Fix CodeBuild provider spec_inline support

**What was the problem?**

1. The `spec_inline` property was documented and type checked as a string.
   Whereas the CDK function used to include the `spec_inline` expects an
   object instead.

2. If CodeBuild was used as a deployment provider, it would not be able
   to use the `spec_inline`. Nor would you be able to specify
   `spec_inline` as part of a target definition. Even though the schema
   validation made it look like it would support `spec_inline`.

**What has been changed?**

* Updates the schema validation to support objects, as required
  by the CDK BuildSpec construct.
* Changes the CodeBuild provider for deployment and build stages, such that
  both support inline and file reference usage of BuildSpec definitions.
* When both the `spec_inline` and `spec_filename` properties are defined as
  part of the default provider or target properties, an error message will be
  thrown.
* Tests have been added to verify that the added method works as
  intended.

Author: sbkok

docs/providers-guide.md

@@ -197,12 +197,25 @@ Provider type: `codebuild`.
   > If you wish to pass in a custom inline Buildspec as a string for the
   > CodeBuild Project this would override any `buildspec.yml` file.
   > Read more [here](https://docs.aws.amazon.com/codebuild/latest/userguide/build-spec-ref.html#build-spec-ref-example).
+  >
+  > Note: Either specify the `spec_inline` or the `spec_filename` in the
+  > properties block. If both are supplied, the pipeline generator will throw
+  > an error instead.
 - *spec_filename* *(String)* default: `buildspec.yml`.
   > If you wish to pass in a custom Buildspec file that is within the
   > repository. This is useful for custom deploy type actions where CodeBuild
   > will perform the execution of the commands. Path is relational to the
   > root of the repository, so `build/buidlspec.yml` refers to the
   > `buildspec.yml` stored in the `build` directory of the repository.
+  >
+  > In case CodeBuild is used as a deployment provider, the default BuildSpec
+  > file name is `deployspec.yml` instead. In case you would like to test
+  > a given environment using CodeBuild, you can rename it to `testspec.yml`
+  > or something similar using this property.
+  >
+  > Note: Either specify the `spec_inline` or the `spec_filename` in the
+  > properties block. If both are supplied, the pipeline generator will throw
+  > an error instead.
 
 ### Jenkins
 

src/lambda_codebase/initial_commit/bootstrap_repository/adf-build/shared/cdk/cdk_constructs/adf_codebuild.py

@@ -19,6 +19,8 @@
 ADF_DEPLOYMENT_REGION = os.environ["AWS_REGION"]
 ADF_DEPLOYMENT_ACCOUNT_ID = os.environ["ACCOUNT_ID"]
 DEFAULT_CODEBUILD_IMAGE = "UBUNTU_14_04_PYTHON_3_7_1"
+DEFAULT_BUILD_SPEC_FILENAME = 'buildspec.yml'
+DEFAULT_DEPLOY_SPEC_FILENAME = 'deployspec.yml'
 
 class CodeBuild(core.Construct):
     # pylint: disable=no-value-for-parameter
@@ -45,10 +47,10 @@ def __init__(self, scope: core.Construct, id: str, shared_modules_bucket: str, d
                 environment_variables=CodeBuild.generate_build_env_variables(_codebuild, shared_modules_bucket, map_params, target),
                 privileged=target.get('properties', {}).get('privileged', False) or map_params['default_providers']['build'].get('properties', {}).get('privileged', False)
             )
-            _spec_filename = (
-                target.get('properties', {}).get('spec_filename') or
-                map_params['default_providers']['deploy'].get('properties', {}).get('spec_filename') or
-                'deployspec.yml'
+            build_spec = CodeBuild.determine_build_spec(
+                id,
+                map_params['default_providers']['deploy'].get('properties', {}),
+                target,
             )
             _codebuild.PipelineProject(
                 self,
@@ -59,7 +61,7 @@ def __init__(self, scope: core.Construct, id: str, shared_modules_bucket: str, d
                 project_name="adf-deploy-{0}".format(id),
                 timeout=core.Duration.minutes(_timeout),
                 role=_iam.Role.from_role_arn(self, 'build_role', role_arn=_build_role, mutable=False),
-                build_spec=_codebuild.BuildSpec.from_source_filename(_spec_filename)
+                build_spec=build_spec,
             )
             self.deploy = Action(
                 name="{0}".format(id),
@@ -85,18 +87,10 @@ def __init__(self, scope: core.Construct, id: str, shared_modules_bucket: str, d
             )
             if map_params['default_providers']['build'].get('properties', {}).get('role'):
                 ADF_DEFAULT_BUILD_ROLE = 'arn:aws:iam::{0}:role/{1}'.format(ADF_DEPLOYMENT_ACCOUNT_ID, map_params['default_providers']['build'].get('properties', {}).get('role'))
-            _build_stage_spec = map_params['default_providers']['build'].get('properties', {}).get('spec_filename')
-            _build_inline_spec = map_params['default_providers']['build'].get(
-                'properties', {}).get(
-                    'spec_inline', '') or map_params['default_providers']['build'].get(
-                        'properties', {}).get(
-                            'spec_inline', '')
-            if _build_stage_spec:
-                _spec = _codebuild.BuildSpec.from_source_filename(_build_stage_spec)
-            elif _build_inline_spec:
-                _spec = _codebuild.BuildSpec.from_object(_build_inline_spec)
-            else:
-                _spec = None
+            build_spec = CodeBuild.determine_build_spec(
+                id,
+                map_params['default_providers']['build'].get('properties', {})
+            )
             _codebuild.PipelineProject(
                 self,
                 'project',
@@ -105,7 +99,7 @@ def __init__(self, scope: core.Construct, id: str, shared_modules_bucket: str, d
                 description="ADF CodeBuild Project for {0}".format(map_params['name']),
                 project_name="adf-build-{0}".format(map_params['name']),
                 timeout=core.Duration.minutes(_timeout),
-                build_spec=_spec,
+                build_spec=build_spec,
                 role=_iam.Role.from_role_arn(self, 'default_build_role', role_arn=_build_role, mutable=False)
             )
             self.build = _codepipeline.CfnPipeline.StageDeclarationProperty(
@@ -122,6 +116,49 @@ def __init__(self, scope: core.Construct, id: str, shared_modules_bucket: str, d
                 ]
             )
 
+    @staticmethod
+    def _determine_stage_build_spec(codebuild_id, props, stage_name, default_filename):
+        filename = props.get('spec_filename')
+        spec_inline = props.get('spec_inline', {})
+        if filename and spec_inline:
+            raise Exception(
+                "The spec_filename and spec_inline are both present "
+                "inside the {0} stage definition of {1}. "
+                "Whereas only one of these two is allowed.".format(
+                    stage_name,
+                    codebuild_id,
+                ),
+            )
+
+        if spec_inline:
+            return _codebuild.BuildSpec.from_object(spec_inline)
+
+        return _codebuild.BuildSpec.from_source_filename(
+            filename or default_filename,
+        )
+
+    @staticmethod
+    def determine_build_spec(codebuild_id, default_props, target=None):
+        if target:
+            target_props = target.get('properties', {})
+            if 'spec_inline' in target_props or 'spec_filename' in target_props:
+                return CodeBuild._determine_stage_build_spec(
+                    codebuild_id=codebuild_id,
+                    props=target_props,
+                    stage_name='deploy target',
+                    default_filename=DEFAULT_DEPLOY_SPEC_FILENAME,
+                )
+        return CodeBuild._determine_stage_build_spec(
+            codebuild_id=codebuild_id,
+            props=default_props,
+            stage_name='default {}'.format('deploy' if target else 'build'),
+            default_filename=(
+                DEFAULT_DEPLOY_SPEC_FILENAME
+                if target
+                else DEFAULT_BUILD_SPEC_FILENAME
+            ),
+        )
+
     @staticmethod
     def determine_build_image(scope, target, map_params):
         specific_image = None