.  We have detach_loopback() that does not
seem to remove losetup created devices.  I don't think this does
cleanup if it uses kpartx correctly.  It is extremley unclear what's
going to be mapped where.

This moves to us *only* using kpartx to map the partitions of the loop
device.  We will *not* call partprobe and create the /dev/loopXpN
devices and will only have the devicemapper nodes kpartx creates.
This seems to be best.  Cleanup happens inside partitioning.py.
practice.  Deeper thinking about this, and more cleanup of the
variables will be welcome.

This adds "image-block-devices" (note the extra "s") which exports all
the block devices with name and path.  This is in a string format that
can be eval'd to an array (you can't export arrays).

This is then used in a follow-on
(I0918e8df8797d6dbabf7af618989ab7f79ee9580) to pick the right
partition on PPC.

Change-Id: If8e33106b4104da2d56d7941ce96ffcb014907bc
2017-06-08 17:14:22 +10:00
Ian Wienand
1d1e4ccb3e Move rollback into NodeBase object
Currently we pass a reference to a global "rollback" list to create()
to keep rollback functions.  Other nodes don't need to know about
global rollback state, and by passing by reference we're giving them
the chance to mess it up for everyone else.

Add a "add_rollback()" function in NodeBase for create() calls to
register rollback calls within themselves.  As they hit rollback
points they can add a new entry.  lambda v arguments is much of a
muchness -- but this is similar to the standard atexit() call so with
go with that pattern.  A new "rollback()" call is added that the
driver will invoke on each node as it works its way backwards in case
of failure.

On error, nodes will have rollback() called in reverse order (which
then calls registered rollbacks in reverse order).

A unit test is added to test rollback behaviour

Change-Id: I65214e72c7ef607dd08f750a6d32a0b10fe97ac3
2017-06-08 17:14:20 +10:00
Ian Wienand
b708918b85 Remove 'state' argument from later cmd_* calls
With I468dbf5134947629f125504513703d6f2cdace59 each node has a
reference to the global state object.  This means it gets pickled into
the node-list, which is loaded for later calls.  There is no need to
reload the state.json it and pass it for later cmd_* calls, as the
nodes can see it via the unpickled self.state

Change-Id: I9e2f8910f17599d92ee33e7df8e36d8ed4d44575
2017-06-08 17:13:28 +10:00
Ian Wienand
824a9e91c4 Add state to NodeBase class
Making the global state reference a defined part of the node makes
some parts of the block device processing easier and removes the need
for other global values.

The state is passed to PluginNodeBase.__init__() and expected to be
passed into all nodes as they are created.  NodeBase.__init__() is
updated with the new paramater 'state'.

The parameter is removed from the create() call as nodes can simply
reference it at any point as "self.state".

This is similar to 1cdc8b20373c5d582ea928cfd7334469ff36dbce, except it
is based on I68840594a34af28d41d9522addcfd830bd203b97 which loads the
node-list from pickled state for later cmd_* calls.  Thus we only
build the state *once*, at cmd_create() time as we build the node
list.

Change-Id: I468dbf5134947629f125504513703d6f2cdace59
2017-06-08 17:13:26 +10:00
Ian Wienand
e82e0097a9 Use picked nodes for later cmd_* calls
Currently the later cmd_* calls -- umount, cleanup, delete -- all
recreate the node graph by parsing the config file using
create_graph()

There is some need, however, to have a sense of global state when
building the node list.  The problem is, this is a one time operation
-- we do not want to rebuild that state for these later calls (see the
"loaded" checks in proposed
Ic3b805f9258128d5233b21ff25579c03487c7fcc).

An insight here seems to be that these cmd_* calls do not actually
want to re-parse the configuration file and rebuild the node list;
they just want to walk the node list in reverse with the state as
provided after cmd_create().

So, rather than re-creating the node list, we might as well just
pickle it, save it to disk along side the state dictionary dump and
reload it for cmd_*.

After this, I think we can safely have PluginBase.__init__() be passed
the state.  We will now know that this will only be called once,
during initial creation.

Change-Id: I68840594a34af28d41d9522addcfd830bd203b97
2017-06-08 17:10:10 +10:00
Ian Wienand
7661da1341 Pad state dump
Because we append the function/line info after debug lines in the gate
logs, the pretty-print ends up not looking all that pretty.  Pad it.

Change-Id: Ice013428342614300cd51e8b7be56e79b75b31fc
2017-06-06 12:34:00 +10:00
Ian Wienand
4253cab773 Make BlockDeviceState implement a dict
While plugins treat the state as just a dictionary, it's nice for the
driver functions to keep state related functions encapsulated in the
state object singleton.  Wrap the internal state dictionary so we can
pass the BlockDeviceState directly without dereferencing.

Change-Id: Ic0193c64d645ed1312f898cbfef87841f460799c
2017-05-31 11:24:55 +10:00
Ian Wienand
b85de3cd9e Add state object, rename "results", add unit tests
A couple of things going on, but I think it makes sense to do them
atomically.

The NodeBase.create() argument "results" is the global state
dictionary that will be saved to "state.json", and re-loaded in later
phases and passed to them as the argument "state".  So for
consistency, call this argument "state" (this fits with the change out
to start building the state dictionary earlier in the
PluginBase.__init__() calls).

Since the "state" is a pretty important part of how everything works,
move it into a separate object.  This is treated as essentially a
singleton.  It bundles it nicely together for some added
documentation [1].

We move instantiation of this object out of the generic
BlockDevice.__init__() call and into the actual cmd_* drivers.  This
is because there's two distinct instantiation operations -- creating a
new state (during cmd_create) and loading an existing state (other
cmd_*).  This is also safer -- since we know the cmd_* arguments are
looking for an existing state.json, we will fail if it somehow goes
missing.

To more fully unit test this, some testing plugins and new
entry-points are added.  These add known state values which we check
for.  These should be a good basis for further tests.

[1] as noted, we could probably do some fun things in the future like
make this implement a dictionary and have some saftey features like
r/o keys.

Change-Id: I90eb711b3e9b1ce139eb34bdf3cde641fd06828f
2017-05-30 20:39:00 +10:00
Andreas Florath
f314df12c3 Refactor: use lazy logging
As described in pep282 [1], the variable part of a log message
should be passed in via parameter.  In this case the parameters
are evaluated only when they need to be.

This patch fixes (unifies) this for DIB.

A check using pylint was added that this kind of passing parameters to
the logging subsystem is enforced in future.  As a blueprint a similar
(stripped-down) approach from cinder [2] was used.

[1] https://www.python.org/dev/peps/pep-0282/
[2] https://github.com/openstack/cinder/blob/master/tox.ini

Change-Id: I2d7bcc863e4e9583d82d204438b3c781ac99824e
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-05-30 14:39:58 +10:00
Ian Wienand
3fdd9df983 Move create_graph into config.py
This was suggested in a review comment in
I8a5d62a076a5a50597f2f1df3a8615afba6dadb2.  It works out quite nicely
because the BlockDevice() driver now doesn't need to know anything
about stevedore or plugins, and just works on the node list.  It also
simplifies the unit testing by not having to call create_graph through
a BlockDevice object.

Change-Id: I98512f6cf42e256d2ea8225a0b496d303bf357b8
2017-05-26 11:48:39 +10:00
Ian Wienand
deb832d685 Create and use plugin/node abstract classes
This completes the transitions started in
Ic5a61365ef0132476b11bdbf1dd96885e91c3cb6

The new file plugin.py is the place to start with this change.  The
abstract base classes PluginBase and NodeBase are heavily documented.
NodeBase essentially replaces Digraph.Node

The changes in level?/*.py make no functional changes, but are just
refactoring to implement the plugin and node classes consistently.
Additionally we have added asserts during parsing & generation to
ensure plugins are implemented PluginBase, and get_nodes() is always
returning NodeBase objects for the graph.

Change-Id: Ie648e9224749491260dea65d7e8b8151a6824b9c
2017-05-26 11:48:11 +10:00
Ian Wienand
75817ef205 Use networkx for digraph
This switches the code to use networkx for the digraph implementation.

Note that the old implementation specifically isn't removed in this
change -- for review clarity.  It will be replaced by a base class
that defines things properly to the API described below.

Plugins return a node object with three functions

 get_name() : return the unique name of this node

 get_nodes() : return a list of nodes for insertion into the graph.
  Usually this is just "self".  Some special things like partitioning
  add extra nodes at this point, however.

 get_edges() : return a tuple of two lists; edges_from and edges_to
  As you would expect the first is a list of node names that points to
  us, and the second is a list of node names we point to.  Usually
  this is only populated as ([self.base],[]) -- i.e. our "base" node
  points to us.  Some plugins, such as mounting, create links both to
  and from themselves, however.

Plugins have been updated, some test cases added (error cases
specifically)

Change-Id: Ic5a61365ef0132476b11bdbf1dd96885e91c3cb6
2017-05-26 11:42:10 +10:00
Ian Wienand
00da1982ce Add a more generic tree->graph parser
This moves to a more generic config parser that doesn't have plugins
parsing part of the tree.

I understand why it ended up that way; we have "partitions" key which
has special semantics compared to others keys and there was a desire
to keep it isolated from core tree->graph code.  But this isn't really
isolated; you have to reverse-engineer several module-crossing
boundaries, extras classes and repetitive recursive functions.

Ultimately, plugins should have access to the node graph, but not
participate in configuration parsing.  This way we ensure that plugins
can't invent new methods of configuration parsing.

Note: unit tests produce the same tree -> graph conversion as the old
method.  i.e. this is not intended to have a functional change.

Change-Id: I8a5d62a076a5a50597f2f1df3a8615afba6dadb2
2017-05-26 10:13:14 +10:00
Ian Wienand
4e08765f87 Move exception to it's own file (again)
Moving the exception didn't cause problems in
I925ed62bdc808f0e07862f6e0905e80b50fbe942, but in later changes where
we split blockdevice.py up a bit more, we can get a bit tangled with
circular imports.

Change-Id: I8297483f64c4e1deecd5ec88ee40e9198bb83589
2017-05-20 06:44:39 +00:00
Yolanda Robla
6d0b9abc0f Apply setfiles on all mountpoints
With new block device definition, where content of the image
can be mounted on different partitions, is not enough with
executing setfiles on root directory. Instead of that, expose
all the mountpoints on the image, and apply setfiles on them.

Change-Id: I153f979722eaec49eab93d7cd398c5589b9bfc44
2017-05-16 07:51:48 +02:00
Andreas Florath
e4e23897a1 Refactor: block-device filesystem creation, mount and fstab
This patch finalizes the block device refactoring.  It moves the three
remaining levels (filesystem creation, mount and fstab handling) into
the new python module.

Now it is possible to use any number of disk images, any number of
partitions and used them mounted to different directories.

Notes:

 * unmount_dir : modified to only unmount the subdirs mounted by
   mount_proc_sys_dev().  dib-block-device unmounts
   $TMP_MOUNT_PATH/mnt (see I85e01f3898d3c043071de5fad82307cb091a64a9)

Change-Id: I592c0b1329409307197460cfa8fd69798013f1f8
Signed-off-by: Andreas Florath <andreas@florath.net>
Closes-Bug: #1664924
2017-05-12 13:52:02 +02:00
Ian Wienand
b9c065de28 Remove args from BlockDevice() init
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
2017-05-12 09:36:23 +10:00
Ian Wienand
c74ba2fe74 Move to subparsers
Move argument parsing to subparsers, rather than positional arguments.
This better reflects the tool's role as a driver and allows
sub-commands to deal with arguments in a natural way.

Change-Id: Iae8c368e0f3fe47abfddb9e0a1558bd5b3423aee
2017-05-11 21:03:33 +10:00
Ian Wienand
a06c610a8c Move YAML parsing into cmd.py; default to env
This moves the YAML parameter parsing into the command-line driver.
It makes the argument optional so it can be taken from the environment
variable directly.  The parsed YAML is passed to the BlockDevice
object.

Change-Id: I6fa5e5b7d1fccfc7cf47d6e4a1fa6e560734680d
2017-05-11 15:22:41 +10:00
Ian Wienand
47140293b6 Move blockdevicesetupexception.py into blockdevice.py
Less is more when it comes to code :)

Change-Id: I925ed62bdc808f0e07862f6e0905e80b50fbe942
2017-05-11 15:22:41 +10:00
Ian Wienand
2a185ec6b6 block_device: reorder imports
Reorder imports to hacking standard (stdlib, third-party, project) [1]

[1] https://docs.openstack.org/developer/hacking/#import-order-template

Change-Id: I4aa73321e1e796ef6b8b079e42f90bf5c75388fe
2017-05-11 10:38:55 +10:00
Ian Wienand
0d8c4270c0 exec_sudo: check cmd for str, log output and raise exception
To avoid any confusion, commands passed to exec_sudo() should be a
list of "str"s.  Log a message if we see unicode issues.

This also adds a debug trace of all output.  stderr is captured.

This is modified to raise CalledProcessError on failure, like
check_call().  Calls that are ok to fail will need to explicitly catch
and ignore this.

The two calls that we expect to fail are wrapped

We wish to try rolling back if one of these command raises an
exception.  Modify the create handler to initiate rollback on all
exceptions.

Change-Id: Iee4fa41ffaf243e4728bf3a5eeec5c8fa8d2dadc
2017-05-11 09:45:25 +10:00
Adam Harwell
196b44f38a Fix py3 error in block-device
This is breaking the octavia py3 gates.
Introduced by: I7aa4fe0466e44846d8fa3194575d446fe4b5b2e6

Change-Id: I3d86482a2999197a60a81d42afc5ef7a6e71e313
2017-05-04 15:55:22 -07:00
Yolanda Robla
e21935626b Refactor block-device base functions.
As part of the final steps, refactor the bits belonging
to block device and functions. This is a partial refactor
from I3600c6a3d663c697b59d91bd3fbb5e408af345e4

Change-Id: I7aa4fe0466e44846d8fa3194575d446fe4b5b2e6
Co-Authored-By: Andreas Florath <andreas@florath.net>
2017-05-04 19:54:18 +00:00
Yolanda Robla
943f1ccf04 Refactor block_device: isolate the getval call
Add a new getval call that allows to retrieve values
from the block device. Also isolating the block device
information into a 'blockdev' dictionary entry, to better
return it with the getval command.

This is a refactor from the original code at
I3600c6a3d663c697b59d91bd3fbb5e408af345e4.

Change-Id: I93d33669a3a0ae644eab9f9b955bb5a9470cadeb
Co-Authored-By: Andreas Florath <andreas@florath.net>
2017-05-01 12:22:52 +02:00
Andreas Florath
803d40b0c6 Refactor block_device: passing command line parameters
The original approach was to pass each and every command
line parameter to the block device.  While the block device
functionality gets extended, this is not any longer practical.

Instead of passing in all the parameters separately this patch
collects these in a YAML file that is passed in to the block device
layer.

Change-Id: I9d07593a01441b62632234468ac25a982cf1a9f0
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-04-23 09:51:18 +00:00
Andreas Florath
57c9e0bb41 Use stevedore for plugin config of block device
This patch introduces stevedore plugin mechanism for use
with the block device layer.  This makes it possible that
other projects pass in their own block device plugins.

Change-Id: Id3ea56aaf75f5a20a4e1b6ac2a68adb12c56b574
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-03-24 21:42:47 +00:00
Ian Wienand
b04c58eca4 blockdevice.py: python3 fixes
keys() is an iterator in python3, so we need to make it list before
finding the first element

Change-Id: Ic158c7b2901c1a34ff417d3432fcefed4760ce24
2017-03-13 19:33:07 +11:00
Andreas Florath
866a06f92d Refactor: block-device partitioning cleanup
Now that the main partitioning refactor patch is merged, there is
a small relict of handling partitions still in the disk-image-create
main.

This patch moves the functionality from disk-image-create to the
block-device/partitioning module: it is mostly a rewrite of the
original bash code in python.

Change-Id: Ia73baeca74180a7bc9ea487da03ff56d6a3070ce
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-03-07 18:43:09 +11:00
Jenkins
0f224d3ae6 Merge "Check return of _load_state" into feature/v2 2017-02-06 23:41:50 +00:00
Andreas Florath
df1f583903 Check return of _load_state
In error scenarios there might be no loadable state available.
This patch adds some robustness handling this scenarios
by checking the result and possible bailing out.

Change-Id: I02e2731b14bec22c22db08d60d8d15db1911a84e
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-02-04 19:21:48 +00:00
Andreas Florath
a8953dd277 block-device: change top level config from dict to list
With the old configuration structure it was only possible
to use one image and one partition layout.  The new
block-device configuration uses a list at top level;
therefore it is possible to use multiple instances
of each element type.

Change-Id: I9db4327486b676887d6ce09609994116dbebfc89
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-02-03 20:15:39 +00:00
Andreas Florath
ec7f56c1b2 Refactor: block-device handling (partitioning)
During the creation of a disk image (e.g. for a VM), there is the need
to create, setup, configure and afterwards detach some kind of storage
where the newly installed OS can be copied to or directly installed
in.

This patch implements partitioning handling.

Change-Id: I0ca6a4ae3a2684d473b44e5f332ee4225ee30f8c
Signed-off-by: Andreas Florath <andreas@florath.net>
2017-01-24 19:59:10 +00:00
Andreas Florath
3d48a528c1 Refactor: block-device handling (local loop)
Block device handling can be somewhat complex - especially
when taking things like md, lvm or encryption into account.

This patch factors out the creation and deletion of the local
loop image device handling into a python library.

The main propose of this patch is to implement the needed
infrastructure.  Based on this, more advanced functions can be added.
Example: (advanced) partitioning, LVM, handling different boot
scenarios (BIOS, UEFI, ...), possibility of handling multiple images
(local loop image, iSCSI, physical hard disk, ...), handling of
different filesystems for different partitions / LVs.

Change-Id: Ib626b36a00f8a5dc3dbde8df3e2619a2438eaaf1
Signed-off-by: Andreas Florath <andreas@florath.net>
2016-09-08 04:31:01 +00:00