Support for koji profiles.

This patch is dmach's patch [1] refactored according to mikem's comments [2].

[1] https://lists.fedoraproject.org/pipermail/buildsys/2015-August/004857.html
[2] https://lists.fedoraproject.org/pipermail/buildsys/2015-October/004900.html

Signed-off-by: Tomas Mlcoch <tmlcoch@redhat.com>

docs/profiles.rst

@@ -0,0 +1,74 @@
+=============
+Koji Profiles
+=============
+This document describes how to work with koji profiles.
+
+
+Command Line Interface
+======================
+Koji client allows connecting to multiple koji instances from CLI
+by using profiles. The default profile is given by executable file name,
+which is 'koji'.
+
+To change koji profile, you can:
+
+ * run koji with --profile=$profile_name argument
+ * change executable file name by symlinking $profile_name -> koji
+
+
+Configuration Files
+===================
+Configuration files are located in following locations:
+
+ * /etc/koji.conf
+ * /etc/koji.conf.d/\*.conf
+ * ~/.koji/config.d/\*.conf
+ * user-specified config
+
+Koji reads them, looking for [$profile_name] sections.
+
+
+Using Koji Profiles in Python
+=============================
+Instead of using koji module directly,
+get profile specific module by calling::
+
+    >>> mod = koji.get_profile_module($profile_name)
+
+This module is clone of koji module with additional
+profile specific tweaks.
+
+Profile configuration is available via::
+
+    >>> mod.config
+
+
+Example
+-------
+
+Print configuration::
+
+    import koji
+
+    fedora_koji = koji.get_profile_module("koji")
+    ppc_koji = koji.get_profile_module("ppc-koji")
+
+    for i in (fedora_koji, ppc_koji):
+        print "PROFILE: %s" % i.config.profile
+        for key, value in sorted(i.config.__dict__.items()):
+            print "    %s = %s" % (key, value)
+        print
+
+
+Use ClientSession::
+
+    import koji
+
+    koji_module = koji.get_profile_module("koji")
+    client = koji_module.ClientSession(koji_module.config.server)
+    print client.listTags()
+
+
+TODO
+====
+* consider using pyxdg for user config locations

koji/__init__.py

@@ -34,6 +34,7 @@ import errno
 import exceptions
 from fnmatch import fnmatch
 import httplib
+import imp
 import logging
 import logging.handlers
 from koji.util import md5_constructor
@@ -63,6 +64,8 @@ import xml.sax.handler
 from xmlrpclib import loads, dumps, Fault
 import zipfile
 
+PROFILE_MODULES = {}  # {module_name: module_instance}
+
 def _(args):
     """Stub function for translation"""
     return args  # pragma: no cover
@@ -1551,6 +1554,49 @@ def read_config(profile_name, user_config=None):
     return result
 
 
+def get_profile_module(profile_name, config=None):
+    """
+    Create module for a koji instance.
+    Override profile specific module attributes:
+     * BASEDIR
+     * config
+     * pathinfo
+
+    profile_name is str with name of the profile
+    config is instance of optparse.Values()
+    """
+    global PROFILE_MODULES  # Dict with loaded modules
+
+    # If config is passed use it and don't load koji config files by yourself
+    if config is None:
+        result = read_config(profile_name)
+        config = optparse.Values(result)
+
+    # Prepare module name
+    mod_name = "__%s__%s" % (__name__, profile_name)
+
+    # Check if profile module exists and if so return it
+    if mod_name in PROFILE_MODULES:
+        return PROFILE_MODULES[mod_name]
+
+    # Load current module under a new name
+    koji_module_loc = imp.find_module(__name__)
+    mod = imp.load_module(mod_name,
+                          None,
+                          koji_module_loc[1],
+                          koji_module_loc[2])
+
+    # Tweak config of the new module
+    mod.config = config
+    mod.BASEDIR = config.topdir
+    mod.pathinfo.topdir = config.topdir
+
+    # Be sure that get_profile_module is only called from main module
+    mod.get_profile_module = get_profile_module
+
+    return mod
+
+
 class PathInfo(object):
     # ASCII numbers and upper- and lower-case letter for use in tmpdir()
     ASCII_CHARS = [chr(i) for i in range(48, 58) + range(65, 91) + range(97, 123)]