Add a BrewPreBuiltBuilder.

Allows you to use pre-submitted brew builds as if they were generated
locally. Build *must* have been submitted to brew beforehand, otherwise
this will fail.

src/tito/builder.py

@@ -876,7 +876,7 @@ class MockBuilder(Builder):
 
         # Copy everything mock wrote out to /tmp/tito:
         files = os.listdir(mock_output_dir)
-        run_command("cp %s/*.rpm %s" %
+        run_command("cp -v %s/*.rpm %s" %
                 (mock_output_dir, self.rpmbuild_basedir))
         print
         print("Wrote:")
@@ -885,3 +885,58 @@ class MockBuilder(Builder):
             print("  %s" % rpm_path)
             self.artifacts.append(rpm_path)
         print
+
+
+class BrewPreBuiltBuilder(Builder):
+    """
+    A special case builder which uses pre-existing Brew builds and
+    pulls down the resulting rpms locally. Useful in some cases when
+    generating yum repositories during a release.
+    """
+    REQUIRED_ARGS = ['disttag']
+
+    def __init__(self, name=None, version=None, tag=None, build_dir=None,
+            pkg_config=None, global_config=None, user_config=None,
+            options=None, args=None):
+
+        Builder.__init__(self, name=name, version=version, tag=tag,
+                build_dir=build_dir, pkg_config=pkg_config,
+                global_config=global_config, user_config=user_config,
+                options=options, args=args)
+
+        self.brew_tag = 'meow' #args['brewtag']
+        self.dist_tag = args['disttag']
+
+    def _rpm(self):
+        """
+        Uses the SRPM
+        Override the base builder rpm method.
+        """
+
+        print("Fetching rpms for %s.%s from brew:" % (
+            self.build_tag, self.dist_tag))
+        self._fetch_from_brew()
+
+    def _fetch_from_brew(self):
+        brew_nvr = "%s.%s" % (self.build_tag, self.dist_tag)
+        debug("Brew NVR: %s" % brew_nvr)
+        os.chdir(self.rpmbuild_dir)
+        run_command("brew download-build %s" % brew_nvr)
+
+        # Wipe out the src rpm for now:
+        run_command("rm *.src.rpm")
+
+        # Copy everything brew downloaded out to /tmp/tito:
+        files = os.listdir(self.rpmbuild_dir)
+        run_command("cp -v %s/*.rpm %s" %
+                (self.rpmbuild_dir, self.rpmbuild_basedir))
+        print
+        print("Wrote:")
+        for rpm in files:
+            # Just incase anything slips into the build dir:
+            if not rpm.endswith(".rpm"):
+                continue
+            rpm_path = os.path.join(self.rpmbuild_basedir, rpm)
+            print("  %s" % rpm_path)
+            self.artifacts.append(rpm_path)
+        print