[Resolve Sceptre#288] Fix how user variables are accessed in config t…

…emplating (Sceptre#290)

Now variables supplied using the --var and --var-file command options
are available in the jinja templating as `{{ var.* }}`.

sceptre/cli/__init__.py

@@ -56,37 +56,38 @@ def cli(
     # Enable deprecation warnings
     warnings.simplefilter("always", DeprecationWarning)
     ctx.obj = {
-        "options": {},
+        "user_variables": {},
         "output_format": output,
         "no_colour": no_colour,
         "sceptre_dir": directory if directory else os.getcwd()
     }
-    user_variables = {}
     if var_file:
         for fh in var_file:
             parsed = yaml.safe_load(fh.read())
-            # intersection
-            overloaded_keys = set(user_variables.keys()) & set(parsed.keys())
+            ctx.obj["user_variables"].update(parsed)
+
+            # the rest of this block is for debug purposes only
+            existing_keys = set(ctx.obj["user_variables"].keys())
+            new_keys = set(parsed.keys())
+            overloaded_keys = existing_keys & new_keys  # intersection
             if overloaded_keys:
                 logger.debug(
                     "Duplicate variables encountered: {0}. "
                     "Using values from: {1}."
                     .format(", ".join(overloaded_keys), fh.name)
                 )
-            user_variables.update(parsed)
+
     if var:
         # --var options overwrite --var-file options
         for variable in var:
             variable_key, variable_value = variable.split("=")
-            if variable_key in user_variables:
+            if variable_key in ctx.obj["user_variables"]:
                 logger.debug(
                     "Duplicate variable encountered: {0}. "
                     "Using value from --var option."
                     .format(variable_key)
                 )
-            user_variables.update({variable_key: variable_value})
-    if user_variables:
-        ctx.obj["options"]["user_variables"] = user_variables
+            ctx.obj["user_variables"].update({variable_key: variable_value})
 
 
 cli.add_command(init_group)

sceptre/cli/helpers.py

@@ -91,7 +91,7 @@ def write(var, output_format="str", no_colour=True):
 
 def get_stack_or_env(ctx, path):
     """
-    Parses the path to generate relevant Envrionment and Stack object.
+    Parses the path to generate relevant Environment and Stack object.
 
     :param ctx: Cli context.
     :type ctx: click.Context
@@ -101,7 +101,9 @@ def get_stack_or_env(ctx, path):
     stack = None
     env = None
 
-    config_reader = ConfigReader(ctx.obj["sceptre_dir"], ctx.obj["options"])
+    config_reader = ConfigReader(
+        ctx.obj["sceptre_dir"], ctx.obj["user_variables"]
+    )
 
     if os.path.splitext(path)[1]:
         stack = config_reader.construct_stack(path)

tests/test_cli.py

@@ -17,6 +17,7 @@
 from sceptre.stack_status import StackStatus, StackChangeSetStatus
 from sceptre.cli.helpers import setup_logging, write, ColouredFormatter
 from sceptre.cli.helpers import CustomJsonEncoder, catch_exceptions
+from sceptre.cli.helpers import get_stack_or_env
 from botocore.exceptions import ClientError
 from sceptre.exceptions import SceptreException
 
@@ -103,7 +104,7 @@ def test_user_variables(self, command, files, output):
         @cli.command()
         @click.pass_context
         def noop(ctx):
-            click.echo(yaml.safe_dump(ctx.obj["options"]["user_variables"]))
+            click.echo(yaml.safe_dump(ctx.obj["user_variables"]))
 
         self.patcher_getcwd.stop()
         with self.runner.isolated_filesystem():
@@ -732,3 +733,39 @@ def test_CustomJsonEncoder_with_non_json_serialisable_object(self):
         encoder = CustomJsonEncoder()
         response = encoder.encode(datetime.datetime(2016, 5, 3))
         assert response == '"2016-05-03 00:00:00"'
+
+    def test_get_stack_or_env_with_stack(self):
+        ctx = MagicMock(obj={
+            "sceptre_dir": sentinel.sceptre_dir,
+            "user_variables": sentinel.user_variables
+        })
+        stack, env = get_stack_or_env(ctx, "stack.yaml")
+        self.mock_ConfigReader.assert_called_once_with(
+            sentinel.sceptre_dir, sentinel.user_variables
+        )
+        assert isinstance(stack, Stack)
+        assert env is None
+
+    def test_get_stack_or_env_with_nested_stack(self):
+        ctx = MagicMock(obj={
+            "sceptre_dir": sentinel.sceptre_dir,
+            "user_variables": sentinel.user_variables
+        })
+        stack, env = get_stack_or_env(ctx, "environment/dir/stack.yaml")
+        self.mock_ConfigReader.assert_called_once_with(
+            sentinel.sceptre_dir, sentinel.user_variables
+        )
+        assert isinstance(stack, Stack)
+        assert env is None
+
+    def test_get_stack_or_env_with_env(self):
+        ctx = MagicMock(obj={
+            "sceptre_dir": sentinel.sceptre_dir,
+            "user_variables": sentinel.user_variables
+        })
+        stack, env = get_stack_or_env(ctx, "environment/dir")
+        self.mock_ConfigReader.assert_called_once_with(
+            sentinel.sceptre_dir, sentinel.user_variables
+        )
+        assert isinstance(env, Environment)
+        assert stack is None