Since the context is passed to LogicalUnit, rather than the cfg, we can
only access the cfg as self.cfg, self.context.cfg, or context.cfg (in
the constructor). cfg is not valid anymore.

Reviewed-by: iustinp

Whenever we add an instance or node to the cluster (i.e. to the config
and whenever we remove them we should add/remove locks as well). In the
future we may want to optimize this so that the configwriter does it, or
it's handled at the context level, but till we're adding/removing
instances and nodes with the BGL held it doesn't matter too much.

Reviewed-by: iustinp

Rather than passing a ConfigWriter to the LUs we'll pass the whole
context, from which a ConfigWriter can be extracted, but we can also
access the GanetiLockManager. This also fixes the places where a FakeLU
is created.

Reviewed-by: iustinp

This will be passed to FakeLUs

Reviewed-by: iustinp

Reviewed-by: iustinp

Since the ConfigWriter now handles its own locking it's not necessary to
have a specific level for the config in the Locking Manager anymore.
This patch thus removes it, and all the unittest calls that used it, or
depended on it being present.

Reviewed-by: iustinp

Since we share the ConfigWriter we need somehow to make sure that
accessing it is properly synchronized. We'll do it using the
locking.ssynchronized decorator and a module-private shared lock.

This patch also renames a few functions, which were called inside the
ConfigWriter, to a private version _UnlockedFunctionName, and exports
the synchronized public ones. The internal callers, which are already
synchronized, are then changed to use the _Unlocked version, to prevent
double locking.

Reviewed-by: iustinp

This patch creates a new decorator function ssynchronized in the locking
library, which takes as input a SharedLock, and synchronizes access to
the decorated functions using it. The usual SharedLock semantics apply,
so it's possible to call more than one synchronized function at the same
time, when the lock is acquired in shared mode, and still protect
against exclusive access.

The patch also adds a few unit test to check the basic decorator's
functionality, and to provide an example on how to use it.

Reviewed-by: iustinp

Remove empty function _ReleaseLock and all its calls. Since we only
have one configwriter per cluster the locking needs to cover all the
data in the object, and not just the file contents. Locking in
ConfigWriter will be handled using the ganeti locking library.

Reviewed-by: iustinp

This patch fixes two bugs:
  - the state file is not saved because we use the method for checking
    for udpated data
  - in two places 'Error' was used instead of 'Exception', which breaks
    error handling

Additionally:
  - the unused 're' import has been removed
  - a variable named 'id' which collides with a builtin function has
    been renamed

Note that comparing the serialized forms might create false negatives
(due to the dicts being reordered) but that will just cause an extra
write of the file, which is sub-optimal but harmless.

Reviewed-by: ultrotter

Reviewed-by: ultrotter

By a mistake, we don't reuse the luxi client. As such, we open and close
the connection at each poll cycle and spam the server logs.

Reviewed-by: ultrotter

It's better for daemons if:
  - they log only to one log file
  - the log level is included
  - for debug runs, the filename/line number is included

This patch moves the custom formatter from the watcher to the logging
module and generalizes it; then it changes the master daemon to use this
function instead of the generic logging (which might be deprecated
anyway in the future).

Reviewed-by: imsnah

The gnt-instance script doesn't run in the same process anymore, so we
can't and don't have to unlock.

Reviewed-by: ultrotter

Reviewed-by: iustinp, ultrotter

Reviewed-by: ultrotter, iustinp

Make the GanetiLockManager instance of GanetiContext lowercase

Reviewed-by: imsnah

At least docbook2man inserts a date formatted using the current
locale into its output.

Reviewed-by: iustinp

Reviwed-by: imsnah

This function will return the first unused integer based on a list of
used integers (e.g. [0, 1, 3] will return 2).

Reviewed-by: imsnah

Now that we use the locking library to make sure running opcodes cannot
step on each other toes we can have a bigger thread size, and
potentially process many opcodes in a parallel manner.

Reviewed-by: iustinp

If a LU required the BGL (all LUs do, right now, by default) we'll
acquire it in the Processor before starting them. For LUs that don't
we'll still acquire it, but in a shared fashion, so that they cannot run
together with LUs that do.

We'll also note down whether we own the BGL exclusively, and if we don't
and we try to chain a LU that does, we'll fail.

More work will need to be done, of course, to convert LUs not to require
the BGL, but this basic infrastructure should guarantee the coexistance
of the old and new world for the time being.

Reviewed-by: iustinp

The processor used to create a new ConfigWriter when it was initialized.
We now have one in the context, so we'll just recycle it. First of all
we'll pass the context in when creating a new Processor object, then
we'll just use context.cfg, which is granted to be initialized, wherever
we used self.cfg, and stop checking whether the config is already
initialized or not.

In the future the Processor will be able to use the context also to
acquire the BGL for LUs that require it, and to push the context down to
LUs that don't in order for them to manage their own locking.

Reviewed-by: iustinp

When logical units have REQ_BGL set (it is currently the default) they
need to be the only ganeti operation run on the cluster, and we'll
guarantee it at the master daemon level. Currently only one thread is
running at a time, so this requirement is never broken.

Reviewed-by: iustinp

In 2.0 burnin submits job to the master daemon, so it doesn't need to
create an internal Processor anymore. Even if the processor is not used
anywhere in the burnin code it was still initialized as a leftover of
how burnin used to work. Fixing this.

Reviewed-by: iustinp

This adds the same “-o +...” functionality in gnt-job as in the node and
instance scripts.

Reviewed-by: imsnah

- no need to keep the sstore as an object member, remove it
- don't reinitialize sstore only if self.cfg is None
    This is not an issue, as the Processor is recycled for every opcode,
    but in general we know that (a) we might need a different type of
    sstore for different opcodes and (b) initializating them is cheap
- recreate sstore when chaining opcodes
    Without this fix chaining an opcode which requires a writable sstore
    to one which doesn't would fail. This doesn't happen today, but it's
    better to fix it anyway

These changes are possible because nowadays all opcodes already require
a working cluster/configuration.

Reviewed-by: iustinp

All the tests there used to creare a cfg, a sstore, an opcode and a LU.
Put all the duplicate code in the setUp function.

Reviewed-by: iustinp

This patch creates a new GanetiContext class, which is used to hold
context common to all ganeti worker threads. As for the
GanetiLockingManager class it is paramount that there is only one such
class throughout the execution of Ganeti, so the class checks for that,
and also forbids its own modification after it's been initialized. The
context for now contains a ConfigWriter and a GanetiLockingManager and
is created by the daemon and propagated to PoolWorker(s) and
JobRunner(s).

Reviewed-by: iustinp

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

In the "new world" we'll need to setup ganeti-noded via ssh on the node
before calling the AddNode opcode. Before doing it we'll check that the
node is not already in the cluster, if --readd was not passed. This
guarantees we're not going to restart ganeti-noded on a running node.

This patch also incidentally fixes a non-style-guide conformant
docstring.

Reviewed-by: iustinp

As we can't use ssh.VerifyNodeHostname directly, we'll set up a mini
node-verify to do checking between the master and the new node. In the
future networking checks, or more nodes, can be added as well.

Reviewed-by: iustinp

Since we're inside a LU we have access to self.sstore.
No need to use ss, which separate instantiation will disappear in a few
patches! ;)

Reviewed-by: iustinp

We used to scp all the ssconf files, and the vnc password file to the
new node. With this patch we use the upload_file rpc, specifying just
the new node as a destination. All the files previously copied by scp
are already allowed by the backend.

Reviewed-by: iustinp

What could possibly go wrong?

Reviewed-by: iustinp

Two LUs are using RunCmd to call fping, in order to check for an IP
presence on the network. Substituting it with TcpPing will get rid of
it, which makes it not break in the new world order, where the master
cannot fork.

Reviewed-by: iustinp

Reviewed-by: iustinp

- s/GanetiQuitException/QuitGanetiException/
- Look for the arguments in err.args, not err itself

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

Having a timestamp on log messages is very useful. The default
format string doesn't include a timestamp.

Reviewed-by: ultrotter