Merge ~lgp171188/lpci:contain-config-file-path-under-project-dir into lpci:main

[Guruprasad]

Require the configuration file to be under the project directory

[Jürgen Gmach (jugmac00)]

There is one broken test and a couple of other things to have a look at.

review: Needs Fixing

[Jürgen Gmach (jugmac00)]

Thanks Guruprasad! Great discussion. I think everything should be clear now.

[Guruprasad (lgp171188)]

Replied to some review comments.

[Guruprasad (lgp171188)]

Jürgen, I have pushed 3 new commits to address all the open review comments. The resulting diff for this merge proposal is much simpler and cleaner.

[Jürgen Gmach (jugmac00)]

I think you need to rebase your MP.

[Guruprasad (lgp171188)]

Jürgen, I have rebased the MP and fixed the merge conflict now. Afaics, all the open review comments have been addressed. Please review again.

[Jürgen Gmach (jugmac00)]

Looks good!

review: Approve

[Jürgen Gmach (jugmac00)]

Please update RTD and create a new Snap once you have merged the MP.

diff --git a/NEWS.rst b/NEWS.rst
index 35216fe..daf4007 100644
--- a/NEWS.rst
+++ b/NEWS.rst
@@ -14,6 +14,8 @@ Version history
 
 - tox: The ``pip-compile`` env now upgrades the project's dependencies.
 
+- Require the configuration file to be present under the project directory.
+
 0.0.5   (2022-03-30)
 ====================
 
diff --git a/lpcraft/commands/tests/test_clean.py b/lpcraft/commands/tests/test_clean.py
index 5a11555..c445095 100644
--- a/lpcraft/commands/tests/test_clean.py
+++ b/lpcraft/commands/tests/test_clean.py
@@ -24,6 +24,35 @@ class TestClean(CommandBaseTestCase):
         os.chdir(self.tmp_project_path)
         self.addCleanup(os.chdir, cwd)
 
+    def test_config_file_not_under_project_directory(self):
+        paths = [
+            "/",
+            "/etc/init.d",
+            "../../foo",
+            "a/b/c/../../../../d",
+        ]
+
+        for path in paths:
+            config_file = f"{path}/config.yaml"
+            result = self.run_command(
+                "clean",
+                "-c",
+                config_file,
+            )
+            config_file_path = Path(config_file).resolve()
+            self.assertThat(
+                result,
+                MatchesStructure.byEquality(
+                    exit_code=1,
+                    errors=[
+                        ConfigurationError(
+                            f"'{config_file_path}' is not in the subpath of "
+                            f"'{self.tmp_project_path}'."
+                        )
+                    ],
+                ),
+            )
+
     def test_missing_config_file(self):
         result = self.run_command("clean")
 
diff --git a/lpcraft/commands/tests/test_run.py b/lpcraft/commands/tests/test_run.py
index cda2aaa..27baf8b 100644
--- a/lpcraft/commands/tests/test_run.py
+++ b/lpcraft/commands/tests/test_run.py
@@ -40,7 +40,7 @@ class LocalExecuteRun:
         *,
         cwd: Optional[Path] = None,
         env: Optional[Dict[str, Optional[str]]] = None,
-        **kwargs: Any
+        **kwargs: Any,
     ) -> "subprocess.CompletedProcess[AnyStr]":
         run_kwargs = kwargs.copy()
         run_kwargs["cwd"] = self.override_cwd
@@ -83,6 +83,35 @@ class RunBaseTestCase(CommandBaseTestCase):
 
 
 class TestRun(RunBaseTestCase):
+    def test_config_file_not_under_project_directory(self):
+        paths = [
+            "/",
+            "/etc/init.d",
+            "../../foo",
+            "a/b/c/../../../../d",
+        ]
+
+        for path in paths:
+            config_file = f"{path}/config.yaml"
+            result = self.run_command(
+                "run",
+                "-c",
+                config_file,
+            )
+            config_file_path = Path(config_file).resolve()
+            self.assertThat(
+                result,
+                MatchesStructure.byEquality(
+                    exit_code=1,
+                    errors=[
+                        ConfigurationError(
+                            f"'{config_file_path}' is not in the subpath of "
+                            f"'{self.tmp_project_path}'."
+                        )
+                    ],
+                ),
+            )
+
     def test_missing_config_file(self):
         result = self.run_command("run")
 
@@ -1630,6 +1659,37 @@ class TestRun(RunBaseTestCase):
 
 
 class TestRunOne(RunBaseTestCase):
+    def test_config_file_not_under_project_directory(self):
+        paths = [
+            "/",
+            "/etc/init.d",
+            "../../foo",
+            "a/b/c/../../../../d",
+        ]
+
+        for path in paths:
+            config_file = f"{path}/config.yaml"
+            result = self.run_command(
+                "run-one",
+                "-c",
+                config_file,
+                "test",
+                "0",
+            )
+            config_file_path = Path(config_file).resolve()
+            self.assertThat(
+                result,
+                MatchesStructure.byEquality(
+                    exit_code=1,
+                    errors=[
+                        ConfigurationError(
+                            f"'{config_file_path}' is not in the subpath of "
+                            f"'{self.tmp_project_path}'."
+                        )
+                    ],
+                ),
+            )
+
     def test_missing_config_file(self):
         result = self.run_command("run-one", "test", "0")
 
diff --git a/lpcraft/config.py b/lpcraft/config.py
index 0777dd3..07f17ff 100644
--- a/lpcraft/config.py
+++ b/lpcraft/config.py
@@ -10,6 +10,7 @@ from typing import Any, Dict, List, Optional, Union
 import pydantic
 from pydantic import StrictStr
 
+from lpcraft.errors import ConfigurationError
 from lpcraft.utils import load_yaml
 
 
@@ -127,5 +128,21 @@ class Config(ModelConfigDefaults):
     @classmethod
     def load(cls, path: Path) -> "Config":
         """Load config from the indicated file name."""
+        # XXX lgp171188 2022-03-31: it is not a good idea to evaluate
+        # `Path.cwd()` in multiple places to determine the project directory.
+        # This could be made available as an attribute on the `Config` class
+        # instead.
+        project_dir = Path.cwd()
+        resolved_path = path.resolve()
+        try:
+            # XXX lgp171188 2022-04-04: There is a new method,
+            # Path.is_relative_to() in Python 3.9+, which does
+            # exactly what we need. Once we drop support
+            # for Python 3.8, we should switch to that instead.
+            resolved_path.relative_to(project_dir)
+        except ValueError:
+            raise ConfigurationError(
+                f"'{resolved_path}' is not in the subpath of '{project_dir}'."
+            )
         content = load_yaml(path)
         return cls.parse_obj(content)
diff --git a/lpcraft/tests/test_config.py b/lpcraft/tests/test_config.py
index 96025b6..6867024 100644
--- a/lpcraft/tests/test_config.py
+++ b/lpcraft/tests/test_config.py
@@ -1,6 +1,7 @@
 # Copyright 2021-2022 Canonical Ltd.  This software is licensed under the
 # GNU General Public License version 3 (see the file LICENSE).
 
+import os
 from datetime import timedelta
 from pathlib import Path
 from textwrap import dedent
@@ -16,18 +17,37 @@ from testtools.matchers import (
 )
 
 from lpcraft.config import Config, OutputDistributeEnum
+from lpcraft.errors import CommandError
 
 
 class TestConfig(TestCase):
     def setUp(self):
         super().setUp()
         self.tempdir = Path(self.useFixture(TempDir()).path)
+        # `Path.cwd()` is assumed as the project directory.
+        # So switch to the created project directory.
+        os.chdir(self.tempdir)
 
     def create_config(self, text):
         path = self.tempdir / ".launchpad.yaml"
         path.write_text(text)
         return path
 
+    def test_load_config_not_under_project_dir(self):
+        paths_outside_project_dir = [
+            "/",
+            "/etc/init.d",
+            "../../foo",
+            "a/b/c/../../../../d",
+        ]
+        for path in paths_outside_project_dir:
+            config_file = Path(path) / "config.yaml"
+            self.assertRaises(
+                CommandError,
+                Config.load,
+                config_file,
+            )
+
     def test_load(self):
         path = self.create_config(
             dedent(