[Resolve #1135] Fix path to templates (#1141)

Currently the root file path for the template file handler points to a different
location than the existing template_path. This makes the migration process
confusing and arduous for users. Therefore when a user specifies a relative
path to the file we make both parameters point to the same location, the
`sceptre_project_dir/templates` directory.

docs/_source/docs/template_handlers.rst

@@ -5,9 +5,6 @@ Template handlers can be used to resolve a ``template`` config block to a CloudF
 fetch templates from S3, for example. Users can create their own template handlers to easily add support for other
 template loading mechanisms. See `Custom Template Handlers`_ for more information.
 
-When a ``template_path`` property is specified in the Stack config, it is wired into a ``file`` template handler by
-default. This saves you from having to specify a full ``template`` block if you just want to load a file from disk.
-
 .. warning::
 
    The ``template_path`` key is deprecated in favor of the ``template`` key.
@@ -18,10 +15,11 @@ Available Template Handlers
 file
 ~~~~~~~~~~~~~~~~~~~~
 
-Loads a template from disk. Supports JSON, YAML, Jinja2 and Python files. Will be used if the ``template_path`` Stack
-config property is set, for backwards compatibility reasons.
+Loads a template from the local file system. This handler supports templates with .json, .yaml, .template, .j2
+and .py extensions.  This is the default template handler type, specifying the ``file`` type is optional.
 
-This is the default template handler type, setting the ``file`` type is optional.
+For backwards compatability, when a ``template_path`` key is specified in the Stack config, it is wired to
+use the ``file`` template handler.
 
 Syntax:
 
@@ -40,8 +38,8 @@ Example:
 
 .. note::
 
-   The path for the ``template_path`` property is relative to the sceptre_dir/templates directory while the path for
-   this template ``path`` property is relative to the current working directory.
+   The ``path`` property can contain an absolute or relative path to the template file.
+   This handler assumes a relative path to be from sceptre_project_dir/templates
 
 
 s3

sceptre/config/reader.py

@@ -568,7 +568,6 @@ def _parsed_stack_group_config(self, stack_group_config):
             for key in
             set(stack_group_config) - set(CONFIG_MERGE_STRATEGIES)
         }
-        parsed_config.pop("project_path")
         parsed_config.pop("stack_group_path")
         return parsed_config
 

sceptre/template_handlers/file.py

@@ -1,7 +1,7 @@
-import logging
 import os
 import sceptre.template_handlers.helper as helper
 
+from pathlib import Path
 from sceptre.exceptions import UnsupportedTemplateFileTypeError
 from sceptre.template_handlers import TemplateHandler
 
@@ -12,7 +12,6 @@ class File(TemplateHandler):
     """
 
     def __init__(self, *args, **kwargs):
-        self.logger = logging.getLogger(__name__)
         super(File, self).__init__(*args, **kwargs)
 
     def schema(self):
@@ -25,28 +24,33 @@ def schema(self):
         }
 
     def handle(self):
-        file_extension = os.path.splitext(self.arguments["path"])[1]
-        path = self.arguments["path"]
+        project_path = self.stack_group_config.get("project_path")
+        input_path = Path(self.arguments["path"])
+        if input_path.is_absolute():
+            path = str(input_path)
+        else:
+            path = str(Path(project_path) / 'templates' / input_path)
+
+        if input_path.suffix not in self.supported_template_extensions:
+            raise UnsupportedTemplateFileTypeError(
+                "Template has file extension %s. Only %s are supported.",
+                input_path.suffix, ",".join(self.supported_template_extensions)
+            )
+
         try:
-            if file_extension in {".json", ".yaml", ".template"}:
+            if input_path.suffix in self.standard_template_extensions:
                 with open(path) as template_file:
                     return template_file.read()
-            elif file_extension == ".j2":
+            elif input_path.suffix in self.jinja_template_extensions:
                 return helper.render_jinja_template(
                     os.path.dirname(path),
                     os.path.basename(path),
                     {"sceptre_user_data": self.sceptre_user_data},
                     self.stack_group_config.get("j2_environment", {})
                 )
-            elif file_extension == ".py":
+            elif input_path.suffix in self.python_template_extensions:
                 return helper.call_sceptre_handler(path,
                                                    self.sceptre_user_data)
-            else:
-                raise UnsupportedTemplateFileTypeError(
-                    "Template has file extension %s. Only .py, .yaml, "
-                    ".template, .json and .j2 are supported.",
-                    os.path.splitext(path)[1]
-                )
         except Exception as e:
             helper.print_template_traceback(path)
             raise e

tests/test_config_reader.py

@@ -326,6 +326,7 @@ def test_construct_stacks_constructs_stack(
             template_bucket_name='stack_group_template_bucket_name',
             template_key_prefix=None,
             stack_group_config={
+                "project_path": self.context.project_path,
                 "custom_key": "custom_value"
             }
         )

tests/test_template.py

@@ -44,7 +44,9 @@ def setup_method(self, test_method):
             name="template_name",
             handler_config={"type": "file", "path": "/folder/template.py"},
             sceptre_user_data={},
-            stack_group_config={},
+            stack_group_config={
+                "project_path": "projects"
+            },
             connection_manager=connection_manager,
         )