This strips the suffix from the objects themselves, not only from the
ktn/kti vars.

This patch makes the format of IAlloc.loadData be similar the same as
Loader.mergeData.

This patch moves the common loading sequence to CLI, such that hbal/hn1
and possible future scripts that take the input from same sources can
use it.

This moves the remaining loading function to Loader (together with its
associated support functions).

This patch generalizes a little the CLI handling by not passing in a
special function for help and such, but instead requiring that the
options object supports some common functionality.

Since both nodes and instances support some common functionality (names
and indices), we add a class so that we can access these attributes in a
generic way.

In order to simplify the data structures, we add back the name on the
node and instance objects. We still keep the index for, well, indexing,
but we will use the name directly from the object, in order to get rid
of the ktn/kti arguments which are passed around everywhere.

This new big patch does a couple of more cleanups in the loading of data
chapter:
  - introduce a Types module that holds most types (except the base
    Node/Instance/etc.) so that multiple other modules can use these
    (instead of only Cluster and its users)
  - bring IAlloc.hs in line with the recent changes of providing data
    types and not strings
  - removal of obsolete Utils.hs json-related functions

This big patch changes the loader model from “string data as common
format” to actual object structures as common format.

The text loading function move from Cluster.hs to a new Text.hs module,
some common functions are moved to a new Loader.hs module, and the
return values from both Rapi.hs and Text.hs are uniformized.

This makes hail compile and get a request parsed via IAlloc, but nothing
more.

This patch adds experimental support to hbal for non-redundant instances
(i.e.  instances with only one node). They are currently handled as
non-moveable, and as such the algorithm simply ignores them.

Supports needs to be added when reading from RAPI via hscan, and
probably in other corner cases.

This patch switches from plain read to a wrapper over readsPrec that
returns better error messages than the buildin 'Prelude: no parse'.

This allows easy checking for valid format of the input data (row-wise).

This patch converts loadTabular and loadData to a monadic form, thus
allowing meaningful error messages from the node/instance load routines.

D'oh, one can extract from a wrapped variable, not only from functions.

This patch changes Cluster.loadData to return a Result, instead of
directly the values; this will allow us to return meaningful error
values (e.g. when an instances lives on unknown node) rather than simply
abort. Currently the result is always an Ok, the actual signalling of
errors will come later.

Its callers are changed to accommodate for the new return type and to
display errors as needed.

This patch adds a very dumb way to override the port and scheme for
RAPI: if the master string doesn't contain a colon, we consider it a
simple hostname specification, and thus prepend ‘https://’ and append
‘:5080’, (the default RAPI port); otherwise, we consider it a fully
specified URL, and don't do any mangling to it.

This allows to use saved RAPI responses in testing, with the “file://”
scheme, or to use another port or non https mode with an actual RAPI
instance.

Now that we dropped 1.2 compatibility, we can removed the special casing
for RAPI differences.

We don't really needed, but is more clean like this.

This big patch converts from our home-grown monad-like constructs
(the Either stuff) to a real, Either-like-but-another-name monad.

We introduce a “Result a” monad, and this allows dropping many of the
extra constructs. Hopefully the code is also more clear.

Many of the functions could now be written in a generic-monad style,
instead of Result specifically, but that will come in future patches.

IAlloc.hs also has some unrelated patches.

Adding a small request type data structure.

This is just a cosmetic (I hope) change; the nodes shouldn't be used
anyway, and we only correct the display message.

Since we only support Ganeti 2.0, we drop the 1.2 compatibility.

This patch drops compatiblity with Ganeti 1.2 and adds support for
offline nodes in the cluster. When reading from RAPI, the drained nodes
are considered offline so that we don't allocate on them too.

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 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.

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 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.

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 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 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.