Add local module support to the cloudformation package command

.gitignore

@@ -47,4 +47,5 @@ doc/source/tutorial/services.rst
 
 # Pyenv
 .python-version
+.env
 

awscli/customizations/cloudformation/artifact_exporter.py

@@ -25,11 +25,14 @@
 from awscli.customizations.cloudformation import exceptions
 from awscli.customizations.cloudformation.yamlhelper import yaml_dump, \
     yaml_parse
+from awscli.customizations.cloudformation import modules
 import jmespath
 
 
 LOG = logging.getLogger(__name__)
 
+MODULES = "Modules"
+RESOURCES = "Resources"
 
 def is_path_value_valid(path):
     return isinstance(path, str)
@@ -591,8 +594,8 @@ def __init__(self, template_path, parent_dir, uploader,
             raise ValueError("parent_dir parameter must be "
                              "an absolute path to a folder {0}"
                              .format(parent_dir))
-
         abs_template_path = make_abs_path(parent_dir, template_path)
+        self.module_parent_path = abs_template_path
         template_dir = os.path.dirname(abs_template_path)
 
         with open(abs_template_path, "r") as handle:
@@ -651,14 +654,39 @@ def export(self):
         :return: The template with references to artifacts that have been
         exported to s3.
         """
+
+        # Process modules
+        try:
+            self.template_dict = modules.process_module_section(
+                    self.template_dict, 
+                    self.template_dir,
+                    self.module_parent_path)
+        except Exception as e:
+            msg=f"Failed to process Modules section: {e}"
+            LOG.exception(msg)
+            raise exceptions.InvalidModuleError(msg=msg)
+
         self.template_dict = self.export_metadata(self.template_dict)
 
-        if "Resources" not in self.template_dict:
+        if RESOURCES not in self.template_dict:
             return self.template_dict
 
+        # Process modules that are specified as Resources, not in Modules
+        try:
+            self.template_dict = modules.process_resources_section(
+                    self.template_dict, 
+                    self.template_dir, 
+                    self.module_parent_path, 
+                    None)
+        except Exception as e:
+            msg=f"Failed to process modules in Resources: {e}"
+            LOG.exception(msg)
+            raise exceptions.InvalidModuleError(msg=msg)
+
+
         self.template_dict = self.export_global_artifacts(self.template_dict)
 
-        self.export_resources(self.template_dict["Resources"])
+        self.export_resources(self.template_dict[RESOURCES])
 
         return self.template_dict
 

awscli/customizations/cloudformation/exceptions.py

@@ -57,3 +57,9 @@ class DeployBucketRequiredError(CloudFormationCommandError):
 
 class InvalidForEachIntrinsicFunctionError(CloudFormationCommandError):
     fmt = 'The value of {resource_id} has an invalid "Fn::ForEach::" format: Must be a list of three entries'
+
+class InvalidModulePathError(CloudFormationCommandError):
+    fmt = 'The value of {source} is not a valid path to a local file'
+
+class InvalidModuleError(CloudFormationCommandError):
+    fmt = 'Invalid module: {msg}'

awscli/customizations/cloudformation/module_conditions.py

@@ -0,0 +1,116 @@
+# Copyright 2012-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"). You
+# may not use this file except in compliance with the License. A copy of
+# the License is located at
+#
+# http://aws.amazon.com/apache2.0/
+#
+# or in the "license" file accompanying this file. This file is
+# distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF
+# ANY KIND, either express or implied. See the License for the specific
+# language governing permissions and limitations under the License.
+
+# pylint: disable=fixme
+
+"""
+Parse the Conditions section in a module
+
+This section is not emitted into the output.
+We have to be able to fully resolve it locally.
+"""
+
+from awscli.customizations.cloudformation import exceptions
+
+AND = "Fn::And"
+EQUALS = "Fn::Equals"
+IF = "Fn::If"
+NOT = "Fn::Not"
+OR = "Fn::Or"
+REF = "Ref"
+CONDITION = "Condition"
+
+
+def parse_conditions(d, find_ref):
+    """Parse conditions and return a map of name:boolean"""
+    retval = {}
+
+    for k, v in d.items():
+        retval[k] = istrue(v, find_ref, retval)
+
+    return retval
+
+
+def resolve_if(v, find_ref, prior):
+    "Resolve Fn::If"
+    msg = f"If expression should be a list with 3 elements: {v}"
+    if not isinstance(v, list):
+        raise exceptions.InvalidModuleError(msg=msg)
+    if len(v) != 3:
+        raise exceptions.InvalidModuleError(msg=msg)
+    if istrue(v[0], find_ref, prior):
+        return v[1]
+    return v[2]
+
+
+# pylint: disable=too-many-branches,too-many-statements
+def istrue(v, find_ref, prior):
+    "Recursive function to evaluate a Condition"
+    retval = False
+    if EQUALS in v:
+        eq = v[EQUALS]
+        if len(eq) == 2:
+            val0 = eq[0]
+            val1 = eq[1]
+            if IF in val0:
+                val0 = resolve_if(val0[IF], find_ref, prior)
+            if IF in val1:
+                val1 = resolve_if(val1[IF], find_ref, prior)
+            if REF in val0:
+                val0 = find_ref(val0[REF])
+            if REF in val1:
+                val1 = find_ref(val1[REF])
+            retval = val0 == val1
+        else:
+            msg = f"Equals expression should be a list with 2 elements: {eq}"
+            raise exceptions.InvalidModuleError(msg=msg)
+    if NOT in v:
+        if not isinstance(v[NOT], list):
+            msg = f"Not expression should be a list with 1 element: {v[NOT]}"
+            raise exceptions.InvalidModuleError(msg=msg)
+        retval = not istrue(v[NOT][0], find_ref, prior)
+    if AND in v:
+        vand = v[AND]
+        msg = f"And expression should be a list with 2 elements: {vand}"
+        if not isinstance(vand, list):
+            raise exceptions.InvalidModuleError(msg=msg)
+        if len(vand) != 2:
+            raise exceptions.InvalidModuleError(msg=msg)
+        retval = istrue(vand[0], find_ref, prior) and istrue(
+            vand[1], find_ref, prior
+        )
+    if OR in v:
+        vor = v[OR]
+        msg = f"Or expression should be a list with 2 elements: {vor}"
+        if not isinstance(vor, list):
+            raise exceptions.InvalidModuleError(msg=msg)
+        if len(vor) != 2:
+            raise exceptions.InvalidModuleError(msg=msg)
+        retval = istrue(vor[0], find_ref, prior) or istrue(
+            vor[1], find_ref, prior
+        )
+    if IF in v:
+        # Shouldn't ever see an IF here
+        msg = f"Unexpected If: {v[IF]}"
+        raise exceptions.InvalidModuleError(msg=msg)
+    if CONDITION in v:
+        condition_name = v[CONDITION]
+        if condition_name in prior:
+            retval = prior[condition_name]
+        else:
+            msg = f"Condition {condition_name} was not evaluated yet"
+            raise exceptions.InvalidModuleError(msg=msg)
+            # TODO: Should we re-order the conditions?
+            # We are depending on the author putting them in order
+
+    return retval