Create config file if not exists

action.yml

@@ -49,6 +49,7 @@ runs:
       shell: bash
       run: >
         docker run --rm \
+          --env CREATE_DBT_BOUNCER_CONFIG_FILE=false \
           --env GITHUB_REF='${{ github.ref }}' \
           --env GITHUB_REPOSITORY='${{ github.repository }}' \
           --env GITHUB_RUN_ID='${{ github.run_id }}' \

src/dbt_bouncer/config_file_validator.py

@@ -1,8 +1,10 @@
 import logging
+import os
 import re
 from pathlib import Path, PurePath
-from typing import TYPE_CHECKING, Any, Dict, List, Literal, Mapping
+from typing import TYPE_CHECKING, Any, Dict, List, Literal, Mapping, Optional
 
+import click
 import toml
 from pydantic import ValidationError
 
@@ -13,6 +15,23 @@
         DbtBouncerConfAllCategories as DbtBouncerConf,
     )
 
+DEFAULT_DBT_BOUNCER_CONFIG = """manifest_checks:
+  - name: check_model_directories
+    include: ^models
+    permitted_sub_directories:
+      - intermediate
+      - marts
+      - staging
+  - name: check_model_names
+    include: ^models/staging
+    model_name_pattern: ^stg_
+catalog_checks:
+  - name: check_columns_are_documented_in_public_models
+run_results_checks:
+  - name: check_run_results_max_execution_time
+    max_execution_time_seconds: 60
+"""
+
 
 def conf_cls_factory(
     check_categories: List[
@@ -120,9 +139,16 @@ def get_config_file_path(
     return pyproject_toml_dir / "pyproject.toml"
 
 
-def load_config_file_contents(config_file_path: PurePath) -> Mapping[str, Any]:
+def load_config_file_contents(
+    config_file_path: PurePath,
+    allow_default_config_file_creation: Optional[bool] = None,
+) -> Mapping[str, Any]:
     """Load the contents of the config file.
 
+    Args:
+        config_file_path: Path to the config file.
+        allow_default_config_file_creation: Whether to allow the creation of a default config file if one does not exist. Used to allow pytesting of this function.
+
     Returns:
         Mapping[str, Any]: Config for dbt-bouncer.
 
@@ -137,9 +163,33 @@ def load_config_file_contents(config_file_path: PurePath) -> Mapping[str, Any]:
         if "dbt-bouncer" in toml_cfg["tool"]:
             return next(v for k, v in toml_cfg["tool"].items() if k == "dbt-bouncer")
         else:
-            raise RuntimeError(
-                "Please ensure your pyproject.toml file is correctly configured to work with `dbt-bouncer`. Alternatively, you can pass the path to your config file via the `--config-file` flag.",
+            logging.warning(
+                "Cannot find a `dbt-bouncer.yml` file or a `dbt-bouncer` section found in pyproject.toml."
             )
+            if (
+                allow_default_config_file_creation is True
+                and os.getenv("CREATE_DBT_BOUNCER_CONFIG_FILE") != "false"
+                and (
+                    os.getenv("CREATE_DBT_BOUNCER_CONFIG_FILE") == "true"
+                    or click.confirm(
+                        "Do you want `dbt-bouncer` to create a `dbt-bouncer.yml` file in the current directory?"
+                    )
+                )
+            ):
+                created_config_file = Path.cwd().joinpath("dbt-bouncer.yml")
+                created_config_file.touch()
+                logging.info(
+                    "A `dbt-bouncer.yml` file has been created in the current directory with default settings."
+                )
+                with Path.open(created_config_file, "w") as f:
+                    f.write(DEFAULT_DBT_BOUNCER_CONFIG)
+
+                return load_config_from_yaml(created_config_file)
+
+            else:
+                raise RuntimeError(
+                    "No configuration for `dbt-bouncer` could be found. You can pass the path to your config file via the `--config-file` flag. Alternatively, your pyproject.toml file can be configured to work with `dbt-bouncer`.",
+                )
     else:
         raise RuntimeError(
             f"Config file must be either a `pyproject.toml`, `.yaml` or `.yml` file. Got {config_file_path.suffix}."

src/dbt_bouncer/main.py

@@ -68,7 +68,9 @@ def cli(
         .get_parameter_source("config_file")
         .name,  # type: ignore[union-attr]
     )
-    config_file_contents = load_config_file_contents(config_file_path)
+    config_file_contents = load_config_file_contents(
+        config_file_path, allow_default_config_file_creation=True
+    )
 
     # Handle `severity` at the global level
     if config_file_contents.get("severity"):

tests/unit/test_config_file_validator.py

@@ -93,6 +93,30 @@ def test_get_file_config_path_pyproject_toml_recursive(monkeypatch, tmp_path):
     assert config_file_path == pyproject_file
 
 
+def test_load_config_file_contents_create_default_config_file(
+    monkeypatch,
+    tmp_path,
+):
+    monkeypatch.chdir(tmp_path)
+
+    pyproject_file = tmp_path / "pyproject.toml"
+    config = {"tool": {"dbt-bouncer-misspelled": PYPROJECT_TOML_SAMPLE_CONFIG}}
+    with Path.open(pyproject_file, "w") as f:
+        toml.dump(config, f)
+
+    with pytest.MonkeyPatch.context() as mp:
+        mp.setenv("CREATE_DBT_BOUNCER_CONFIG_FILE", "true")
+
+        contents = load_config_file_contents(
+            config_file_path=pyproject_file, allow_default_config_file_creation=True
+        )
+        assert list(contents.keys()) == [
+            "manifest_checks",
+            "catalog_checks",
+            "run_results_checks",
+        ]
+
+
 def test_load_config_file_contents_pyproject_toml_no_bouncer_section(
     monkeypatch,
     tmp_path,
@@ -105,7 +129,10 @@ def test_load_config_file_contents_pyproject_toml_no_bouncer_section(
         toml.dump(config, f)
 
     with pytest.raises(RuntimeError):
-        config = load_config_file_contents(config_file_path=tmp_path / "pyproject.toml")
+        config = load_config_file_contents(
+            config_file_path=tmp_path / "pyproject.toml",
+            allow_default_config_file_creation=False,
+        )
 
 
 invalid_confs = [