Bandaid dnf module to temporarily fix some major problems

- Backport config file handling from the DNF module rewrite #527
  (Current config handling does not work with dnf and leads to
  tracebacks when run as an unprivileged user).
- Make a mandatory requirement on yum-utils (for /usr/bin/repoquery)
  because none of the fallback code works for dnf (it's unported yum API
  code).

Both of these issues will be fixed better in the dnf rewrite when it is
feature complete.

Fixes #471

lib/ansible/modules/extras/packaging/os/dnf.py

@@ -99,7 +99,9 @@ options:
 
 notes: []
 # informational: requirements for nodes
-requirements: [ dnf ]
+requirements:
+  - dnf
+  - yum-utils (for repoquery)
 author: '"Cristian van Ee (@DJMuggs)" <cristian at cvee.org>'
 '''
 
@@ -144,18 +146,12 @@ def log(msg):
 def dnf_base(conf_file=None, cachedir=False):
 
     my = dnf.Base()
-    my.logging.verbose_level=0
-    my.logging.verbose_level=0
+    my.conf.debuglevel=0
     if conf_file and os.path.exists(conf_file):
-        my.config = conf_file
-    if cachedir or os.geteuid() != 0:
-     if cachedir or os.geteuid() != 0:
-         if hasattr(my, 'setCacheDir'):
-             my.setCacheDir()
-         else:
-             cachedir = cachedir.dnf.Conf()
-             my.repos.setCacheDir(cachedir)
-             my.conf.cache = 0
+        my.conf.config_file_path = conf_file
+        my.conf.read()
+    my.read_all_repos()
+    my.fill_sack()
 
     return my
 
@@ -164,7 +160,7 @@ def install_dnf_utils(module):
     if not module.check_mode:
         dnf_path = module.get_bin_path('dnf')
         if dnf_path:
-            rc, so, se = module.run_command('%s -y install dnf-plugins-core' % dnf_path)
+            rc, so, se = module.run_command('%s -y install yum-utils' % dnf_path)
             if rc == 0:
                 this_path = module.get_bin_path('repoquery')
                 global repoquery
@@ -819,9 +815,9 @@ def main():
     if params['install_repoquery'] and not repoquery and not module.check_mode:
         install_dnf_utils(module)
 
+    if not repoquery:
+        module.fail_json(msg="repoquery is required to use this module at this time. Please install the yum-utils package.")
     if params['list']:
-        if not repoquery:
-            module.fail_json(msg="repoquery is required to use list= with this module. Please install the dnf-utils package.")
         results = dict(results=list_stuff(module, params['conf_file'], params['list']))
         module.exit_json(**results)