Add health endpoint

Author: bonnetn

api_server/main.py

@@ -1,15 +1,15 @@
 #!/usr/bin/env python3
+import os
 import sys
 
 import connexion
-import os
 
 from config import CONFIGURATION, TEST_CONFIGURATION
-from src.interface_adapter.sql.account_type_repository import AccountTypeSQLRepository
 from src.interface_adapter.elasticsearch.repository import ElasticSearchRepository
 from src.interface_adapter.http_api.account import AccountHandler
 from src.interface_adapter.http_api.account_type import AccountTypeHandler
 from src.interface_adapter.http_api.device import DeviceHandler
+from src.interface_adapter.http_api.health import HealthHandler
 from src.interface_adapter.http_api.member import MemberHandler
 from src.interface_adapter.http_api.payment_method import PaymentMethodHandler
 from src.interface_adapter.http_api.port import PortHandler
@@ -19,27 +19,30 @@
 from src.interface_adapter.http_api.temporary_account import TemporaryAccountHandler
 from src.interface_adapter.http_api.transaction import TransactionHandler
 from src.interface_adapter.snmp.switch_network_manager import SwitchSNMPNetworkManager
+from src.interface_adapter.sql.account_repository import AccountSQLRepository
+from src.interface_adapter.sql.account_type_repository import AccountTypeSQLRepository
 from src.interface_adapter.sql.device_repository import DeviceSQLRepository
 from src.interface_adapter.sql.member_repository import MemberSQLRepository
 from src.interface_adapter.sql.model.database import Database
 from src.interface_adapter.sql.money_repository import MoneySQLRepository
 from src.interface_adapter.sql.network_object_repository import NetworkObjectSQLRepository
 from src.interface_adapter.sql.payment_method_repository import PaymentMethodSQLRepository
-from src.interface_adapter.sql.room_repository import RoomSQLRepository
-from src.interface_adapter.sql.account_repository import AccountSQLRepository
+from src.interface_adapter.sql.ping_repository import PingSQLRepository
 from src.interface_adapter.sql.product_repository import ProductSQLRepository
+from src.interface_adapter.sql.room_repository import RoomSQLRepository
 from src.interface_adapter.sql.transaction_repository import TransactionSQLRepository
 from src.resolver import ADHResolver
+from src.use_case.account_manager import AccountManager
+from src.use_case.account_type_manager import AccountTypeManager
 from src.use_case.device_manager import DeviceManager
+from src.use_case.health_manager import HealthManager
 from src.use_case.member_manager import MemberManager
 from src.use_case.payment_method_manager import PaymentMethodManager
 from src.use_case.port_manager import PortManager
+from src.use_case.product_manager import ProductManager
 from src.use_case.room_manager import RoomManager
 from src.use_case.switch_manager import SwitchManager
-from src.use_case.account_manager import AccountManager
-from src.use_case.product_manager import ProductManager
 from src.use_case.transaction_manager import TransactionManager
-from src.use_case.account_type_manager import AccountTypeManager
 
 
 def init(testing=True):
@@ -54,6 +57,7 @@ def init(testing=True):
     Database.init_db(configuration.DATABASE, testing=testing)
 
     # Repositories:
+    ping_repository = PingSQLRepository()
     member_sql_repository = MemberSQLRepository()
     network_object_sql_repository = NetworkObjectSQLRepository()
     device_sql_repository = DeviceSQLRepository()
@@ -68,6 +72,7 @@ def init(testing=True):
     account_type_sql_repository = AccountTypeSQLRepository()
 
     # Managers
+    health_manager = HealthManager(ping_repository)
     switch_manager = SwitchManager(
         switch_repository=network_object_sql_repository,
     )
@@ -110,6 +115,7 @@ def init(testing=True):
     )
 
     # HTTP Handlers:
+    health_handler = HealthHandler(health_manager)
     transaction_handler = TransactionHandler(transaction_manager)
     member_handler = MemberHandler(member_manager)
     device_handler = DeviceHandler(device_manager)
@@ -130,6 +136,7 @@ def init(testing=True):
     app.add_api('swagger.yaml',
                 # resolver=RestyResolver('src.interface_adapter.http_api'),
                 resolver=ADHResolver({
+                    'health': health_handler,
                     'transaction': transaction_handler,
                     'member': member_handler,
                     'device': device_handler,

api_server/src/interface_adapter/http_api/health.py

@@ -0,0 +1,22 @@
+from connexion import NoContent
+
+from src.interface_adapter.http_api.decorator.with_context import with_context
+from src.interface_adapter.sql.decorator.sql_session import require_sql
+from src.use_case.health_manager import HealthManager
+from src.util.context import log_extra
+from src.util.log import LOG
+
+
+class HealthHandler:
+    def __init__(self, health_manager: HealthManager):
+        self.health_manager = health_manager
+
+    @with_context
+    @require_sql
+    def health(self, ctx):
+        LOG.debug("http_health_called", extra=log_extra(ctx))
+
+        if self.health_manager.is_healthy(ctx):
+            return "OK", 200
+        else:
+            return "FAILURE", 503

api_server/src/interface_adapter/sql/ping_repository.py

@@ -0,0 +1,22 @@
+from sqlalchemy.exc import SQLAlchemyError
+
+from src.constants import CTX_SQL_SESSION
+from src.use_case.interface.ping_repository import PingRepository
+from src.util.context import log_extra
+from src.util.log import LOG
+
+
+class PingSQLRepository(PingRepository):
+    def ping(self, ctx) -> bool:
+        LOG.debug("sql_ping", extra=log_extra(ctx))
+
+        s = ctx.get(CTX_SQL_SESSION)
+        try:
+            result = s.execute('SELECT 42').fetchall()
+            if 1 != len(result):
+                return False
+
+            return [('42', 42)] == result[0].items()
+
+        except SQLAlchemyError:
+            return False

api_server/src/use_case/health_manager.py

@@ -0,0 +1,23 @@
+from src.use_case.interface.ping_repository import PingRepository
+from src.util.context import log_extra
+from src.util.log import LOG
+
+
+class HealthManager:
+    """
+    Response to health requests.
+    """
+
+    def __init__(self, repository: PingRepository):
+        self.health_repository = repository
+
+    def is_healthy(self, ctx) -> bool:
+        db_health = self.health_repository.ping(ctx)
+        if not db_health:
+            LOG.error("health_check_db_not_healthy", extra=log_extra(ctx))
+            return False
+
+        # TODO: add more health checks?
+
+        LOG.info("health_check_success", extra=log_extra(ctx))
+        return True

api_server/src/use_case/interface/ping_repository.py

@@ -0,0 +1,11 @@
+import abc
+
+
+class PingRepository(metaclass=abc.ABCMeta):
+    """
+    Abstract interface to get the health of the DB.
+    """
+
+    @abc.abstractmethod
+    def ping(self, ctx) -> bool:
+        pass  # pragma: no cover

openapi/spec.yaml

@@ -12,6 +12,15 @@ info:
 servers:
   - url: /api
 paths:
+  /health/:
+    get:
+      operationId: health
+      responses:
+        200:
+          description: ADH6 is alive!
+        503:
+          description: Database is down.
+      summary: Health endpoint, query this with zabbix to know if ADH6 is running or not.
   /account/:
     get:
       parameters: