This patch does two things:
- Add gnt-cluster modify
- Add --no-lvm-storage option to gnt-cluster init

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

This patch does two things:
- Remove "vg_name" from _OP_REQP due to the introduction of
  --no-lvm-storage. Since vg_name option has as default now None and is
  only set to the DEFAULT_VG if lvm_storage is enabled, this is needed
- It changes LUInitCluster.CheckPrereq() to skip _HasValidVG check
  initializing the cluster with --no-lvm-storage. Furthermore it adds to
  the help message the statement of the possibility to use
  --no-lvm-storage if no 'xenvg' volume group is found.

Reviewed-by: iustinp

Add LUSetClusterParams, which is the LU to modify cluster options.
This includes checks:
- not to disable lvm storage when it's already disabled
- not to enable lvm storage when it is already enabled
- not to disable lvm when lvm-based instances are present
- that the specified volume group is valid on all cluster-nodes
  when lvm-storage is going to be enabled

Reviewed-by: iustinp

Reviewed-by: iustinp

This adds a check to fail instance creation if lvm-storage is disabled
(cluster-wide). If lvm-storage is disabled (by initializing the cluster
with --no-lvm-storage) only instances with disk template in frozenset
DTS_NOT_LVM are allowed to create.

Reviewed-by: iustinp

DTS_NOT_LVM:
This constant is needed when checking if an instance can be created with
the given disk template if no lvm-storage is available, i.e. the ganeti
cluster does not have a volume group

DEFAULT_VG:
'xenvg' has been hardcoded before.

Reviewed-by: iustinp

In the start and stop instance LUs, the configuration update is done
right at the end. This means that if, for example, the instance shutdown
succeeds, but the drive deactivation fails, the next run of the watcher
will start the instance again, as it's still marked in running mode.

This patch changes these two LUs so that first the update the
configuration to the desired state, and only then we proceed to update
the config. This ensures that the state saved is the desired state.

Because the config might be updated even though the LU failed, this
patch also modifies the mcpu.Processor.ExecOpCode method to run the
RunConfigUpdate hook in a finally: phase while the lu.Exec is done in
its try phase. This ensures that config update hooks (tries to) run at
all times when the config is updated.

Reviewed-by: schreiberal

This oneliner fixes a bug in listing more than twenty instances for
multiple operations (shutdown, startup, etc.).

Reviewed-by: imsnah

This patch just removes an extraneous \n from the log message making it
nicer to view.

Reviewed-by: schreiberal

Reviewed-by: iustinp

This enables us to run automated tests on “gnt-instance console”, at least
to some degree.

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

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