lint: add colors for better readability

Errors are highlighted in red, warnings in yellow, and success in green.

First word of lint message is printed in bold as it's usually the error
name.

This makes parsing lint output much easier/faster \o/

Note: Colors are disabled for non-interactive stdout by default.

Related: #115

Change-Id: I51cc66c089cea79d893e2e833dfb5e6fa4e16c55

rdopkg/utils/lint.py

@@ -21,6 +21,22 @@ def __repr__(self):
         return ('%s: %s: %s' %
                 (self.location, self.level, self.msg))
 
+    def pretty_str(self):
+        fmt = "{loc}: {t.%s}{lvl}{t.normal}: {t.bold}{msg1}{t.normal} {msg2}"
+        if self.level == 'W':
+            color = 'yellow'
+        else:
+            color = 'red'
+        fmt = fmt % color
+        msg1, _, msg2 = self.msg.partition(' ')
+        return fmt.format(
+            loc=self.location,
+            lvl=self.level,
+            msg1=msg1,
+            msg2=msg2,
+            t=log.term
+        )
+
 
 RE_RPMLINT_HINT = r'(.*):\s+([EW]):\s+(.+)$'
 RE_RPMLINT_SUMMARY = (r'\d+ packages and \d+ specfiles checked; '
@@ -76,7 +92,7 @@ def sanity_check_buildarch(txt):
 
 def sanity_check_patches_base(txt):
     # duplicate patches_base might lead to unexpected behavior
-    bases = re.findall('^#\s*patches_base', txt, flags=re.M)
+    bases = re.findall(r'^#\s*patches_base', txt, flags=re.M)
     if len(bases) > 1:
         return False
     return True
@@ -96,8 +112,8 @@ def sanity_check(spec_fn):
             "buildarch-before-sources: Due to mysterious"
             "ways of rpm, BuildArch needs to be placed "
             "AFTER SourceX and PatchX lines in .spec file, "
-            "otherwise %%{patches} macro will be empty "
-            "and both %%autosetup and `git am %%{patches}` will fail. "
+            "otherwise %{patches} macro will be empty "
+            "and both %autosetup and `git am %{patches}` will fail. "
             "Please move BuildArch AFTER SourceX and PatchX lines.")))
     if not sanity_check_patches_base(txt):
         hints.append(LintHint(spec_fn, 'E', (
@@ -139,19 +155,22 @@ def lint_report(hints, error_level=None):
     errors = hint_dict.get('E', [])
     n_errors = len(errors)
     if errors:
-        print("\n%d ERRORS found:" % n_errors)
+        print("\n{t.red}{n} ERRORS found:{t.normal}".format(
+            n=n_errors, t=log.term))
         for e in errors:
-            print(e)
+            print(e.pretty_str())
 
     warns = hint_dict.get('W', [])
     n_warns = len(warns)
     if warns:
-        print("\n%d WARNINGS found:" % n_warns)
+        print("\n{t.yellow}{n} WARNINGS found:{t.normal}".format(
+            n=n_warns, t=log.term))
         for e in warns:
-            print(e)
+            print(e.pretty_str())
 
     if n_errors == 0 and n_warns == 0:
-        print('no linting errors found \o/')
+        print("\n{t.green}no linting errors found \\o/{t.normal}".format(
+            t=log.term))
         return
 
     critical_error = False