Reviewed-by: schreiberal

This fixes issue #13.

Reviewed-by: schreiberal

Right now an assembly error produces an exception but not a log message. This
is bad because the exception suggests looking at the log, but the log itself
has a lot of errors which are not really a problem and only some which really
is. In order to make it clear where in the log the problem occurred we log a
message too, before raising the exception.

Reviewed-by: iustinp

Reviewed-by: schreiberal

We want to prevent sending too many 'None' children to a device.
However, the test as it is today is wrong, as we want to test the
situation after adding a new child, and not before. This patch fixes
this by testing greater-or-equal instead of just greater.

Reviewed-by: imsnah

The code assumes all lines have at least two elements which are
whitespace separated - i.e. it does not deal with empty lines or comment
lines with no spaces. This patch fixes this.

Also, the patch replaces the blank between IP and the canonical name
with a tab (restoring previous behaviour).

Reviewed-by: imsnah

This is a critical file. Breaking it would be very bad. Thus, if the system
crashes before the data is synched to the disk, it should have the complete
file afterwards.

Reviewed-by: iustinp

- Combine hostname and aliases on one line
- Fix bug with wrongfully removed newline characters
- Use wrapper for SetEtcHostsEntry in cmdlib

Reviewed-by: iustin

Reviewed-by: TODO

Reviewed-by: schreiberal

In order to make the replace secondary action to be done via the same
opcode parameters for both remote_raid1 and drbd, we must allow the
LUReplaceDisks to change replace_disks_all for drbd with non-empty
remote_node into replace_disks_sec.

This fixes gnt-node evacuate and also allows gnt-instace replace-disks
to have the same syntax for both remote_raid1 and drbd (when replacing
the secondary).

Reviewed-by: ultrotter

Currently, an unreachable node (or one that return undetermined failure)
in the hooks pre-phase will abort the curren operation. This is not
good, as a down node could prevent many operation on the cluster.

This patch changes a RPC-level failure (and not a hook execution
failure) into a warning. It also modifies the related test cases.

This fixes issue 11.

Reviewed-by: ultrotter

Reviewed-by: schreiberal

Reviewed-by: schreiberal

Reviewed-by: schreiberal

This patch modifes:
  - mcpu.Processor.LogWarning to have its 'hint' parameter as optional
    and only log it if not None
  - cmdlib._WaitForSync to not log directly to stdout/stderr but via the
    proc.Log(Info|Warning) methods
  - the LU attribute 'processor' is renamed to 'proc' to shorten the
    name

Reviewed-by: imsnah

This (big) patch does two things:
  - add "local disk status" to the block device checks
    (BlockDevice.GetSyncStatus and the rpc calls that call this
    function, and therefore cmdlib._CheckDiskConsistency)
  - improve the drbd8 secondary replace operation using the above
    functionality

The "local disk status" adds a new variable to the result of
GetSyncStatus that shows the degradation of the local storage of the
device. Of course, not all device support this - for now, we only modify
LogicalVolumes and DRBD8 to return degraded in some cases, other devices
always return non-degraded. This variable should be a subset of
is_degraded - whenever this variable is true, the is_degraded should
also be true.

The drbd8 secondary replace uses this variable as we don't care if the
primary drbd device is network-degraded, only if it has good local disk
data (ldisk is False).

The patch also increases the protocol version (due to rpc changes).

Reviewed-by: imsnah

Reviewed-by: schreiberal

Replace --secondary-node option with an optional parameter for --node.

This patch adds enhanced reporting and much more checks to the disk
replacement (when not switching the secondary).

Reviewed-by: imsnah

Logical volumes can be 'degraded' in a similar way to mirrored devices,
when their underlying storage has gone away (i.e. after a physical disk
failure and 'vgreduce --removemissing'). If we can detect this, we can
prevent mistaken replaces of disks that would use this LV (or its
parent) as source data.

This patch adds support for computing the degraded attribute and
modifies gnt-instance to warn if the LV is virtual.

Reviewed-by: imsnah

Currently, some LUs use logger.Error, others just feedback_fn, etc. This
patch adds three functions to mcpu.Processor than can be used to log
messages to both the log and to the user.

These function will be used to enhance the output of replace-disks for
drbd8 (at least).

Reviewed-by: imsnah

Currently, the mirror operations (add and remove children) test against
the instance's attributes. This patch changes the check tests to work
against the actual status of the device (i.e. live data) which is more
realistic.

The changes are:
  - allow add children if the device doesn't have local storage (even if
    we believe it has)
  - early return from remove children if the device is already without
    local storage

Reviewed-by: imsnah

This patch adds the following functionality:
  - DRBD8 devices can assemble without local storage (done by allowing
    None in the list of children, and making DRBD8 to ignore all
    children if any is None)
  - DRBD8 devices can attach (i.e. identify a device) which is not
    connected to backing storage but to the correct network ports; this
    is a rare case in normal operation (it's what would happen if one
    manually detaches the local disk, and the backing LV still exists)

Reviewed-by: imsnah

This patch enables the bdev.DRBD8 class report a degraded status if the
local disk is missing. This allows `gnt-instance info` to report the
actual situation in this case.

Note that DRBD7 should also behave like this, however the diskless case
is less often met there and we also don't want to change behaviour.

The patch also fixes some docstrings for the GetSyncStatus methods.

Reviewed-by: imsnah

For some cases, we don't have to have access to the children of a device
in order to remove them (e.g. md over lvs, or drbd over lvs). In order
to ease the removal process, skip over finding the child if it provides
a static dev path.

This is needed in order to support removal of children when the
underlying storage has gone away.

Reviewed-by: imsnah

This patch adds a function returning the device path if it is computable
from the disk object (and we don't need to instantiate a bdev object on
the target node in order to compute this). Only LVs support this.

Reviewed-by: imsnah

Reviewed-by: ultrotter

This patch adds a check in the prereq of LUInitCluster for the existence
of the init script.  This allows a clean abort instead of a stack dump.

Based on a report by admin@steibei.net

Reviewed-by: ultrotter

The block device creation process is the following:
  - device create
  - device assembly (on primary or depending on dev_type, on secondary
    too)
  - set sync speed
  - return

The problem is that device assembly after creation was not checked for
errors, and as this is a very unusual case, we did not have problems
with it (or we didn't detect them). The recent DevCacheManager however
tripped on this case (because the dev_path of the device is None if the
assembly fails) and the creation aborted with an unclear error message.

The patch adds a check for the assembly success and aborts the creation
of the device in this case - the error is quite clear in the instance
add, for example. The patch also changes DevCacheManager to log the
cases when dev_path is None but not raise an error (keeping consistent
with the goal that the cache manager should be transparent to the code).

For the record, this error case was detected with a mismatch between
drbd kernel module and utilities.

Reviewed-by: imsnah

This patch fixes some minor pylint warnings (unused variables, wrong
indentation, etc.) and a real bug in the recovery for drbd8 rename
procedure.

Reviewed-by: imsnah

Reviewed-by: schreiberal

The OS cleanup patches change the wire protocol. Increment the protocol number
by one.

Reviewed-By: iustinp

In order to do this for simplicity we leave the OSFromDisk function as-is and
we convert the eventual exception to an OS object in ganeti-noded. The
unmangling gets simplified and so does the code for checking whether the OS is
valid.

Reviewed-By: iustinp

The functions in ganeti-noded and rpc.py still deal with the fact that an
InvalidOS error could be returned by DiagnoseOS. As this is not the case
anymore simplify their code for the current behavior.

Reviewed-By: iustinp

Modify backend.py so that DiagnoseOS only returns OS objects rather than
InvalidOS errors, and make sure gnt-os understands the new objects. Also delete
the deprecated helper functions from gnt-os.

Reviewed-By: iustinp

Add a new FromInvalidOS static function to objects.OS that makes it easy to
create an object representing a broken OS starting from the relevant exception.

Reviewed-By: iustinp

Till now the OS object just represents a correct OS instance.  Change it so it
can represent a broken one too, by adding a "status" field: if this field is
different from the OS_VALID_STATUS constant the object is considered to be an
invalid OS, the "status" field to be a debugging message, and its boolean
status is set to false.

Reviewed-By: iustinp

call_os_get is never called with a real list of nodes, so there's no point in
it being multi-node. Making it single-node till a usage for multi-node call is
found.

Reviewed-By: iustinp