Testing with a newer hlint found a few minor issues; but all are real,
valid recommendations:

- don't use "if cond then f x else f y", but "f (if cond then x else y)"
- "if a then b else True" is equivalent to the simpler "not a || b"
- and as usual, one more ignore to our "testing basic properties"
  module

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This follows a conversation we had for how to deal with
optional-but-required fields in JSON serialisations: fields which are
optional (can be either a given type or 'null'), but where the 'null'
value is required. There are just a few of these in the Python code,
but we should support them nevertheless.

The patch changes the 'isOptional' attribute from boolean to a custom
ADT, three-typed. This allows us to keep the same path on load (which
deals with both cases), but use a custom save path where we explicitly
save the 'null' value.

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

Change {exp,act}Code to {exp,act}Ver, which gives a better idea that
the integer fields represent version numbers.

Also:

  - errors.py: update OpPrereqError's docstring to note that an error
    code is always expected as the second argument (it was previously
    optional).

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

The isOptional function is no longer used after a1505857 (“Convert
opcode TH code to the use of Field type”).

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

This patch converts all the call paths from 'Result' (which contains
just string errors) to 'ErrorResult', which holds
GanetiException-encoded errors. We can now return proper
OpPrereq/OpExec errors to the clients of the luxi/query socket.

The patch touches many files as we had to convert the entire call
chains in a single round. But it should be pretty straightforward
otherwise:

- change 'Result' into 'ErrorResult'
- add error annotations: change "Bad msg" into "Bad (XXXEror msg)"
- add a helper function for confd, where we don't send to client
  formatted exceptions, to convert back from ErrorResult into Result
- change tests similarly, where needed

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

In Python, formatError also returns the exit code, but I find that
splitting them leads to clearer code.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

As described in the module doc string, while writing this it dawned
upon me that we're mixing all errors together into a single hierarchy
(well, type on the Haskell side), which is not good. Some errors are
used purely within noded, some in the CLI frontends, etc. so these
should not be the same type; frontend functions should only be able to
raise frontend errors, not backend ones.

As to this patch itself, I've used again Template Haskell to generate
both the data type and the serialisation functions, as the initial
version, hand-written, seemed too prone to errors due to string
matching.

A small unittest for checking serialisation consistency is also added.

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

These are almost generic, so let's change the signatures a bit a make
them fully so.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Adeodato Simo <dato@google.com>

This 'simple' way of defining objects will be used also for errors, so
let's make it less Luxi-specific.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This patch includes:

* The 'failN1' flag is now only set if there is strictly less
  memory available than required for failover.
* Unit tests for that.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Small simplifications of other unit tests using the (==?)
operator when possible, and typo fixes.

Signed-off-by: Helga Velroyen <helgav@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

eitherToResult now converts from `Either a b` to `GenericResult`, not
necessarily from `Either String` only. Also, fix a typo.

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Since we now have the GeneralResult as a multi-purpose monad, we can
remove the custom OpResult monad, and just use 'GeneralResult
FailMode' as our type. This allows removal of a few bits of
specialised infrastructure, relying instead on the generic one.

The restriction on using OpResult as a general monad remains as
before.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Furthermore, a few messages have their capitalisation changed (fixed).

Signed-off-by: Helga Velroyen <helgav@google.com>
Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Currently, our error monad—Result—has a plain string error type. This
is not good, as we don't have structured errors, we can't pass back
proper error information to Python code, etc.

To solve this, we generalise this type as 'GenericResult a', and make
Result an alias to 'GenericResult String' for compatibility with the
old code. New error hierarchies will be introduced as different
types. Furthermore, we generalise our helper functions too, so that
they can work on any 'GeneralInstance a' type, not only Result.

There are two small drawbacks to this generalisation. First, a Monad
instance requires (at least for the way we use it) a 'fail :: String
-> m a' instance, so we need to be able to build an 'a' value from a
string; therefore, we can implement the Monad instance only for a
newly-introduced typeclass, 'FromString', which requires the needed
conversion function. Second, due to the fact that 'String' is a type
alias (for [Char]) instead of an actual type, we need to enable the
FlexibleInstances language pragma; as far as I know, this has no
significant drawbacks.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This commit adds a Group.allTags field to store the tags of node groups,
and teaches each loader backend in HTools to populate it (additionally, the
IAllocator class in lib/cmdlib.py now includes tags for groups too). Test
data is updated to include an empty set of tags for node groups in all
affected test cases.

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

The mergeData function in Loader.hs included a step to filter an instance's
tags to include only the exclusion tags (as specified via the commandline,
or cluster-level tags). Later on, code in Node.hs assumed Instance.tags to
contain only tags to be used for exclusion.

Because in the future we will need to access the full list of an instance's
tags (and not only exclusion tags), this commits deprecates the 'tags'
field, and introduces Instance.exclTags and Instance.allTags.

Instance.allTags is now populated from the different backends (Text, Luxi,
Rapi, etc.), and Instance.exclTags is only populated from Loader.mergeData,
as was done previously. This means that loading tags from e.g. Text or Simu
and assuming that they'll be used as exclusion tags without going through
Loader.hs will no longer work; but this was already the case with other
fields, and 'mergeData' or 'loadExternalData' continue to be the only entry
points to get a consistent view of the cluster. (Additionally, there were
no tests that made this assumption that I could find.)

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

This only supports test delay for now, is not built by default (only
on demand), and is also not installed anywhere.

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

Also add some more haddock structure to the module. The RPC call
itself is rather trivial.

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

By accident, we sent the node object as call data in this rpc call,
instead the version request (i.e. nothing). This is due to the fact
that the 'call' data comes second, not first in the function argument.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

Before we reorganised the source tree, the 'Result' type was exported
from HTools/Types.hs. This changed during the reorg, but at that time
we didn't change the exports; instead, we kept re-exporting it from
the old module for compatibility.

In light of future changes to the Result type, let's stop this
re-export and cleanup the imports of the other modules.

One test is slightly rewritten with explicit types declaration (part
of the values already needed one, let's make it explicit).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

The comments in parseData had become out of date with the implementations
of load{Group,Node,Inst}. This commit updates the field list in comments to
match the implementations.

Signed-off-by: Dato Simó <dato@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

While grepping for htools imports in the non-htools subdirectory, I
saw that our haddock prologue and title are very very old and refer to
the old htools-only state. Let's cleanup a bit…

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This patch removes the last HTools module imports from non-htools code
(the HTools.Types module), but it requires an associated cleanup:
using luxi-specific constants for luxi timeouts (the only effect is
that one timeout decreases from 15 to 10, the default value in the
python code), and moving of the (now) RAPI specific constants to
RAPI.hs (which allows simplifying their type/usage).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

… and also use it to simplify 'needsLiveData'. Additionally, add an
explicit export list to Ganeti.Query.Types, since otherwise we'd
(re)export all imported symbols.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

This patch adds support for classic-style queries (before query2) to
the query socket server. The patch is rather trivial, since as in
Python we just piggy-back on the query2 implementation.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

And associated unittests. This will be needed for classic-style
queries.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

When initially implementing the node query, I thought the 'powered'
field is a representation of the run-time powered status, which would
make its query complex.

In reality, it's a simple config query, which we can support
easily. We also add a small helper, so that we don't hardcode the
RSUnavail case in many places.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

We don't add a type class for fully-generic handling, but we do
abstract the duplicate part.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

… and use it in the Query implementation, removing the last
non-correct query field for Groups.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This makes the "all" names queries consistent with the Python
results. The change requires updating the unittests, at which point a
duplicate error message is simplified.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

We do this not quite generically, which means we have to add
another layer in the call chain, and rename the current query
function, plus add special-case code for each query type. Hopefully we
will be able to improve on this in the future.

A (good) side effect of this patch is that we get the desired
ordering when names are requested, matching the Python code.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

This replicates in the Haskell Query2 implementation the behaviour of
the Python code: if a "simple" filter is passed (one that contains
only Or aggregators  and EQ binary ops on the name field), then an
failure is flagged if the given values are not known.

Our implementation is pretty straightforward, with a few details:

- we ignore any NumericValues passed, since that inconsistency will be
  flagged by the filter compiler
- we return an the non-normalized names from the getRequestedNames
  function, and not the fully-normalized ones; this will be done later
  in individual query functions
- we test a few of the desired behaviours of the above-mentioned
  function

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

The disk free/total values are optional ones, wrapped in a Maybe, so
we shouldn't directly serialise them. In order to simplify the
embedded extraction, we add a small helper function.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

We need to only query the default (first enabled) hypervisor, not all
hypervisors. For this, we need to add a manual check to ensure that we
don't have a corrupt config (there's no "NonEmptyList" type…).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

The String parameter to 'nodeLiveFieldExtract' is the query2 field
name, not the RPC-layer field name. Grrr for not having a real data
type for this.

Furthermore, we add some safety check that we don't return JSNull via
rsNormal…

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Agata Murawska <agatamurawska@google.com>

This patch makes regex-pcre optional, allowing its disable via a
preprocessor define NO_REGEX_PCRE. This define will be added to
config.ac/Makefile.am in the next patch.

The patch also changes multi-line strings into string concatenation,
due to limitations with the CPP language extension.

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

This patch adds a NiceSort equivalent and the corresponding unittest
(partially copied from Python unittest). The difference between the
Python version and this one is that this implementation doesn't use
regular expressions, and as such it doesn't have the 8-groups
limitation.

The key-based version is separate from the non-key one (since we don't
have default arguments in Haskell), and is tested less in its absolute
properties but only that it is identical to the non-key version under
some transformations (the non-key version is much more tested).

This will be needed later in query name sorting.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This allows the command completion to treat them as separate option
types; this is not useful in build-bash-completion right now, but
might become so in the future.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This defines the arguments supported and then modifies the
--help-completion output to include them too.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>