In a previous commit, I accidentially changed the order of
unit tests in Makefile.am to not be alphabetically anymore.
This fixes it.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

This adds functionality to retrieve disk space information
for file storage. It calls the 'df' tool and parses its
output to extract the total and free amount of disk space
on the disk where the given path is located.
The code is not integrated yet, but thoroughly unit-tested.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Bernardo dal Seno <bdalseno@google.com>

The Haskell ConfD client was assuming internet addresses to be IPv4. This
patch modifies the client so that it is able to automatically detect the
protocol it should use by analyzing the address it is told to connect to.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>

This function can be useful to many parts of the code to convert the string
representation of an IP (v4 or v6) address into the proper data type.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Helga Velroyen <helgav@google.com>

Moving 'container.py' to the storage directory.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Renaming the 'block' directory to 'storage', because I plan to
place code there that is related to file storage and leaving
it named 'block' would be misleading.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Renaming 'storage.py' to 'container.py'. It will be moved into the new
'storage' directory, which will come in later patches to avoid clashes of
notation.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

The QA tests the Xen instance status collector, but that is expected to fail
when run on machines that do not use Xen.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

This commit introduces the QA for the instance status collector.

Begin the first QA for a monitoring-related component, the files and some
functions are named after monitoring because they are meant to contain
future monitoring QAs as well.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Some functions for managing instances will have to be used by new upcoming
unit tests, so they are taken out of the instances QA file and put in a new
utilities file accessible by other QA files as well.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Enable the monitoring daemon to invoke the Xen instance status data collector.
Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

The monitoring daemon needs to be able to run some commands that require root
access (such as "xm") in order to fulfill its duties.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

It will need to be accessed by the monitoring daemon.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Add a section related to the new collector.

Also, fix some formatting issue (white spaces, line longer than 80 chars)
in the DRBD collector section.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

The global status is computed from the statuses of the single instances.

The output json format is adapted to include this piece of information, as
prescribed by the design document.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

It will be used by multiple data collectors, not only the DRBD collector.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

The name of the list of instances was not specified.

Also, fix a line that was longer than 80 characters.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Instead of manually specify the name of the data collectors in mon-collector,
just use the dcName field each of them exports.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Instead of building the report as part of the "Main" function, have it
built by its own dedicated function, so that it will be able to export it
directly to the monitoring daemon when needed.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Name, version, format version, category and kind of the Instance Status data
collector are now exported.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Fetch the reason trail from file, failing gracefully if it is not found, and
include it in the output of the instance status data collector.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Added function for determining whether the status of an instance is ok, and to
represent this information in the corresponding field in the report.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Compute the actual state of the instance and export it.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Add the Xen instance status data collector with only its core features.
The next commits will add more reporting functionalities.

The access to the collector is made possible through the mon-collector
tool.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

The Xen instance status data collector will require to get some information
from the hypervisor. This commit introduces a module providing such functions.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

The getInstReasonFilename is built to resemble the python corresponding
function.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

The tests are already using this library, so it's not really a new build
dependency, but it was not specified esplicitly.

Furthermore, it's going to be used by the instance status collector, so it's
added to the requirements for the monitoring subsystem.

Signed-off-by: Michele Tartara <mtartara@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

While this use case was described in the design document, and
mentioned several times as motivation for changes in commit messages,
it has never been added to a user-facing documentation. This commit
adds at least an example to the man page.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

While the multiple-tags test was added to verify that coloring is done
only after node selection (otherwise it wouldn't be possible to get in
both cases a single reboot group), it can easily be extended to also
verify that the correct nodes are selected by --node-tags.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

In the example configuration, the graph constructed by just connecting
primary and secondary instances is two-colorable. However, when taking
conflicting locations of secondary nodes into account, three reboot
groups are needed. Moreover, these reboot groups are not subordinated
to any two-coloring of the first-mentioned graph.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Make hroller take into account the nodes (redundant) instances
will be migrated to. This be behavior can be overridden by the
--offline-maintenance option which will make hroller plan under
the assumption that all instances will be shutdown before starting
with the rolling reboots.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

For online rolling reboots, there are two kind of restrictions. First,
we cannot reboot the primary and secondary nodes of an instance
together. Secondly, two nodes cannot be rebooted simultaneously, if
they are the primary nodes of two instances with the same secondary
node. The second condition requires knowledge of all nodes, not only
those the graph is to be constructed on.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Add a new option to hroller to only output information about the first
reboot group. Together with the option --node-tags this allows for the
following work flow. First tag all nodes; then repeatedly compute the
first node group, handle these nodes and remove the tags. In between
these steps, other operations can be carried out on the cluster.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Make hroller output the node groups not containing the master node
sorted by size, largest group first. The master node still remains
the last node of the last reboot group. In this way, most progress
is made when switching back to normal cluster operations after the
first reboot group.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Thomas Thrainer <thomasth@google.com>

Regular expressions are not shell globs. So "any symbol" is expressed
by a dot, not a question mark. In this case, the confusion lead to a
too liberal expectation, hence the test passed. Fix it nevertheless.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

The order of evaluation of the conditions is changed, so it's easier to add
more (foreseen) checks for exclusive_storage.

Signed-off-by: Bernardo Dal Seno <bdalseno@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Prereq checks relative disks are grouped together and moved in a separate
method. This reduces the clutter in CheckPrereq().

Signed-off-by: Bernardo Dal Seno <bdalseno@google.com>
Reviewed-by: Klaus Aehlig <aehlig@google.com>

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

The example is a cluster of 6 nodes, paired into 3 group by three
instances. So the whole cluster would need two reboot groups. The two
tags select, in two different ways, one node of each group. So, when
restricting to one tag, a single reboot group suffices, but no
coloring of the whole cluster would achieve this.

Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>