This patch removes the options that allow to create local_raid1 or
remote_raid1 instances. It also modifies the documentation and removes
these disk templates from burnin and from qa.

Reviewed-by: imsnah

These two operations are related to md/drbd7 code (remote_raid1). Remove
them as part of the md/drbd7 removal.

Reviewed-by: imsnah

This patch adds three things:
- it normalizes the file storage directory path passed to gnt-cluster init
- if the file-storage-path doesn't exist on the master node, ganeti
  tries to create it
- adds additional check if the passed file-storage-dir is not a directory

Reviewed-by: iustinp

The BlockDev.GetStatus() method and some associated constants were never
used in the rest of the code. This patch removes them.

Reviewed-by: imsnah

This patch adds a new top-level class (BaseJO) that is used for both
opcodes and a new Job class.

This new class and the related changes to the OpCode abstract class are
used to implement simple to-dict/from-dict transformations, so that we
can easily serialize the classes using json.

Reviewed-by: imsnah

Author: manuel.franceschini
Reviewed-by: iustinp

Author: manuel.franceschini
Reviewed-by: iustinp

Author: manuel.franceschini
Reviewed-by: iustinp

Author: manuel.franceschini
Reviewed-by: iustinp

Author: manuel.franceschini
Reviewed-by: iustinp

Author: manuel.franceschini
Reviewed-by: iustinp

This adds the possibility to specify at configure-time the default file-storage-dir.

Author: manuel.franceschini
Reviewed-by: iustinp

Currently in order to deal with tmpfs /var/run, we create the
BDEV_CACHE_DIR in the init script. However, that does not cover all the
cases, and it's not a proper place to deal with it: for example, dealing
with not initialized clusters and the master node is more complicated.

Therefore, this patch does:
  - make ganeti-noded create the directory automatically
  - make ganeti-noded error out if it can't create it or it's already
    there but not a directory
  - remove the creation from the init.d script

Reviewed-by: ultrotter

Reviewed-by: ultrotter

This replaces very old code.

Reviewed-by: ultrotter

Reviewed-by: ultrotter

Reviewed-by: ultrotter

This allows callers to allocate a pseudo-TTY easily.

Reviewed-by: ultrotter

Reviewed-by: ultrotter

This renames some functions and does some minor codestyle cleanup.

Reviewed-by: ultrotter

The whole Ganeti cluster has a single SSH key. Its fingerprint is
written to Ganeti's known_hosts file, together with an alias. This
allows us to always use that alias instead of the real hostname,
making management of the known_hosts file much easier.

This patch does not handle an upgrade from an earlier version.

Reviewed-by: ultrotter

Reviewed-by: imsnah

Previously if a shared thread was notified, together with the rest, and was not
fast enough in waking up and acquiring the lock, another one could release it,
decide there were no more sharers, and let an exclusive one in instead. With
this patch we make sure all the shared holders which were waiting have passed,
before declaring it's time to make an exclusive one pass.

This also allows us to reintroduce a slight variation of the assertion removed
in r665, which makes our code safer.

Reviewed-by: imsnah

The -s option when changing secondary node on a drbd template is implied, and
thus optional. Specify this in the manpage.

Reviewed-by: iustinp

Make the cluster init fail if the IP to which the cluster name resolved
is already reachable by the master node. This is not a foolproof
solution, but it allows a cheap method of detecting simple mistakes.

It will also disallow using the master node name as cluster name (which
is something good).

The only drawbacks that I see are:
  - you are not allowed to do this, which might come in handy in cluster
    upgrades; but since we support rename, this is mitigated
  - cluster init takes longer now (+the timeout value, set to 5
    seconds), but since this is a one-off operation, it should be ok

Reviewed-by: ultrotter

This patch modifies TcpPing and its callers to make the source address
selection optional. Usually, the kernel will know better what
source address to use, just in some cases we want to enforce a given
source address so it makes sense to make this optional.

Reviewed-by: ultrotter

The "quick" online help just reported the option to change secondary node. Add
the ones to just replace the disk locally on-primary or on-secondary. It is of
course impossible to espress in one line everything needed to use this command,
but at least now the most common options are spelled out immediately.

Reviewed-by: iustinp, imsnah

Reviewed-by: ultrotter

Reviewed-by: ultrotter

A LockSet is mostly useful when it has some locks in it. On the other hand
there are cases in which it must function even when empty. For example if a
cluster has no instances in it there's no reason why locking all of them
shouldn't work anyway. This patch adds test code for that situation and
implements the necessary fixes to make it work.

Reviewed-by: imsnah

This check that no operation had been performed before release() was missing in
the test code. Adding it.

Reviewed-by: imsnah

Reviewed-by: imsnah

r644 contained some cleanup code for LockSet. Among other things it removed a
syntax error that allowed an assertion that previously wan't really checked to
trigger. It turns out that even though the spirit of that assertion was correct
its actual implementation was wrong.

While it's true that no sharers must be waiting if an exclusive holder is not
present it might happen that when all the sharers wake up one of them releases
the lock before some other even has had a chance to run. In this case
__shr_wait would still be greater than 0, even if the sharer is not actually
waiting, just pending a wakeup to proceed.

Thus, removing the assertion in question.

Reviewed-by: imsnah

Reviewed-by: ultrotter

This new functionality makes it possible to acquire a whole set, by passing
"None" to the acquire() function as the list of elements. This will avoid new
additions to the set, and then acquire all the current elements. The list of
all elements acquired will be returned at the end.

Deletions can still happen during the acquire process and we'll deal with it by
just skipping the deleted elements: it's effectively as if they were deleted
before we called the function. After we've finished though we hold all the
elements, so no more deletes can be performed before we release them.

Any call to release() will then first of all release the "set-level" lock if
we're holding it, and then all or some of the locks we have.

Some new tests checks that this feature works as intended.

Reviewed-by: imsnah

This patch adds a try/except area around most of the acquire() code (everything
after the intial condition checks). Since the except: clause contains just a
'raise' nothing really changes except the indentation of the code.

This is done in a separate commit to insulate and make clearer what the real
code changes done in the upcoming patch are.

Reviewed-by: imsnah

Previously the private version of the __names function returned directly a set.
We'll keep this in the public interface but change the private version to a
list in order to be able to sort() its result and then loop on it, even though
we'll need to do this with the usual care that some keys may disappear in
between.

Reviewed-by: imsnah

Lockset's remove() function used to return a list of locks we failed to remove.
Rather than doing this we'll return a list of removed locks, so it's more
similar to how acquire() behaves. This patch also fixes the relevant unit tests.

Reviewed-by: imsnah

In a LockSet acquire() returned True on success. This code changes that to
return a set containing the names of the elements acquired. This is still a
true value if we acquired any lock but is slightly more useful (because if
needed one has access to this data without querying for it). The only change
happens if acquiring no locks, which though is a usage which should not
normally happen because it has no practical use.

The patch also changes a some tests to check that the new format is respected.

Reviewed-by: imsnah

This patch changes nothing to the functionality of a LockSet. Rather than
trying to do the whole for loop we try each of its steps. This opens the way to
handle differently a single failure.

Reviewed-by: imsnah