Includes some locking-related constants and explanations on how the
LockManager should be used, the class itself and its test cases.

The class includes:
  - a basic constructor
  - functions to acquire and release lists of locks at the same level
  - functions to add and remove list of locks at modifiable levels
  - dynamic checks against out-of-order acquisitions and other illegal ops

Its testing library checks that the LockManager behaves correctly and that the
external assumptions it relies on are respected.

Reviewed-by: imsnah

A LockSet represents locking for a set of resources of the same type. A thread
can acquire multiple resources at the same time, and release some or all of
them, but cannot acquire more resources incrementally at different times
without releasing all of them in between.

Internally a LockSet uses a SharedLock for each resource to be able to grant
both exclusive and shared acquisition. It also supports safe addition and
removal of resources at runtime. Acquisitions are ordered alphabetically in
order to grant them to be deadlock-free. A lot of assumptions about how the
code interacts are made in order to grant both safety and speed; in order to
document all of them the code features pretty lenghty comments.

The test suit tries to catch most common interactions but cannot really tests
tight race conditions, for which we still need to rely on human checking.

This is the second basic building block for the Ganeti Lock Manager. Instance
and Node locks will be put in LockSets to manage their acquisition and release.

Reviewed-by: imsnah

Reviewed-by: iustinp

- Check that even a shared acquire() fails on a deleted lock
- Check that delete() fails on a lock you share (must own it or nothing)

These are assumptions I build on in future code, so better check for them.
Currently no code change is necessary for them to be valid.

Reviewed-by: iustinp

The _doItDelete helper code was supposed to be used to dispatch threads that
deleted the SharedLock. It actually just acquired it exclusively. This remained
unnoticed as the helper thread is just used to test interaction, not the delete
code by itself, and delete requires an exclusive acquire anyway.

Reviewed-by: imsnah

This new operation lets a lock be cleanly deleted. The lock will be exclusively
held before deletion, and after it pending and future acquires will raise an
exception. Other SharedLock operations are modify to deal with delete() and to
avoid code duplication.

This patch also adds unit testing for the new function and its interaction with
the other lock features. The helper threads are sligtly modified to handle and
report the condition of a deleted lock. As a bonus a non-related unit test
about not supporting non-blocking mode yet has been added as well.

This feature will be used by the LockSet in order to support deadlock-free
delete of resources. This in turn will be useful to gracefully handle the
removal of instances and nodes from the cluster dealing with the fact that
other operations may be pending on them.

Reviewed-by: iustinp

Use the actual class name rather than a spaced version of it.

Reviewed-by: iustinp

Adding a locking.py file for the ganeti locking library. Its first component is
the implementation of a non-recursive blocking shared lock complete with a
testing library.

Reviewed-by: imsnah, iustinp

In revision 459 I added a bug in the make dist rule in the sense that
the archive will include *all* of test/data directory, including the
.svn directory if it exists.

This patch fixes that problem and adds a distcheck hook that tests for
such errors in the future (files/directories matching the .svn and .git
patterns).

It also fixes a typo in the NEWS file.

Reviewed-by: imsnah

This patch fixes the ‘make distcheck’ breakage caused by missing test data in
the archive and missing handling of builddir!=srcdir case.

Reviewed-by: schreiberal

This patch changes the bdev.DRBD8._GetDevInfo to take a string instead
of a minor, separates the `drbdsetup show` invocation into a new
separate method (bdev.DRBD8._GetShowData) and modifies the rest of the
DRBD8 class to make the appropriate calls.

It also adds a unittest script and data files for testing various cases
of device output.

Reviewed-by: imsnah

Reviewed-by: imsnah

Reviewed-by: iustinp

Reviewed-by: ultrotter

Reviewed-by: schreiberal

Reviewed-by: schreiberal

Reviewed-by: ultrotter

Reviewed-by: schreiberal, ultrotter

Reviewed-by: schreiberal

- Combine hostname and aliases on one line
- Fix bug with wrongfully removed newline characters
- Use wrapper for SetEtcHostsEntry in cmdlib

Reviewed-by: iustin

Reviewed-by: TODO

Currently, an unreachable node (or one that return undetermined failure)
in the hooks pre-phase will abort the curren operation. This is not
good, as a down node could prevent many operation on the cluster.

This patch changes a RPC-level failure (and not a hook execution
failure) into a warning. It also modifies the related test cases.

This fixes issue 11.

Reviewed-by: ultrotter

Reviewed-by: schreiberal

Reviewed-by: schreiberal

Reviewed-by: imsnah

This removes the dependency on either the uuid module or e2fsprogs' uuidgen.

Reviewed-by: iustinp

This patch completely  gets rid of fping
 - replace all fping invocations with TcpPing calls
 - update documentation accordingly.
 - associated cleanups (use constant for localhost IP, use more sensible
   defaults for TcpPing and _use_ those)

Reviewed-by: iustinp

Since modules are not directly executables, remove the shebang from
them. This helps with lintian warnings.

Also make the autogenerated _autoconf.py contain two comment lines at
the beginning, like the other modules.

Reviewed-by: ultrotter

- Move symlink to “ganeti” to top dir
- Add ganeti.config_unittest.py to tests to be run
- Make sure everything is built before tests are run

Reviewed-by: iustinp

dot.

Reviewed-by: iustinp

Reviewed-by: schreiberal

We currently require that hostnames are FQDN not short names
(node1.example.com instead of node1). We can allow short names as long
as:
  - we always resolve the names as returned by socket.gethostname()
  - we rely on having a working resolver

These issues are not as big as may seem, as we only did gethostname() in
a few places in order to check for the master; we already required
working resolver all over the code for the other nodes names (and thus
requiring the same for the current node name is normal).  The patch
moves some resolver calls from within execution path to the checking
path (which can abort without any problems). It is important that after
this patch is applied, no name resolving is called from the execution
path (LU.Exec() or other code that is called from within those methods)
as in this case we get much better code flow.

This patch also changes the functions for doing name lookups and
encapsulates all functionality in a single class.

The final change is that, by requiring working resolver at all times, we
can change the 'return None' into an exception and thus we don't have to
check manually each time; only some special cases will check
(ganeti-daemon and ganeti-watcher which are not covered by the
generalized exception handling in cli.py). The code is cleaner this way.

Reviewed-by: imsnah

Reviewed-by: iustinp, imsnah

To be used to replace the currently fping(8) based reachability test.

Reviewed-by: imsnah