Introduce FastAPI healthz and system endpoints

Author: lbarcziova

packit_service/service/api_v1/__init__.py

@@ -1,4 +1,7 @@
 # Copyright Contributors to the Packit project.
 # SPDX-License-Identifier: MIT
 
-routers = []
+from .healthz import router as healthz_router
+from .system import router as system_router
+
+routers = [healthz_router, system_router]

packit_service/service/api_v1/healthz.py

@@ -0,0 +1,12 @@
+# Copyright Contributors to the Packit project.
+# SPDX-License-Identifier: MIT
+
+from fastapi import APIRouter
+
+router = APIRouter()
+
+
+@router.get("/healthz")
+async def health_check() -> dict:
+    """Health check"""
+    return {"status": "ok"}

packit_service/service/api_v1/system.py

@@ -0,0 +1,60 @@
+# Copyright Contributors to the Packit project.
+# SPDX-License-Identifier: MIT
+
+import re
+from logging import getLogger
+from typing import Optional
+
+import ogr
+import packit
+import specfile
+from fastapi import APIRouter
+from pydantic import BaseModel
+from setuptools_scm import get_version
+
+import packit_service
+
+logger = getLogger("packit_service")
+
+router = APIRouter()
+
+
+def get_commit_from_version(version) -> Optional[str]:
+    """
+    Version can look like this:
+        0.76.0.post18+g116edc5
+        0.1.dev1+gc03b1bd.d20230615
+        0.18.0.post4+g28cb117
+        0.45.1.dev2+g3b0fc3b
+
+    The 7 characters after the "+g" is the short version of the git commit hash.
+    """
+    if matches := re.search(r"\+g([A-Za-z0-9]{7})", version):
+        return matches.groups()[0]
+    return None
+
+
+class PackageVersionResponse(BaseModel):
+    commit: Optional[str]
+    version: str
+
+
+@router.get("/system")
+async def get_system_information() -> dict[str, PackageVersionResponse]:
+    """System information"""
+    packages_and_versions = {project: project.__version__ for project in [ogr, specfile, packit]}
+    # packit_service might not be installed (i.e. when running locally)
+    # so it's treated differently
+    packages_and_versions[packit_service] = packit_service.__version__ or get_version(
+        root="..",
+        relative_to=packit_service.__file__,
+    )
+
+    return {
+        project.__name__: PackageVersionResponse(
+            commit=get_commit_from_version(version),
+            version=version,
+        )
+        for project, version in packages_and_versions.items()
+        if version
+    }