ini_file should only change what was specified and nothing more #5860

See also:
http://alesnosek.com/blog/2015/08/03/improving-ansibles-ini-file-module/

files/ini_file.py

@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 
 # (c) 2012, Jan-Piet Mens <jpmens () gmail.com>
+# (c) 2015, Ales Nosek <anosek.nosek () gmail.com>
 #
 # This file is part of Ansible
 #
@@ -79,7 +80,7 @@ notes:
      Either use M(template) to create a base INI file with a C([default]) section, or use
      M(lineinfile) to add the missing line.
 requirements: [ ConfigParser ]
-author: "Jan-Piet Mens (@jpmens)"
+author: "Jan-Piet Mens (@jpmens), Ales Nosek"
 '''
 
 EXAMPLES = '''
@@ -101,79 +102,77 @@ import sys
 
 def do_ini(module, filename, section=None, option=None, value=None, state='present', backup=False):
 
-    changed = False
-    if (sys.version_info[0] == 2 and sys.version_info[1] >= 7) or sys.version_info[0] >= 3: 
-        cp = ConfigParser.ConfigParser(allow_no_value=True)
-    else:
-        cp = ConfigParser.ConfigParser()
-    cp.optionxform = identity
-
-    try:
-        f = open(filename)
-        cp.readfp(f)
-    except IOError:
-        pass
-
-
-    if state == 'absent':
-        if option is None:
-            changed = cp.remove_section(section)
-        else:
-            try:
-                changed = cp.remove_option(section, option)
-            except ConfigParser.NoSectionError:
-                # Option isn't present if the section isn't either
-                pass
-
-    if state == 'present':
 
-        # DEFAULT section is always there by DEFAULT, so never try to add it.
-        if not cp.has_section(section) and section.upper() != 'DEFAULT':
+    with open(filename, 'r') as ini_file:
+        ini_lines = ini_file.readlines()
+        # append a fake section line to simplify the logic
+        ini_lines.append('[')
 
-            cp.add_section(section)
-            changed = True
+    within_section = not section
+    section_start = 0
+    changed = False
 
-        if option is not None and value is not None:
-            try:
-                oldvalue = cp.get(section, option)
-                if str(value) != str(oldvalue):
-                    cp.set(section, option, value)
+    for index, line in enumerate(ini_lines):
+        if line.startswith('[%s]' % section):
+            within_section = True
+            section_start = index
+        elif line.startswith('['):
+            if within_section:
+                if state == 'present':
+                    # insert missing option line at the end of the section
+                    ini_lines.insert(index, '%s = %s\n' % (option, value))
+                    changed = True
+                elif state == 'absent' and not option:
+                    # remove the entire section
+                    del ini_lines[section_start:index]
                     changed = True
-            except ConfigParser.NoSectionError:
-                cp.set(section, option, value)
-                changed = True
-            except ConfigParser.NoOptionError:
-                cp.set(section, option, value)
-                changed = True
-            except ConfigParser.InterpolationError:
-                cp.set(section, option, value)
-                changed = True
+                break
+        else:
+            if within_section and option:
+                if state == 'present':
+                    # change the existing option line
+                    if re.match('%s *=' % option, line) \
+                            or re.match('# *%s *=' % option, line) \
+                            or re.match('; *%s *=' % option, line):
+                        newline = '%s = %s\n' % (option, value)
+                        changed = ini_lines[index] != newline
+                        ini_lines[index] = newline
+                        if changed:
+                            # remove all possible option occurences from the rest of the section
+                            index = index + 1
+                            while index < len(ini_lines):
+                                line = ini_lines[index]
+                                if line.startswith('['):
+                                    break
+                                if re.match('%s *=' % option, line):
+                                    del ini_lines[index]
+                                else:
+                                    index = index + 1
+                        break
+                else:
+                    # comment out the existing option line
+                    if re.match('%s *=' % option, line):
+                        ini_lines[index] = '#%s' % ini_lines[index]
+                        changed = True
+                        break
+
+    # remove the fake section line
+    del ini_lines[-1:]
+
+    if not within_section and option and state == 'present':
+        ini_lines.append('[%s]\n' % section)
+        ini_lines.append('%s = %s\n' % (option, value))
+        changed = True
+
 
     if changed and not module.check_mode:
         if backup:
             module.backup_local(filename)
-
-        try:
-            f = open(filename, 'w')
-            cp.write(f)
-        except:
-            module.fail_json(msg="Can't create %s" % filename)
+        with open(filename, 'w') as ini_file:
+            ini_file.writelines(ini_lines)
 
     return changed
 
-# ==============================================================
-# identity
-
-def identity(arg):
-    """
-    This function simply returns its argument. It serves as a
-    replacement for ConfigParser.optionxform, which by default
-    changes arguments to lower case. The identity function is a
-    better choice than str() or unicode(), because it is
-    encoding-agnostic.
-    """
-    return arg
-
 # ==============================================================
 # main