As far as I understand, this was just a debugging aid. Remove it so that
configuration errors are nicely handled.

Reviewed-by: imsnah

- Add NEWS file with major changes between versions.
- Bump RPC version number
- No longer serialize in RPC, but just convert to dict

Old Pickle based configuration files can be converted using the cfgupgrade
utility.

Reviewed-by: iustinp, ultrotter

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

This patch adds support for renaming instances to the ConfigWriter
class. It's needed in here in order to guarantee that we don't lose the
instance during the rename (the instance will be there, either with the
old name or with the new name).

Reviewed-by: imsnah

This changes the raising of exceptions from:
  raise Exception, value
to
  raise Exception(value)

as the first form will be removed in python-3000 and the second form is
preferred now.

The changes also involve a few cases of changing from raising standard
exceptions and use our own ones.

The new version also fixes many pylint-generated warnings, especially in
ganeti-noded where I changed many methods to @staticmethod.

There is no functionality changed (barring any bugs).

  - add an Update method on the ConfigWriter class;
  - make the AddInstance method not log disks for diskless types (helps with testing)
  - implement limited testing for the ConfigWriter with focus on the new Update method

won't reread it if not modified by someone else.

configuration.

Reviewed-by: imsnah

instead use an UUID prefix and a suffix denoting the disk iv_name
(sda/sdb) and possibly it's type (data/meta).

Reviewed-by: imsnah

Reason: if left ConfigWriter, nodes don't know to which cluster they belong.
This will bite us later when we'll revisit node join operation.

Cons: we lose the cluster name from the config file, which means a
standalone "cluster.data" is a little bit harder to analyze. But I have
a plan for this which will follow shortly.

Implementing this will also allow us to cleanly fix "gnt-cluster
getmaster".

Reviewed-by: imsnah

Reviewed-by: iustinp

Reviewed-by: iustinp

and all users have been converted, let's remove it from the slots of the
cluster object.

Also let's move the tcpudp_port_pool to the cluster object.

Reviewed-by: imsnah

Reviewed-by: iustinp

  - move the master node name from the ConfigWriter to SimpleStore (all
    nodes need this, and it was the only thing pulled in from the
    ConfigWriter on nodes)
  - fix mcpu.py and the testing w.r.t. this change; for testing, rename
    the fake_config.py to mocks.py and add a FakeSStore object
  - then add a ganeti-master script which can be run on any node at boot
    and which will not do anything if not master on start (on stop it
    will still try to remove the ip address)
  - also add a new cluster-wide variable (master_netdev) that determines
    on which interface we add this ip address; it's customizable at
    cluster init time
  - also remove the cluster name file which was separately handled from
    ssconf (not needed anymore)
  - remove the master init.d links from the list of config files as this
    is not our responsibility now