refactor: strengthen configuration validation at startup

Motivation:
Validating configuration at runtime is brittle and can lead to silent
fail-open failures. Moving validation to the configuration layer ensures
that the application starts with a known-good state.

Design Choices:
- Added a field_validator to Settings for obs_download_url to ensure it
  contains a valid hostname.
- Introduced a repo_mirror_host property in Settings for centralized and
  safe hostname extraction.
- Refactored RepoConfig and get_repo_url to use the pre-validated
  repo_mirror_host.
- Removed redundant runtime checks and suppressed exceptions in
  verify_repo_exists.
- Added comprehensive tests for the new validator and property in
  tests/test_config.py.

User Benefits:
- Faster failure on malformed configuration.
- More robust and predictable repository verification logic.

Author: okurz

openqabot/config.py

@@ -10,9 +10,10 @@
 
 from pathlib import Path
 from typing import Any
+from urllib.parse import urlparse
 
 import osc.conf
-from pydantic import Field
+from pydantic import Field, field_validator
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 
@@ -73,6 +74,15 @@ class Settings(BaseSettings):
     # How long to wait for http(s) call in seconds
     url_timeout: int = 60
 
+    @field_validator("obs_download_url")
+    @classmethod
+    def validate_obs_download_url(cls, v: str) -> str:
+        """Validate that obs_download_url has a valid hostname."""
+        if not urlparse(v).netloc:
+            msg = f"OBS_DOWNLOAD_URL '{v}' does not contain a valid hostname"
+            raise ValueError(msg)
+        return v
+
     model_config = SettingsConfigDict(
         env_file=".env",
         env_file_encoding="utf-8",
@@ -110,6 +120,11 @@ def git_review_bot_user(self) -> str | None:
             return self.git_review_bot
         return self.obs_group + "-review"
 
+    @property
+    def repo_mirror_host(self) -> str:
+        """Extract the repository mirror host from obs_download_url."""
+        return urlparse(self.obs_download_url).netloc
+
     @property
     def obs_products_set(self) -> set[str]:
         """Return the set of OBS products to consider."""

openqabot/loader/gitea.py

@@ -330,8 +330,6 @@ def verify_repo_exists(
     if not product_version:
         return True
     repo_url = get_repo_url(target, product_version, config)
-    if not repo_url:
-        return True
     with suppress(requests.exceptions.RequestException):
         response = retried_requests.head(repo_url, allow_redirects=True)
         if response.status_code == HTTPStatus.NOT_FOUND:
@@ -436,6 +434,7 @@ def add_build_result(
         repo_type=config.settings.obs_repo_type or "product",
         download_base_url=config.settings.download_base_url,
         obs_download_url=config.settings.obs_download_url,
+        repo_mirror_host=config.settings.repo_mirror_host,
         obs_products=config.settings.obs_products_set,
     )
     target = Repos(product=project, version=product, arch=res.get("arch"))

openqabot/types/gitea.py

@@ -14,4 +14,5 @@ class RepoConfig:
     repo_type: str
     download_base_url: str
     obs_download_url: str
+    repo_mirror_host: str
     obs_products: set[str] | None = None

openqabot/utils.py

@@ -9,7 +9,6 @@
 import re
 from copy import deepcopy
 from typing import TYPE_CHECKING, Any
-from urllib.parse import urlparse
 
 from requests import Session
 from requests.adapters import HTTPAdapter
@@ -116,10 +115,7 @@ def get_repo_url(
     config: RepoConfig,
 ) -> str:
     """Construct the repository URL for a given project and architecture."""
-    host = urlparse(config.obs_download_url).netloc
-    if not host:
-        return ""
-    base = config.download_base_url.replace("%REPO_MIRROR_HOST%", host)
+    base = config.download_base_url.replace("%REPO_MIRROR_HOST%", config.repo_mirror_host)
     project_path = target.product.replace(":", ":/")
     return (
         f"{base}/{project_path}/{config.repo_type}/repo/{target.version}-{product_version}-{target.arch}/{target.arch}/"

tests/test_config.py

@@ -6,6 +6,9 @@
 from pathlib import Path
 from unittest.mock import patch
 
+import pytest
+from pydantic import ValidationError
+
 from openqabot.config import Settings, get_default_obs_url
 
 
@@ -89,3 +92,23 @@ def test_insecure_setting() -> None:
 
     settings = Settings(insecure=False)
     assert settings.insecure is False
+
+
+def test_obs_download_url_validation() -> None:
+    """Test validation of obs_download_url."""
+    # Valid URL
+    settings = Settings(obs_download_url="http://download.suse.de/ibs")
+    assert settings.obs_download_url == "http://download.suse.de/ibs"
+
+    # Invalid URL (no hostname)
+    with pytest.raises(ValidationError, match="OBS_DOWNLOAD_URL 'invalid-url' does not contain a valid hostname"):
+        Settings(obs_download_url="invalid-url")
+
+
+def test_repo_mirror_host_property() -> None:
+    """Test the repo_mirror_host property."""
+    settings = Settings(obs_download_url="http://download.suse.de/ibs")
+    assert settings.repo_mirror_host == "download.suse.de"
+
+    settings = Settings(obs_download_url="https://mirror.example.com/path")
+    assert settings.repo_mirror_host == "mirror.example.com"

tests/test_loader_gitea_build_results.py

@@ -308,6 +308,7 @@ def test_verify_repo_exists_status_codes(
             repo_type="product",
             download_base_url="http://example.com",
             obs_download_url="http://download.suse.de/ibs",
+            repo_mirror_host="download.suse.de",
         ),
     )
 
@@ -325,6 +326,7 @@ def test_verify_repo_exists_no_product_version(mocker: MockerFixture) -> None:
             repo_type="product",
             download_base_url="http://example.com",
             obs_download_url="http://download.suse.de/ibs",
+            repo_mirror_host="download.suse.de",
         ),
     )
 
@@ -349,6 +351,7 @@ def test_verify_repo_exists_missing_urls(download_base: str, obs_download: str)
             repo_type="product",
             download_base_url=download_base,
             obs_download_url=obs_download,
+            repo_mirror_host="example.com",
         ),
     )
 
@@ -364,6 +367,7 @@ def test_verify_repo_exists_invalid_obs_url() -> None:
             repo_type="product",
             download_base_url="http://example.com",
             obs_download_url="invalid-url-no-slashes",
+            repo_mirror_host="",
         ),
     )
 

tests/test_loader_gitea_helpers.py

@@ -162,6 +162,7 @@ def test_add_channel_for_build_result_local() -> None:
             repo_type="product",
             download_base_url="http://base.url",
             obs_download_url="http://obs.url",
+            repo_mirror_host="obs.url",
             obs_products={"all"},
         ),
     )