Added health checks with flask-healthz

Resolves: #352

Signed-off-by: Riccardi Dalexis <[email protected]>

mirrormanager2/app.py

@@ -29,6 +29,7 @@
 
 import flask
 from flask_admin import Admin
+from flask_healthz import healthz
 from flask_oidc import OpenIDConnect
 from sqlalchemy.orm import configure_mappers
 
@@ -130,6 +131,8 @@ def create_app(config=None):
     app.register_blueprint(api_views, url_prefix="/api")
     from mirrormanager2.xml_rpc import XMLRPC
 
+    app.register_blueprint(healthz, url_prefix="/healthz")
+
     XMLRPC.connect(app, "/xmlrpc")
 
     return app

mirrormanager2/default_config.py

@@ -195,3 +195,8 @@
 UMDL_PREFIX = ""
 
 UMDL_MASTER_DIRECTORIES = []
+
+HEALTHZ = {
+    "live": "mirrormanager2.health_checks.liveness",
+    "ready": "mirrormanager2.health_checks.readiness",
+}

mirrormanager2/health_checks.py

@@ -0,0 +1,15 @@
+from flask_healthz import HealthError
+from sqlalchemy.exc import OperationalError
+
+from mirrormanager2.database import DB
+
+
+def liveness():
+    pass
+
+
+def readiness():
+    try:
+        DB.manager.get_status()
+    except OperationalError as err:
+        raise HealthError("Can't connect to the database") from err

pyproject.toml

@@ -47,6 +47,7 @@ python = "^3.9"
 email-validator = ">=1.1.3"
 flask = "^2.2.3 || ^3.0.0"
 flask-admin = "^1.6.0"
+flask-healthz = "^1.0.0"
 flask-oidc = "^2.0.0"
 flask-xml-rpc-re = "^0.1.4"
 flask-wtf = "^1.1.1"

tests/test_health_checks.py

@@ -0,0 +1,24 @@
+import os
+
+from mirrormanager2.app import create_app
+
+
+def test_healthz_readiness_ok(client):
+    result = client.get("/healthz/ready")
+    assert result.status_code == 200
+
+
+def test_healthz_readiness_not_ok(app):
+    here = os.path.dirname(os.path.abspath(__file__))
+    app = create_app(
+        {
+            "TESTING": True,
+            # Set fake database
+            "SQLALCHEMY_DATABASE_URI": "sqlite:///I/don't/exist.sqlite",
+            "OIDC_CLIENT_SECRETS": os.path.join(here, "client_secrets.json"),
+            "USE_FEDORA_MESSAGING": False,
+        }
+    )
+    client = app.test_client()
+    result = client.get("/healthz/ready")
+    assert result.status_code != 200