As for LUQueryInstances the first version just acquires a shared lock on all
nodes. In the future further optimizations are possible, as outlined by
comments in the code.

Reviewed-by: imsnah

This first version acquires a shared lock on all requested instances and
their nodes. In the future it can be improved by acquiring less locks if
no dynamic fields have been asked, and/or by locking just primary nodes.

Reviewed-by: imsnah

If a list with a duplicate value is passed to a lockset what the code
now does is to try to acquire the lock twice, generating a
double-acquire exception in the SharedLock code. This is definitely an
issue. In order to solve it we can either forbit double values in a list
or just delete the duplicates. In this patch we go for the latter
solution, removing any duplicate values when creating the acquire_list.

Reviewed-by: imsnah

If a locking level wasn't specified locking used to stop. This means
that if one, for example, didn't specify anything at the LEVEL_INSTANCE
level, no locks at the LEVEL_NODE level were acquired either. With this
patch we force _LockAndExecLU to be called for all existing levels, and
break the recursion if the level doesn't exist in locking.LEVELS.

Reviewed-by: imsnah

The check for the reboot type can be done without any locks held, so
we'll move it to ExpandNames. Plus, we note in a FIXME that if the
reboot type is not full, we can probably just lock the primary node, and
leave the secondary unlocked.

Reviewed-by: imsnah

Reviewed-by: schreiberal

By using this Linux-specific way we don't have to care about removing the
socket file when quitting or starting (after an unclean shutdown). For a
more detailed description, see the comment in the patch.

Reviewed-by: schreiberal

This option will be used to add nodes to the cluster without
asking the user to confirm the key. Together with key based
authentication this can be used in the QA tests.

Reviewed-by: ultrotter

This will be used to add nodes without user interaction, specifically
in QA tests.

Reviewed-by: ultrotter

I'm going to add another option and it would make maintaining
them in constants even more complicated.

Reviewed-by: ultrotter

This patch changes SshRunner.Run to pass all arguments to
SshRunner.BuildCmd. They had the same arguments before
and should stay that way. This change makes it easier
to add new or change existing arguments.

Reviewed-by: ultrotter

It's handy to make the os scripts know which hypervisor the instance is
going to run under. In order not to change the os API we pass this
information in the environment, where the os scripts can access it if
they're hypervisor-aware.

Reviewed-by: imsnah

If the user passes an env dict to RunCmd we'll override the environment
passed to the to-be-executed command with the values in the dict. This
allows us to pass arbitrary environment values to commands we run.

Reviewed-by: imsnah 

- Remove a few experiemental code lines left as comments
- Rework first disks' boot=on addition, which was calculated twice
- Remove an empty line
- Remove reference to hvm_pae which doesn't apply to kvm

Reviewed-by: imsnah

ht_kvm.py contains the code for ganeti to work under kvm.
This patch also modifies Makefile.am to ship that file, and
lib/hypervisor/__init__.py to import it, and add kvm to the
hypervisors map.

Reviewed-by: imsnah

Add a new hypervisor type, HT_KVM, to constants, and register it in the
HYPER_TYPES set.

Reviewed-by: imsnah

This allows to configure a different path to the kvm binary. By default
/usr/bin/kvm is used, which is the one found in debian and ubuntu.

Reviewed-by: imsnah

StartInstance takes 'block_devices', not 'force' as its third argument.
Even if this is not used in the fake hypervisor it's better to have the
correct argument name to avoid confusion.

Reviewed-by: imsnah

Reviewed-by: imsnah

If a node hasn't been part of the cluster before being added it'll not
have the cluster's SSH key. This patch makes sure to accept those by
not aliasing the machine name to the cluster name.

Reviewed-by: ultrotter

Noded didn't release the job queue lock after initialising it. This
patch makes sure to unlock once the work is done.

Reviewed-by: ultrotter

This means commands will not take at least one second anymore.

Reviewed-by: ultrotter

This way clients can react faster to status or message changes and
don't have to poll anymore.

Reviewed-by: ultrotter

See the comment in the patch.

Reviewed-by: ultrotter

These will be used for job logs.

Reviewed-by: ultrotter

Reviewed-by: iustinp

The lock should only be removed if ganeti-noded is going to quit.
Otherwise it needs to be kept to prevent another process from creating
it again while we're still holding the (removed) lock. This is due to
POSIX filesystem semantics.

Reviewed-by: iustinp

The code cleaning the queue will make use of it.

Reviewed-by: iustinp

Otherwise one might have archived jobs back in the list after a master
failover.

Reviewed-by: iustinp

This will be used to archive jobs.

Reviewed-by: iustinp

Another function will need to check whether its parameters
are job queue files.

Reviewed-by: iustinp

Reviewed-by: iustinp

This way we can do locking when both noded and masterd are running
on the same machine, the latter holding an exclusive lock on the
queue.

Reviewed-by: iustinp

Otherwise users might be confused by errors in log files.

Reviewed-by: iustinp

The job queue is now updated through its own RPC functions.

Reviewed-by: iustinp

Reviewed-by: iustinp

jobqueue_update: Uploads a job queue file's content to a node. The
most common operation is to upload something that we already have
in a string. Unlike in the upload_file function, the file is not
read again when distributing changes, but content has to be passed
as a string.

jobqueue_purge: Removes all queue related files from a node.

Reviewed-by: iustinp

JobQueuePurge() will be used by an RPC function.

Reviewed-by: iustinp

feedback_fn wasn't passed to it.

Reviewed-by: iustinp

By doing this we've a central place which coordinates what needs to be
done when adding or removing nodes. Another patch will add calls into
the job queue.

Two log messages move to config.py.

When removing a node, node_leave_cluster is now called after it has
been removed from the configuration and job manager. That way we're
sure not to access the node again after files have been removed.

Reviewed-by: iustinp