We know have a working parseData function that returns the node and
instance data. This uncovered bad support for non-drbd instances ☹️

This patch moves the generic/reusable JSON functions to Utils.hs, so
that they're shared between RAPI/IAlloc.

This will be used in two ways:
  - format the response to Ganeti (easy, implemented)
  - parse the input data and build the node/instance lists (hard :)

This option is the opposite of the --verbose option, and it allows
decreasing the verbosity level from the default of one to zero (which
currently doesn't show the warning messages for missing disk/memory).

This patch moves the oneline format into a separate function for easier
usage.

For clusters with no instances, there is no point in computing either
the score or in running the algorithm. In this case, we exit prematurely
and when running in one-line mode we show dummy information.

This new parameter causes the algorithm to finish (or even not start at
all) if we reach/have a score better than it.

In some case we manually do “if isNothing … then Nothing else …”, which
can be very easily replaced with a monadic construct in the Maybe monad.

It was missing a dependency on the Version.hs file, so right after “make
clean”, a “make dist” used to fail.

Since Xen seems to “steal” some amounts of memory (depending on total
node memory), we increase the maximum allowed missing memory to 512MB,
based on gathered data from multiple machines.

This patch documents the environment variables in the man pages of hbal
and hn1.

This patch adds support for selecting the instance/node file names via
two environment variables (HTOOLS_NODES, HTOOLS_INSTANCES).

Unfortunately we still have lots of duplicated code, since the options
are not unified.

Neither hbal nor hn1 take any arguments beside the options, so if any
are passed is most likely an unintended error. This patch aborts in such
cases.

Use the $HPROGS variable instead of hardcoding the program names.

This patch adds support in hbal for writing the command list to a shell
script, with error checking and allowing for early exit.

Since it's easy to pass a wrong node name as offline, we should abort
instead of silently ignoring it.

This removes most of the content of the README file (obsoleted by new
algorithm and man pages), modifies the Makefile to include the built
documentation in the source archive (so that haddock/hscolour are not
needed) and updates the haddock-prologue with current information.

This moves some data from README to the man pages and has other general
improvements.

This small patch adds disk space checks to the Cluster.checkData
function, and simplifies a little the warning messages.

For Ganeti 1.2 which doesn't have the ‘disk_usage’ instance query field,
we need to manually include the DRBD overhead (per disk). This patch
modifies the RAPI collection to do this, but loading from disk does not
as it's unknown if the query came from hscan or RAPI 1.2 or RAPI 2.0...

This patch adds a man page for hscan and updates the README and other
man pages with the latest changes.

This fixes the setFmem function which didn't compute other related
fields after free memory change. Ideally, this should be abstracted so
that add/remove Pri and similar functions could reuse it instead of
duplicating code.

If an instance is down, it's memory is not reflected in the node used
memory, and thus the node free memory is higher than the actual value.
This patch deducts the memory for such instances from the node free
memory, allowing a correct calculation for such cases.

This patch modifies Rapi, the Cluster.loadData and hscan serialization to load
and save the instance run status. At instance level, we add both a boolean
field denoting the true/false run status, and a string field which holds the
original value (since we don't have a 1-to-1 mapping) for use in hscan
serialization.

The run status is not yet used.

This patch adds checking of cluster data in the binaries and display of
node's x_mem/i_mem in the node list.

This patch adds a checkData function which goes over the node list and computes
the unaccounted memory, returning a list of warning messages (if any) and the
update nodes.

Nodes can have some memory unaccounted for, due to (e.g.) hypervisor
overhead, rounding errors in reporting, etc.

It is better if we model this memory explicitly instead of hiding it,
and actually since the n_mem addition it is actually required to do so.

The new attribute is not yet used.

This patch moves the common CLI functionality (as much as currently
possible) into a separate module. This means we only have one parseOpts
and that Utils.hs doesn't keep this kind of functions anymore.

The Node.str function is very old and is not useful since the node
objects have much more fields today. This patch removes it, and if
needed a full node display can be done via ‘show’.

This patch adds a new n_mem field to the node objects, and implements
read/save/show support for it. The field is not currently used (except
in the node list) but will be used for checking data consistency and
instance up/down status.

This patch changes the parameters passed to the node and instance
constructors from generic Strings (which are then parsed via “read”) to
the actual used types, by converting them earlier in Cluster.loadData.

This fixes a mistake between Int/Integer. Should be more careful :)

This patch adds an hscan tool that loads data from clusters via RAPI and
writes it to files that can be later used offline.

This patch does some small changes:
  - fixes a comment
  - export more node functions (unneeded now, but hscan will use them)
  - fixes Makefile rule for building the programs

This is added for better readability, since this is very often used in
declarations.