Update validate-modules (#20932)

* Update validate-modules

* Validates ANSIBLE_METADATA
* Ensures imports happen after documentation vars
* Some pep8 cleanup

* Clean up some left over unneeded code

* Update modules for new module guidelines and validate-modules checks

* Update imports for ec2_vpc_route_table and ec2_vpc_nat_gateway

test/sanity/validate-modules/utils.py

@@ -22,6 +22,9 @@ import sys
 # We only use StringIO, since we cannot setattr on cStringIO
 from StringIO import StringIO
 
+import yaml
+import yaml.reader
+
 
 def find_globals(g, tree):
     """Uses AST to find globals in an ast tree"""
@@ -66,3 +69,28 @@ class CaptureStd():
         """Return ``(stdout, stderr)``"""
 
         return self.stdout.getvalue(), self.stderr.getvalue()
+
+
+def parse_yaml(value, lineno, module, name):
+    traces = []
+    errors = []
+    data = None
+    try:
+        data = yaml.safe_load(value)
+    except yaml.MarkedYAMLError as e:
+        e.problem_mark.line += lineno - 1
+        e.problem_mark.name = '%s.%s' % (module, name)
+        errors.append('%s is not valid YAML. Line %d column %d' %
+                      (name, e.problem_mark.line + 1,
+                       e.problem_mark.column + 1))
+        traces.append(e)
+    except yaml.reader.ReaderError as e:
+        traces.append(e)
+        errors.append('%s is not valid YAML. Character '
+                      '0x%x at position %d.' %
+                      (name, e.character, e.position))
+    except yaml.YAMLError as e:
+        traces.append(e)
+        errors.append('%s is not valid YAML: %s: %s' % (name, type(e), e))
+
+    return data, errors, traces