During cluster init, set the default hypervisor to be used for instances.
Ensure that the default hypervisor belongs to the set enabled hypervisors
for this cluster. Also fix a small bug with setting the default enabled
hypervisor list.

Reviewed-by: imsnah

We no longer use a single, cluster-wide hypervisor, but configure the
actual to be used hypervisor on the instance level.

Reviewed-by: imsnah

Reviewed-by: iustinp

If we don't actually know the current master (as determined via voting),
we prevent the failover.

The patch also changes some messages (capitalization, typos).

Reviewed-by: ultrotter

In order to account for future improvements to master failover, we move
the actual data gathering capabilities from ganeti-masterd into
bootstrap.py, and we leave only the verification into masterd.

The verification procedure is then changed to retry multiple times (up
to one minute) in case most nodes do not respond, and also the algorithm
is changed to require at least half (but not half+1) votes, since our
vote also should count (and we vote for ourselves).

Example for consistent (config-wise) cluster:
  - 5 node cluster, 2 nodes down: still start
  - 4 node cluster, 2 nodes down: retry for one minute, abort

Reviewed-by: ultrotter

Currently, we check if we have a given ip address (i.e. it's alive on
one of our interfaces) but manually calling TcpPing(source=localhost).
This works, but having it spread all over the code makes it hard to
change the implementation.

The patch abstracts this into a separate utils.OwnIpAddress(addr)
function. We add a rpc call for it, which we use instead of the
(single-use of) call_node_tcp_ping. We leave node_tcp_ping in, as seems
useful and eventually it should be removed in a separate patch.

Reviewed-by: imsnah

This big patch changes the call model used in internode-rpc from
standalong function calls in the rpc module to via a RpcRunner class,
that holds all the methods. This can be used in the future to enable
smarter processing in the RPC layer itself (some quick examples are not
setting the DiskID from cmdlib code, but only once in each rpc call,
etc.).

There are a few RPC calls that are made outside of the LU code, and
these calls are left as staticmethods, so they can be used without a
class instance (which requires a ConfigWriter instance).

Reviewed-by: imsnah

Indentation in bootstrap was wrong and some names in cmdlib.py were not
right.

Reviewed-by: imsnah

Since in 2.0 the user will possibly have more interaction with the
hypervisor names, we sanitize them by removing the version numbers
(the version can be a prerequisite for the ganeti installation, we
shouldn't document it in variable names).

Reviewed-by: schreiberal

Reviewed-by: iustinp

More places actually use the SshRunner than just the gnt-cluster
commands.

Reviewed-by: ultrotter

Remove leftovers from ssconf.

Reviewed-by: iustinp

Replace ssconf with configuration.

Reviewed-by: iustinp

Get rid of ssconf and convert to configuration instead.

Reviewed-by: iustinp

ssconf will become write-only from ganeti-masterd's point of view,
therefore all settings in there need to go into the main configuration
file.

Reviewed-by: iustinp

Future patches will add even more variables to the cluster config.
Adding more parameters wouldn't make the function easier to use and
it doesn't make sense to pass them to another function, as it's
only done once in bootstrap.py on cluster initialization.

Reviewed-by: iustinp

The bootstrap code needs a pseudo-secret and this is currently generated
inside the InitGanetiServerSetup function. Since more users will need
this, move it to utils.py

Reviewed-by: ultrotter

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

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

With the recent startup/shutdown changes (and with the master daemon in
place), the cluster destroy needs some fixing.

This patch moves the finalization of the destroy out from cmdlib into
bootstrap, so we can nicely shutdown the rapi and master daemons.

Reviewed-by: ultrotter

With the recent changes, I forgot the extra parameter to this rpc call.
Also the rpc call needs to be done after we setup the config data, for
the master daemon to be able to start, so we move it after all other
init steps.

Reviewed-by: ultrotter

Reviewed-by: imsnah

This (big) patch reworks the master startup/shutdown and the fixes the
master failover.

What does the patch do?

For master start/stop:
  - remove the old ganeti-master script and its associated man page
  - moves the ip start/stop directly into the backend.(Start|Stop)Master
  - adds start/stop of the master/rapi daemon into these functions,
    selectively based on the start/stop arguments
  - makes the master call via rpc StartMaster(start_daemons=False) to
    the local node so that the master IP is started
  - and finally changes the example init.d script to directly start and
    stop all three daemons, since they do the right thing (depending on
    master/not master role)

For master failover:
  - moves the code from LUMasterFailover into bootstrap.MasterFailover,
    since we need to start/stop the master during this operation and
    thus it can't be executed from the master
  - removes the LUMasterFailover and its associated opcode

Notes: ubuntu's /etc/lsb-base-logging.sh is dumb, so the messages 'not
master' are not seen during startup on non-master nodes.

Reviewed-by: ultrotter

From the master node we can't start ssh and connect to the remote node,
nor we can do it from ganeti-noded as this ssh section will possibly ask
for key confirmation and password. So the code to copy the ganeti-noded
password and SSL key has been moved to bootstrap.py, and it's called by
gnt-node before the AddNode opcode.

Reviewed-by: iustinp

Before we used to be able to update SimpleStore by just calling SetKey, this
feature is now moved to an external class, which inherits from it. In this
patch the new WritableSimpleStore class is also put to use, in the LUs that
need it. Rather than making each LU instantiate it, we have a new LogicalUnit
flag REQ_WSSTORE which defaults to False, but when declared to be True asks the
LogicalUnit to be initialized with a writeable version of the SimpleStore.
LUMasterFailover and LURenameCluster are then changed to use it.

InitCluster is also changed to instantiate a WritableSimpleStore, rather
than a normal one.

Reviewed-by: imsnah

This allows us to initialize a new cluster. The code certainly contains
bugs and hooks aren't implemented yet.

Reviewed-by: iustinp