Adding a data parsing class for v2

v2/ansible/errors/__init__.py

@@ -21,11 +21,30 @@ __metaclass__ = type
 
 import os
 
+from ansible.parsing.yaml.strings import *
+
 class AnsibleError(Exception):
-    def __init__(self, message, obj=None):
-        # we import this here to prevent an import loop with errors
+    '''
+    This is the base class for all errors raised from Ansible code,
+    and can be instantiated with two optional parameters beyond the
+    error message to control whether detailed information is displayed
+    when the error occurred while parsing a data file of some kind.
+
+    Usage:
+
+        raise AnsibleError('some message here', obj=obj, show_content=True)
+
+    Where "obj" is some subclass of ansible.parsing.yaml.objects.AnsibleBaseYAMLObject,
+    which should be returned by the DataLoader() class.
+    '''
+
+    def __init__(self, message, obj=None, show_content=True):
+        # we import this here to prevent an import loop problem,
+        # since the objects code also imports ansible.errors
         from ansible.parsing.yaml.objects import AnsibleBaseYAMLObject
-        self._obj     = obj
+
+        self._obj = obj
+        self._show_content = show_content
         if isinstance(self._obj, AnsibleBaseYAMLObject):
             extended_error = self._get_extended_error()
             if extended_error:
@@ -36,22 +55,80 @@ class AnsibleError(Exception):
     def __repr__(self):
         return self.message
 
-    def _get_line_from_file(self, filename, line_number):
-        with open(filename, 'r') as f:
+    def _get_error_lines_from_file(self, file_name, line_number):
+        '''
+        Returns the line in the file which coresponds to the reported error
+        location, as well as the line preceeding it (if the error did not
+        occur on the first line), to provide context to the error.
+        '''
+
+        target_line = ''
+        prev_line = ''
+
+        with open(file_name, 'r') as f:
             lines = f.readlines()
-            return lines[line_number]
+
+            target_line = lines[line_number]
+            if line_number > 0:
+                prev_line = lines[line_number - 1]
+
+        return (target_line, prev_line)
 
     def _get_extended_error(self):
+        '''
+        Given an object reporting the location of the exception in a file, return
+        detailed information regarding it including:
+
+          * the line which caused the error as well as the one preceeding it
+          * causes and suggested remedies for common syntax errors
+
+        If this error was created with show_content=False, the reporting of content
+        is suppressed, as the file contents may be sensitive (ie. vault data).
+        '''
+
         error_message = ''
 
         try:
             (src_file, line_number, col_number) = self._obj.get_position_info()
-            error_message += 'The error occurred on line %d of the file %s:\n' % (line_number, src_file)
-            if src_file not in ('<string>', '<unicode>'):
-                responsible_line = self._get_line_from_file(src_file, line_number - 1)
-                if responsible_line:
-                    error_message += responsible_line
-                    error_message += (' ' * (col_number-1)) + '^'
+            error_message += YAML_POSITION_DETAILS % (src_file, line_number, col_number)
+            if src_file not in ('<string>', '<unicode>') and self._show_content:
+                (target_line, prev_line) = self._get_error_lines_from_file(src_file, line_number - 1)
+                if target_line:
+                    stripped_line = target_line.replace(" ","")
+                    arrow_line    = (" " * (col_number-1)) + "^"
+                    error_message += "%s\n%s\n%s\n" % (prev_line.rstrip(), target_line.rstrip(), arrow_line)
+
+                    # common error/remediation checking here:
+                    # check for unquoted vars starting lines
+                    if ('{{' in target_line and '}}' in target_line) and ('"{{' not in target_line or "'{{" not in target_line):
+                        error_message += YAML_COMMON_UNQUOTED_VARIABLE_ERROR
+                    # check for common dictionary mistakes
+                    elif ":{{" in stripped_line and "}}" in stripped_line:
+                        error_message += YAML_COMMON_DICT_ERROR
+                    # check for common unquoted colon mistakes
+                    elif len(target_line) and len(target_line) > 1 and len(target_line) > col_number and target_line[col_number] == ":" and target_line.count(':') > 1:
+                        error_message += YAML_COMMON_UNQUOTED_COLON_ERROR
+                    # otherwise, check for some common quoting mistakes
+                    else:
+                        parts = target_line.split(":")
+                        if len(parts) > 1:
+                            middle = parts[1].strip()
+                            match = False
+                            unbalanced = False
+
+                            if middle.startswith("'") and not middle.endswith("'"):
+                                match = True
+                            elif middle.startswith('"') and not middle.endswith('"'):
+                                match = True
+
+                            if len(middle) > 0 and middle[0] in [ '"', "'" ] and middle[-1] in [ '"', "'" ] and target_line.count("'") > 2 or target_line.count('"') > 2:
+                                unbalanced = True
+
+                            if match:
+                                error_message += YAML_COMMON_PARTIALLY_QUOTED_LINE_ERROR
+                            if unbalanced:
+                                error_message += YAML_COMMON_UNBALANCED_QUOTES_ERROR
+
         except IOError:
             error_message += '\n(could not open file to display line)'
         except IndexError: