Remove blanket excepts from plugins and lint

This removes most blanket except: clauses from all plugins, including
the base plugin libraries, and bcfg2-lint. The few that remain should
all be necessary.

Most of the changes were quite minor, but this did require some
restructuring of the CfgPrivateKeyCreator; as a result, the tests for
that module were rewritten.

7 files changed, 19 insertions, 21 deletions

diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Apt.py b/src/lib/Bcfg2/Server/Plugins/Packages/Apt.py
index cfabd8457..7de79e2f3 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Apt.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Apt.py
@@ -89,7 +89,7 @@ class AptSource(Source):
                 bprov[barch] = dict()
             try:
                 reader = gzip.GzipFile(fname)
-            except:
+            except IOError:
                 self.logger.error("Packages: Failed to read file %s" % fname)
                 raise
             for line in reader.readlines():
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Pac.py b/src/lib/Bcfg2/Server/Plugins/Packages/Pac.py
index 5f4d2ea41..0e15d2e15 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Pac.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Pac.py
@@ -67,7 +67,7 @@ class PacSource(Source):
             try:
                 self.debug_log("Packages: try to read %s" % fname)
                 tar = tarfile.open(fname, "r")
-            except:
+            except (IOError, tarfile.TarError):
                 self.logger.error("Packages: Failed to read file %s" % fname)
                 raise
 
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Pkgng.py b/src/lib/Bcfg2/Server/Plugins/Packages/Pkgng.py
index e393cabfe..736cdcdd4 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Pkgng.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Pkgng.py
@@ -71,7 +71,7 @@ class PkgngSource(Source):
             try:
                 tar = tarfile.open(fileobj=lzma.LZMAFile(fname))
                 reader = tar.extractfile('packagesite.yaml')
-            except:
+            except (IOError, tarfile.TarError):
                 self.logger.error("Packages: Failed to read file %s" % fname)
                 raise
             for line in reader.readlines():
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Source.py b/src/lib/Bcfg2/Server/Plugins/Packages/Source.py
index 67ada2399..c9f6ea14a 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Source.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Source.py
@@ -331,10 +331,11 @@ class Source(Debuggable):  # pylint: disable=R0902
 
     @track_statistics()
     def setup_data(self, force_update=False):
-        """ Perform all data fetching and setup tasks.  For most
-        backends, this involves downloading all metadata from the
-        repository, parsing it, and caching the parsed data locally.
-        The order of operations is:
+        """Perform all data fetching and setup tasks.
+
+        For most backends, this involves downloading all metadata from
+        the repository, parsing it, and caching the parsed data
+        locally.  The order of operations is:
 
         #. Call :func:`load_state` to try to load data from the local
            cache.
@@ -352,6 +353,15 @@ class Source(Debuggable):  # pylint: disable=R0902
                              upstream repository.
         :type force_update: bool
         """
+        # there are a bunch of wildcard except statements here,
+        # because the various functions called herein (``load_state``,
+        # ``read_files``, ``update``) are defined entirely by the
+        # Packages plugins that implement them.
+        #
+        # TODO: we should define an exception subclass that each of
+        # these functions can raise when an *expected* error condition
+        # is encountered.
+        #
         # pylint: disable=W0702
         if not force_update:
             if os.path.exists(self.cachefile):
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py b/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
index b6e9f13eb..dbe3f9ce5 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/Yum.py
@@ -631,10 +631,6 @@ class YumCollection(Collection):
             err = sys.exc_info()[1]
             self.logger.error("Packages: Could not contact Pulp server: %s" %
                               err)
-        except:
-            err = sys.exc_info()[1]
-            self.logger.error("Packages: Unknown error querying Pulp server: "
-                              "%s" % err)
         return consumer
 
     @track_statistics()
@@ -1034,10 +1030,6 @@ class YumSource(Source):
                 err = sys.exc_info()[1]
                 raise SourceInitError("Could not contact Pulp server: %s" %
                                       err)
-            except:
-                err = sys.exc_info()[1]
-                raise SourceInitError("Unknown error querying Pulp server: %s"
-                                      % err)
             self.rawurl = "%s/%s" % (PULPCONFIG.cds['baseurl'],
                                      self.repo['relative_path'])
             self.arches = [self.repo['arch']]
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py b/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py
index f26d6ba18..b2e43bde7 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/YumHelper.py
@@ -285,8 +285,8 @@ class HelperSubcommand(Bcfg2.Options.Subcommand):
     def run(self, setup):
         try:
             data = json.loads(sys.stdin.read())
-        except:  # pylint: disable=W0702
-            self.logger.error("Unexpected error decoding JSON input: %s" %
+        except ValueError:
+            self.logger.error("Error decoding JSON input: %s" %
                               sys.exc_info()[1])
             print(json.dumps(self.fallback))
             return 2
diff --git a/src/lib/Bcfg2/Server/Plugins/Packages/__init__.py b/src/lib/Bcfg2/Server/Plugins/Packages/__init__.py
index 87d42fd1c..3aa5c415f 100644
--- a/src/lib/Bcfg2/Server/Plugins/Packages/__init__.py
+++ b/src/lib/Bcfg2/Server/Plugins/Packages/__init__.py
@@ -515,10 +515,6 @@ class Packages(Bcfg2.Server.Plugin.Plugin,
                         err = sys.exc_info()[1]
                         self.logger.error("Packages: Error writing %s to %s: "
                                           "%s" % (key, localfile, err))
-                    except:
-                        err = sys.exc_info()[1]
-                        self.logger.error("Packages: Unknown error fetching "
-                                          "%s: %s" % (key, err))
 
         for kfile in glob.glob(os.path.join(self.keypath, "*")):
             if kfile not in keyfiles: