Ticket #2850 - Ipactl exception not handled well

There were various places in ipactl which intialized IpactlError with
None as the msg. If you called str() on that exception all was well
because ScriptError.__str__() converted a msg with None to the empty
string (IpactlError is subclassed from ScriptError). But a few places
directly access e.msg which will be None if initialized that way. It's
hard to tell from the stack traces but I'm pretty sure it's those
places which use e.msg directly which will cause the problems seen in
the bug report.

I do not believe it is ever correct to initialize an exception message
to None, I don't even understand what that means. On the other hand
initializing to the empty string is sensible and for that matter is
the default for the class.

This patch makes two fixes:

1) The ScriptError initializer will now convert a msg parameter of
None to the empty string.

2) All places that initialized IpactlError's msg parameter to None
removed the None initializer allowing the msg parameter to default
to the empty string.

I don't know how to test the fix for Ticket #2850 because it's not
clear how it got into that state in the first place, but I do believe
initialing the msg value to None is clearly wrong and should fix the
problem.

Because the attrs & values in DN's, RDN's and AVA's are comparison case-
insensitive the hash value between two objects which compare as equal but
differ in case must also yield the same hash value. This is critical when
these objects are used as a dict key or in a set because dicts and sets
use the object's __hash__ value in conjunction with the objects __eq__
method to lookup the object.

The defect is the DN, RDN & AVA objects computed their hash from the case-
preserving string representation thus two otherwise equal objects
incorrectly yielded different hash values.

The problem manifests itself when one of these objects is used as a key in
a dict, for example a dn.

dn1 = DN(('cn', 'Bob'))
dn2 = DN(('cn', 'bob'))

dn1 == dn2 --> True

hash(dn1) == hash(dn2) --> False

d = {}

d[dn1] = x
d[dn2] = y

len(d) --> 2

The patch fixes the above by lower casing the string representation of
the object prior to computing it's hash.

The patch also corrects a spelling mistake and a bogus return value in
ldapupdate.py which happened to be discovered while researching this
bug.

Due to recent addition of ID range support to DsInstance, the class
could no longer be instantiated when realm_name was passed but
ID range parameters were not. This condition broke winsync agreements
creation in ipa-replica-manage.

Make sure that ID range computation in DsInstance does not crash in
this cases so that winsync replica can be created. Also convert --binddn
option of ipa-replica-manage script to IPA native DN type so that
setup_agreement does not crash.

https://fedorahosted.org/freeipa/ticket/2987

* Convert every string specifying a DN into a DN object

* Every place a dn was manipulated in some fashion it was replaced by
  the use of DN operators

* Add new DNParam parameter type for parameters which are DN's

* DN objects are used 100% of the time throughout the entire data
  pipeline whenever something is logically a dn.

* Many classes now enforce DN usage for their attributes which are
  dn's. This is implmented via ipautil.dn_attribute_property(). The
  only permitted types for a class attribute specified to be a DN are
  either None or a DN object.

* Require that every place a dn is used it must be a DN object.
  This translates into lot of::

    assert isinstance(dn, DN)

  sprinkled through out the code. Maintaining these asserts is
  valuable to preserve DN type enforcement. The asserts can be
  disabled in production.

  The goal of 100% DN usage 100% of the time has been realized, these
  asserts are meant to preserve that.

  The asserts also proved valuable in detecting functions which did
  not obey their function signatures, such as the baseldap pre and
  post callbacks.

* Moved ipalib.dn to ipapython.dn because DN class is shared with all
  components, not just the server which uses ipalib.

* All API's now accept DN's natively, no need to convert to str (or
  unicode).

* Removed ipalib.encoder and encode/decode decorators. Type conversion
  is now explicitly performed in each IPASimpleLDAPObject method which
  emulates a ldap.SimpleLDAPObject method.

* Entity & Entry classes now utilize DN's

* Removed __getattr__ in Entity & Entity clases. There were two
  problems with it. It presented synthetic Python object attributes
  based on the current LDAP data it contained. There is no way to
  validate synthetic attributes using code checkers, you can't search
  the code to find LDAP attribute accesses (because synthetic
  attriutes look like Python attributes instead of LDAP data) and
  error handling is circumscribed. Secondly __getattr__ was hiding
  Python internal methods which broke class semantics.

* Replace use of methods inherited from ldap.SimpleLDAPObject via
  IPAdmin class with IPAdmin methods. Directly using inherited methods
  was causing us to bypass IPA logic. Mostly this meant replacing the
  use of search_s() with getEntry() or getList(). Similarly direct
  access of the LDAP data in classes using IPAdmin were replaced with
  calls to getValue() or getValues().

* Objects returned by ldap2.find_entries() are now compatible with
  either the python-ldap access methodology or the Entity/Entry access
  methodology.

* All ldap operations now funnel through the common
  IPASimpleLDAPObject giving us a single location where we interface
  to python-ldap and perform conversions.

* The above 4 modifications means we've greatly reduced the
  proliferation of multiple inconsistent ways to perform LDAP
  operations. We are well on the way to having a single API in IPA for
  doing LDAP (a long range goal).

* All certificate subject bases are now DN's

* DN objects were enhanced thusly:
  - find, rfind, index, rindex, replace and insert methods were added
  - AVA, RDN and DN classes were refactored in immutable and mutable
    variants, the mutable variants are EditableAVA, EditableRDN and
    EditableDN. By default we use the immutable variants preserving
    important semantics. To edit a DN cast it to an EditableDN and
    cast it back to DN when done editing. These issues are fully
    described in other documentation.
  - first_key_match was removed
  - DN equalty comparison permits comparison to a basestring

* Fixed ldapupdate to work with DN's. This work included:
  - Enhance test_updates.py to do more checking after applying
    update. Add test for update_from_dict(). Convert code to use
    unittest classes.
  - Consolidated duplicate code.
  - Moved code which should have been in the class into the class.
  - Fix the handling of the 'deleteentry' update action. It's no longer
    necessary to supply fake attributes to make it work. Detect case
    where subsequent update applies a change to entry previously marked
    for deletetion. General clean-up and simplification of the
    'deleteentry' logic.
  - Rewrote a couple of functions to be clearer and more Pythonic.
  - Added documentation on the data structure being used.
  - Simplfy the use of update_from_dict()

* Removed all usage of get_schema() which was being called prior to
  accessing the .schema attribute of an object. If a class is using
  internal lazy loading as an optimization it's not right to require
  users of the interface to be aware of internal
  optimization's. schema is now a property and when the schema
  property is accessed it calls a private internal method to perform
  the lazy loading.

* Added SchemaCache class to cache the schema's from individual
  servers. This was done because of the observation we talk to
  different LDAP servers, each of which may have it's own
  schema. Previously we globally cached the schema from the first
  server we connected to and returned that schema in all contexts. The
  cache includes controls to invalidate it thus forcing a schema
  refresh.

* Schema caching is now senstive to the run time context. During
  install and upgrade the schema can change leading to errors due to
  out-of-date cached schema. The schema cache is refreshed in these
  contexts.

* We are aware of the LDAP syntax of all LDAP attributes. Every
  attribute returned from an LDAP operation is passed through a
  central table look-up based on it's LDAP syntax. The table key is
  the LDAP syntax it's value is a Python callable that returns a
  Python object matching the LDAP syntax. There are a handful of LDAP
  attributes whose syntax is historically incorrect
  (e.g. DistguishedNames that are defined as DirectoryStrings). The
  table driven conversion mechanism is augmented with a table of
  hard coded exceptions.

  Currently only the following conversions occur via the table:

  - dn's are converted to DN objects

  - binary objects are converted to Python str objects (IPA
    convention).

  - everything else is converted to unicode using UTF-8 decoding (IPA
    convention).

  However, now that the table driven conversion mechanism is in place
  it would be trivial to do things such as converting attributes
  which have LDAP integer syntax into a Python integer, etc.

* Expected values in the unit tests which are a DN no longer need to
  use lambda expressions to promote the returned value to a DN for
  equality comparison. The return value is automatically promoted to
  a DN. The lambda expressions have been removed making the code much
  simpler and easier to read.

* Add class level logging to a number of classes which did not support
  logging, less need for use of root_logger.

* Remove ipaserver/conn.py, it was unused.

* Consolidated duplicate code wherever it was found.

* Fixed many places that used string concatenation to form a new
  string rather than string formatting operators. This is necessary
  because string formatting converts it's arguments to a string prior
  to building the result string. You can't concatenate a string and a
  non-string.

* Simplify logic in rename_managed plugin. Use DN operators to edit
  dn's.

* The live version of ipa-ldap-updater did not generate a log file.
  The offline version did, now both do.

https://fedorahosted.org/freeipa/ticket/1670
https://fedorahosted.org/freeipa/ticket/1671
https://fedorahosted.org/freeipa/ticket/1672
https://fedorahosted.org/freeipa/ticket/1673
https://fedorahosted.org/freeipa/ticket/1674
https://fedorahosted.org/freeipa/ticket/1392
https://fedorahosted.org/freeipa/ticket/2872

When the --hostname option is given to ipa-client-install, we
write HOSTNAME to /etc/sysconfig/network. When that file didn't exist,
the installer crashed.

Create the file if it doesn't exist and we need to write to it.

https://fedorahosted.org/freeipa/ticket/2840

A change to ipa-ldap-updater (and thus an RPM update %post scriptlet)
avoiding redundat "IPA is not configured" message in stderr introdocued
in c20d4c71b87365b3b8d9c53418a79f992e68cd00 was reverted in another
patch (b5c1ce88a4a3b35adb3b22bc68fb10b49322641a).

Return the change back to avoid this message during every RPM update
when IPA is not configured. admintool framework was also fixed to
avoid print an empty line when an exception without an error message
is raised.

https://fedorahosted.org/freeipa/ticket/2892

Certificate renewal can be done only one one CA as the certificates need
to be shared amongst them. certmonger has been trained to communicate
directly with dogtag to perform the renewals. The initial CA installation
is the defacto certificate renewal master.

A copy of the certificate is stored in the IPA LDAP tree in
cn=ca_renewal,cn=ipa,cn=etc,$SUFFIX, the rdn being the nickname of the
certificate, when a certificate is renewed. Only the most current
certificate is stored. It is valid to have no certificates there, it means
that no renewals have taken place.

The clones are configured with a new certmonger CA type that polls this
location in the IPA tree looking for an updated certificate. If one is
not found then certmonger is put into the CA_WORKING state and will poll
every 8 hours until an updated certificate is available.

The RA agent certificate, ipaCert in /etc/httpd/alias, is a special case.
When this certificate is updated we also need to update its entry in
the dogtag tree, adding the updated certificate and telling dogtag which
certificate to use. This is the certificate that lets IPA issue
certificates.

On upgrades we check to see if the certificate tracking is already in
place. If not then we need to determine if this is the master that will
do the renewals or not. This decision is made based on whether it was
the first master installed. It is concievable that this master is no
longer available meaning that none are actually tracking renewal. We
will need to document this.

https://fedorahosted.org/freeipa/ticket/2803

Currently, FreeIPA's install/admin scripts are long pieces of code
that aren't very reusable, importable, or testable.
They have been extended over time with features such as logging and
error handling, but since each tool was extended individually, there
is much inconsistency and code duplication.
This patch starts a framework which the admin tools can use, and
converts ipa-ldap-updater to use the framework.

Common tasks the tools do -- option parsing, validation, logging
setup, error handling -- are represented as methods. Individual
tools can extend, override or reuse the defaults as they see fit.

The ipa-ldap-updater has two modes (normal and --upgrade) that
don't share much functionality. They are represented by separate
classes. Option parsing, and selecting which class to run, happens
before they're instantiated.

All code is moved to importable modules to aid future testing. The
only thing that remains in the ipa-ldap-updater script is a two-line
call to the library.

First part of the work for:
https://fedorahosted.org/freeipa/ticket/2652

Many functions use low-level socket interface for connection or
various checks. However, most of the time we don't respect
automatic address family detection but rather try to force our
values. This may cause either redundat connection tries when an
address family is disabled on system tries or even crashes
when socket exceptions are not properly caught.

Instead of forcing address families to socket, rather use
getaddrinfo interface to automatically retrieve a list of all
relevant address families and other connection settings when
connecting to remote/local machine or binding to a local port.
Now, we will also fill correctly all connection parameters like
flowinfo and scopeid for IPv6 connections which will for example
prevent issues with scoped IPv6 addresses.

bind_port_responder function was changed to at first try to bind
to IPv6 wildcard address before IPv4 as IPv6 socket is able to
accept both IPv4 and IPv6 connections (unlike IPv4 socket).

nsslib connection was refactored to use nss.io.AddrInfo class to
get all the available connections. Socket is now not created by
default in NSSConnection class initializer, but rather when the
actual connection is being made, becase we do not an address family
where connection is successful.

https://fedorahosted.org/freeipa/ticket/2913
https://fedorahosted.org/freeipa/ticket/2695

All service start/restart currently go through ipapython/platform so
move the "wait for service to start" code there as well.

A dictionary of known services and ports to wait on is defined in base.py
This is referenced by the platforms by instance name to determine what
to wait for. For the case of dirsrv if we get that as a plain name
(no specific instance) it is assumed to be the main IPA service.

https://fedorahosted.org/freeipa/ticket/2375
https://fedorahosted.org/freeipa/ticket/2610