issue #106: import skeletal planner module.

ansible_mitogen/planner.py

@@ -0,0 +1,186 @@
+# Copyright 2017, David Wilson
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+# this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+# this list of conditions and the following disclaimer in the documentation
+# and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors
+# may be used to endorse or promote products derived from this software without
+# specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+
+"""
+This exists to detect every case defined in [0] and prepare arguments necessary
+for the executor implementation running within the target, including preloading
+any requisite files/Python modules known to be missing.
+
+[0] "Ansible Module Architecture", developing_program_flow_modules.html
+"""
+
+from __future__ import absolute_import
+from ansible.executor import module_common
+
+import mitogen
+import mitogen.service
+import ansible_mitogen.helpers
+
+
+class Planner(object):
+    """
+    A Planner receives a module name and the contents of its implementation
+    file, indicates whether or not it understands how to run the module, and
+    exports a method to run the module.
+    """
+    def detect(self, name, source):
+        assert 0
+
+    def run(self, connection, name, source, args, env):
+        assert 0
+
+
+class JsonArgsPlanner(Planner):
+    """
+    Script that has its interpreter directive and the task arguments
+    substituted into its source as a JSON string.
+    """
+    def detect(self, name, source):
+        return module_common.REPLACER_JSONARGS in source
+
+    def run(self, name, source, args, env):
+        path = None  # TODO
+        mitogen.service.call(501, ('register', path))
+        return {
+            'func': 'run_json_args_module',
+            'binary': source,
+            'args': args,
+            'env': env,
+        }
+
+
+class WantJsonPlanner(Planner):
+    """
+    If a module has the string WANT_JSON in it anywhere, Ansible treats it as a
+    non-native module that accepts a filename as its only command line
+    parameter. The filename is for a temporary file containing a JSON string
+    containing the module’s parameters. The module needs to open the file, read
+    and parse the parameters, operate on the data, and print its return data as
+    a JSON encoded dictionary to stdout before exiting.
+
+    These types of modules are self-contained entities. As of Ansible 2.1,
+    Ansible only modifies them to change a shebang line if present.
+    """
+    def detect(self, name, source):
+        return 'WANT_JSON' in source
+
+    def run(self, name, source, args, env):
+        return {
+            'func': 'run_want_json_module',
+            'binary': source,
+            'args': args,
+            'env': env,
+        }
+
+
+class ReplacerPlanner(Planner):
+    """
+    The Module Replacer framework is the original framework implementing
+    new-style modules. It is essentially a preprocessor (like the C
+    Preprocessor for those familiar with that programming language). It does
+    straight substitutions of specific substring patterns in the module file.
+    There are two types of substitutions.
+
+    * Replacements that only happen in the module file. These are public
+      replacement strings that modules can utilize to get helpful boilerplate
+      or access to arguments.
+
+      "from ansible.module_utils.MOD_LIB_NAME import *" is replaced with the
+      contents of the ansible/module_utils/MOD_LIB_NAME.py. These should only
+      be used with new-style Python modules.
+
+      "#<<INCLUDE_ANSIBLE_MODULE_COMMON>>" is equivalent to
+      "from ansible.module_utils.basic import *" and should also only apply to
+      new-style Python modules.
+
+      "# POWERSHELL_COMMON" substitutes the contents of
+      "ansible/module_utils/powershell.ps1". It should only be used with
+      new-style Powershell modules.
+    """
+    def detect(self, name, source):
+        return module_common.REPLACER in source
+
+    def run(self, name, source, args, env):
+        return {
+            'func': 'run_replacer_module',
+            'binary': source,
+            'args': args,
+            'env': env,
+        }
+
+
+class BinaryPlanner(Planner):
+    """
+    Binary modules take their arguments and will return data to Ansible in the
+    same way as want JSON modules.
+    """
+    helper = staticmethod(ansible_mitogen.helpers.run_binary)
+
+    def detect(self, name, source):
+        return module_common._is_binary(source)
+
+    def run(self, name, source, args, env):
+        return {
+            'func': 'run_binary_module',
+            'binary': source,
+            'args': args,
+            'env': env,
+        }
+
+
+class PythonPlanner(Planner):
+    """
+    The Ansiballz framework differs from module replacer in that it uses real
+    Python imports of things in ansible/module_utils instead of merely
+    preprocessing the module.
+    """
+    helper = staticmethod(ansible_mitogen.helpers.run_module)
+
+    def detect(self, name, source):
+        return True
+
+    def run(self, name, source, args, env):
+        return {
+            'func': 'run_python_module',
+            'module': name,
+            'args': args,
+            'env': env
+        }
+
+
+_planners = [
+    # JsonArgsPlanner,
+    # WantJsonPlanner,
+    # ReplacerPlanner,
+    BinaryPlanner,
+    PythonPlanner,
+]
+
+
+def plan():
+    pass