Since all rpc calls were converted, we can now:
  - enforce result type to (status, data)
  - convert all unhandled exceptions to (False, str(err))

This makes sure that all unhandled errors are reported to rpc users.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

We no longer need OS objects to be able to represent invalid OSes. This
cleans up the code handling those cases.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Currently the OSes have a special, customized error handling: the OS
object can represent either a valid OS, or an invalid OS. The associated
function, instead of raising other exception or failing, create custom
OS objects representing failed OSes.

While this was good when no other RPC had failure handling, it's
extremely different from how other function in backend.py expect
failures to be signalled.

This patch reworks this completely:
  - the OS object always represents valid OSes (the next patch will
    remove the valid/invalid field and associated constants)
  - the call_os_diagnose returns instead of a list of OS objects, a list
    of (name, path, status, diagnose_msg); the status is then used in
    cmdlib to determine validity and the status and diagnose_msg values
    are used in gnt-os for display
  - call_os_get returns either a valid OS or a RPC remote failure (with
    the error message)
  - the other functions in backend.py now just call backend.OSFromDisk()
    which will return either a valid OS object or raise an exception
  - the bulk of the OSFromDisk was moved to _TryOSFromDisk which returns
    status, value for the functions which don't want an exception raised

The gnt-os list and diagnose commands still work after this patch.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This patch converts the job queue rpc calls to the new style result.
It's done in a single patch as there are helper function (in both jqueue
and backend) that are used by multiple rpcs and need synchronized
change.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This patch converts all three file-storage rpc (create, delete, rename)
to new style result. This is done in a single patch as they all use a
helper function which itself needs to/can be converted.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This patch converts this rpc into the new style. Since the function
already had some error handling, we remove this custom error reporting
and replace it with our (new-style) result type. This allows significant
cleaning up of this code.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This also converts (and fixes) unittests and mock objects to deal with
this change, and the custom hook verifier in cmdlib.LUClusterVerify.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This also removes custom post-processing from rpc.py; since this call
has only one user, it was simple to move it back to the caller.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This also cleans up its single use in cmdlib.py.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

The patch also adds logging of errors from the ConfigWriter in case the
RPC fails (although today we don't have failure modes).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This was more tricky as the backend function is used by other function
in backend.py. As such, it must be handled specially - it must raise
always an exception and not simply return False, err.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This patch converts this rpc call to the new style result, and also
changes in the process the meaning of the QuitGanetiException's
arguments and the node daemon rpc call exception handler.

The problem with the exception handler is that we used a two-stage one,
and the inner used to catch all exception (including this one), so in
the logs we always had an exception logged, instead of the normal
'leaving cluster message'. The patch also adds logging of the
exception's arguments, so that we have a trail in the logs about the
shutdown mode.

The exception's arguments were reversed from the normal RPC results
style. While it makes somewhat more sense for this exception, we change
them such that they match the rpc result format.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This is used in multiple places outside cmdlib.py, so it's a more
interesting patch.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Only the custom handling in rpc.py for call_node_info used this, so now
it can be removed.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This patch also does some cleanup and enforces valid results (with
proper type, i.e. int for memory/disk values) from remote node,
otherwise we handle the result as failure.

We do this so that we can remove custom processing in rpc.py which is
very old and doesn't play with the new style result (and has bit me by
modifying the result received from the remote node).

After this change, the node_info rpc becomes a normal one.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This should actually have a function in backend, but it's fine for now.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Since backend.GetInstanceList() is used both as RPC endpoint and as
internal function, it can't return (status, value). Instead it returns
only valid instance info, and failures are denoted by exceptions; and
the ganeti-noded function adds the (True,) status.

The patch also fixes a typo.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This changes from a list of booleans to «status, error messages». This
means that instead knowing which disk has failed (position based), we
get a list of all failures (with details how they failed).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This was a very simple (boolean) RPC, so converting it to actually have
more value with the new style results was more difficult.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This doesn't have known failure modes but converting will help later.

We also now call directly utils.ListVolumeGroups() instead of the
backend.ListVolumeGroups() so that we don't have to undo the (status,
value) result type.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This is a big change, because we need to cleanup its users too.

The call and thus LUVerifyDisks LU used to differentiate between failure
at node level and failure at LV level, by returning different types in
the RPC result. This is way too complicated for our needs.

The patch changes to new style result (easy change), and then:
  - changes LUVerifyDisks.Exec() to return a tuple of 3-elements
    instead of 4-elements; we collapse the «nodes not reachable» and
    «nodes with LVM errors» in a single dict
  - changes gnt-cluster to parse 3-element results and simplifies the
    different by-error handling code

Note that the status is added in ganeti-noded, and not in the function
itself, as the function is used in other places too.

This was tested with down nodes and broken VGs.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This converts the export_remove rpc to new style result and also fixes
and old TODO by adding exception handling (and conversion to failure).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This is used in multiple places, so it has a little more changes than
the previous ones.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This also removes some code from ganeti-noded and rpc.py, which should
not do such processing of data (and be simply glue code). (Or
alternatively they could, if we had better infrastructure).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This rpc doesn't have explicit failure modes, but once all RPCs are
converted and we can catch and convert expceptions to failure in noded,
we will have meaningfull error messages.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This also slightly changes the code in cmdlib that uses it for more
clarity.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

These values are deprecated, and not used in 2.1 anymore.
The slots are still there to allow auto-upgrading from 2.0.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>