Merge pull request #174 from stuartmaxwell:healthcheck-app

Healthcheck-app

config/settings.py

@@ -41,6 +41,7 @@
     DEBUGGING_APP_PATH=(str, "this-is-just-a-temporary-debugging-app-path"),
     LOGFIRE_ENVIRONMENT=(str, "dev"),
     BLUESKY_APP_PASSWORD=(str, ""),
+    HEALTHCHECK_PATH=(str, ""),
 )
 
 environ.Env.read_env(Path(BASE_DIR / ".env"))
@@ -76,6 +77,7 @@
     "django.contrib.staticfiles",
     "django.contrib.sitemaps",
     "djpress.apps.DjpressConfig",
+    "healthcheck_app",
     "timezone_converter",
     "markdown_editor",
     "shell",
@@ -325,4 +327,10 @@
 # Logfire
 LOGFIRE_ENVIRONMENT = env("LOGFIRE_ENVIRONMENT")
 logfire.configure(environment=LOGFIRE_ENVIRONMENT)
-logfire.instrument_django()
+logfire.instrument_django(
+    capture_headers=True,
+    excluded_urls="/healthcheck",
+)
+
+# Healthcheck app
+HEALTHCHECK_PATH = env("HEALTHCHECK_PATH")

config/urls.py

@@ -33,6 +33,7 @@
 
 urlpatterns += [
     path(f"{settings.ADMIN_URL}/", admin.site.urls),
+    path("healthcheck/", view=include("healthcheck_app.urls")),
     path("contact/", view=include("contact_form.urls")),
     path("utils/timezones/", view=include("timezone_converter.urls")),
     path("utils/markdown-editor/", view=include("markdown_editor.urls")),

healthcheck_app/__init__.py

@@ -0,0 +1 @@
+"""healthcheck_app package."""

healthcheck_app/apps.py

@@ -0,0 +1,10 @@
+"""App configuration for healthcheck_app."""
+
+from django.apps import AppConfig
+
+
+class HealthcheckAppConfig(AppConfig):
+    """App configuration for the healthcheck app."""
+
+    default_auto_field = "django.db.models.BigAutoField"
+    name = "healthcheck_app"

healthcheck_app/checks.py

@@ -0,0 +1,23 @@
+"""Health checks for the healthcheck_app."""
+
+import logging
+
+from django.db import connections
+from django.db.utils import OperationalError
+
+logger = logging.getLogger(__name__)
+
+
+def check_database() -> tuple[str, str | None]:
+    """Perform the database connectivity check.
+
+    Returns a tuple of the status ('healthy' or 'unhealthy') and an optional error
+    message.
+    """
+    try:
+        connections["default"].cursor()  # You could use a specific database alias if needed
+    except OperationalError as e:
+        logger.debug(f"Health check found an error with the database: {e!s}")
+        return "unhealthy", "Error connecting to the database."
+    else:
+        return "healthy", None

healthcheck_app/urls.py

@@ -0,0 +1,14 @@
+"""URLs for the healthcheck_app."""
+
+from django.conf import settings
+from django.urls import path
+
+from .views import health_check
+
+app_name = "healthcheck_app"
+
+url_path = f"{settings.HEALTHCHECK_PATH}/" if settings.HEALTHCHECK_PATH else ""
+
+urlpatterns = [
+    path(url_path, health_check, name="healthcheck"),
+]

healthcheck_app/views.py

@@ -0,0 +1,47 @@
+"""Views for the healthcheck_app."""
+
+import logging
+
+from django.http import HttpRequest, JsonResponse
+from django.utils import timezone
+
+from healthcheck_app.checks import check_database
+
+logger = logging.getLogger(__name__)
+
+# Checks to perform, with their corresponding check functions
+checks = {
+    "database": check_database,
+}
+
+
+def health_check(_: HttpRequest) -> JsonResponse:
+    """Main function that returns the healthcheck.
+
+    Perform a health check on the application by checking various components.
+    Returns a JsonResponse with the health information of the components.
+    """
+    # Initial health data structure
+    health_data = {
+        "status": "healthy",  # Starts assuming everything is healthy
+        "timestamp": timezone.now().isoformat(),
+        "details": {},
+    }
+
+    # Iterate over the checks and perform them
+    for check_name, check_function in checks.items():
+        status, error = check_function()
+
+        # Update the component's status in the health data
+        health_data["details"][check_name] = {"status": status}
+
+        # If there's an error, add it to the component's data
+        if error:
+            health_data["details"][check_name]["error"] = error
+
+        # If any component is unhealthy, set overall status to 'unhealthy'
+        if status == "unhealthy":
+            health_data["status"] = "unhealthy"
+
+    # Return the JsonResponse with the health data and status code
+    return JsonResponse(health_data)