A job queue with too many jobs can increase memory usage and/or make
the master daemon slow. The current limit is just an arbitrary number.
A "soft" limit for automatic job archival is prepared.

Reviewed-by: iustinp

This patch should fix all outstanding epydoc parsing errors; as such, we
switch epydoc into verbose mode so that any new errors will be visible.

Reviewed-by: imsnah

We add a (per-node) queue drain flag that blocks new job submission.
There is not yet an interface to add/remove the flag (will come in next
patches).

Reviewed-by: imsnah

This patch adds a generic method to identify the ganeti error given its
class name, and implements this across the luxi protocol.

Reviewed-by: imsnah

Currently this is not derived from GenericError, but there's no reason
for it to be so.

Reviewed-by: imsnah

It's not perfect and it's not finished, but it's a start.

- Serial number is read only once, but written on each update
- Jobs are kept only on disk (caching will be implemented)

Reviewed-by: iustinp

Rather than packing all the arguments in a tuple, let's pass them
plainly. The superclass won't complain.

Reviewed-by: iustinp

This exception does not signal an error but serves the purpose of making
the ganeti daemon shut down after handling a request. Currently it will
be used by ganeti-noded but in the future ganeti-masterd might make use
of it as well. Its usage is documented in the docstring.

Reviewed-by: iustinp

Reviewed-by: iustinp

Reviewed-by: iustinp

This patch converts the cli.py SubmitOpCode method to use the unix
protocol and thus execute the opcodes via the master.

The patch allows a partial burnin to work with the master. Currently the
query opcodes, since they are executed via the SubmitOpCode, are
executed inside a job too, which is suboptimal, but they work fine.

The cmd lock has been removed from the master, but the cli.py still
takes the lock. This is ok for this in-progress patch (since the master
still has only one executor thread). This will be fixed in a future
patch.

Reviewed-by: ultrotter

Since modules are not directly executables, remove the shebang from
them. This helps with lintian warnings.

Also make the autogenerated _autoconf.py contain two comment lines at
the beginning, like the other modules.

Reviewed-by: ultrotter

- Document the expected change to errors.InvalidOS
- Always pass the additional argument
- Modify DiagnoseOS output to show the path


Reviewed-by: iustinp, imsnah

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 is only the backend part, from the command line the tags can't be
read/modified yet.

Reviewed-by: imsnah

Reviewed-by: iustinp