Merge pull request #3017 from alphagov/cbc-proxy-canary

Add task to send canary to cbc proxy

app/celery/scheduled_tasks.py

@@ -1,3 +1,5 @@
+import uuid
+
 from datetime import (
     datetime,
     timedelta
@@ -8,7 +10,7 @@ from notifications_utils.statsd_decorators import statsd
 from sqlalchemy import and_
 from sqlalchemy.exc import SQLAlchemyError
 
-from app import notify_celery, zendesk_client
+from app import cbc_proxy_client, notify_celery, zendesk_client
 from app.celery.tasks import (
     process_job,
     get_recipient_csv_and_template_and_sender_id,
@@ -291,3 +293,11 @@ def check_for_services_with_high_failure_rates_or_sending_to_tv_numbers():
                 message=message,
                 ticket_type=zendesk_client.TYPE_INCIDENT
             )
+
+
+@notify_celery.task(name='send-canary-to-cbc-proxy')
+def send_canary_to_cbc_proxy():
+    identifier = str(uuid.uuid4())
+    message = f"Sending a canary message to CBC proxy with ID {identifier}"
+    current_app.logger.info(message)
+    cbc_proxy_client.send_canary(identifier)

app/clients/cbc_proxy.py

@@ -26,6 +26,12 @@ class CBCProxyNoopClient:
     def init_app(self, app):
         pass
 
+    def send_canary(
+        self,
+        identifier,
+    ):
+        pass
+
     def create_and_send_broadcast(
         self,
         identifier, headline, description, areas
@@ -57,6 +63,26 @@ class CBCProxyClient:
             aws_secret_access_key=app.config['CBC_PROXY_AWS_SECRET_ACCESS_KEY'],
         )
 
+    def send_canary(
+        self,
+        identifier,
+    ):
+        payload_bytes = bytes(json.dumps({
+            'identifier': identifier,
+        }), encoding='utf8')
+
+        result = self._lambda_client.invoke(
+            FunctionName='canary',
+            InvocationType='RequestResponse',
+            Payload=payload_bytes,
+        )
+
+        if result['StatusCode'] > 299:
+            raise Exception('Could not invoke lambda')
+
+        if 'FunctionError' in result:
+            raise Exception('Function exited with unhandled exception')
+
     def create_and_send_broadcast(
         self,
         identifier, headline, description, areas,

app/config.py

@@ -303,6 +303,11 @@ class Config(object):
             'schedule': crontab(hour=23, minute=00),
             'options': {'queue': QueueNames.PERIODIC}
         },
+        'send-canary-to-cbc-proxy': {
+            'task': 'send-canary-to-cbc-proxy',
+            'schedule': timedelta(minutes=5),
+            'options': {'queue': QueueNames.PERIODIC}
+        },
     }
     CELERY_QUEUES = []
 

tests/app/celery/test_scheduled_tasks.py

@@ -1,3 +1,4 @@
+import uuid
 from datetime import datetime, timedelta
 from unittest.mock import call
 
@@ -555,3 +556,22 @@ def test_check_for_services_with_high_failure_rates_or_sending_to_tv_numbers(
         subject="[test] High failure rates for sms spotted for services",
         ticket_type='incident'
     )
+
+
+def test_send_canary_to_cbc_proxy_invokes_cbc_proxy_client(
+    mocker,
+):
+    mock_send_canary = mocker.patch(
+        'app.cbc_proxy_client.send_canary',
+    )
+
+    scheduled_tasks.send_canary_to_cbc_proxy()
+
+    mock_send_canary.assert_called
+    # the 0th argument of the call to send_canary
+    identifier = mock_send_canary.mock_calls[0][1][0]
+
+    try:
+        uuid.UUID(identifier)
+    except BaseException:
+        pytest.fail(f"{identifier} is not a valid uuid")

tests/app/clients/test_cbc_proxy.py

@@ -1,4 +1,5 @@
 import json
+import uuid
 
 import pytest
 
@@ -165,3 +166,88 @@ def test_cbc_proxy_create_and_send_handles_function_error(mocker, cbc_proxy):
         InvocationType='RequestResponse',
         Payload=mocker.ANY,
     )
+
+
+def test_cbc_proxy_send_canary_invokes_function(mocker, cbc_proxy):
+    identifier = str(uuid.uuid4())
+
+    ld_client_mock = mocker.patch.object(
+        cbc_proxy,
+        '_lambda_client',
+        create=True,
+    )
+
+    ld_client_mock.invoke.return_value = {
+        'StatusCode': 200,
+    }
+
+    cbc_proxy.send_canary(
+        identifier=identifier,
+    )
+
+    ld_client_mock.invoke.assert_called_once_with(
+        FunctionName='canary',
+        InvocationType='RequestResponse',
+        Payload=mocker.ANY,
+    )
+
+    kwargs = ld_client_mock.invoke.mock_calls[0][-1]
+    payload_bytes = kwargs['Payload']
+    payload = json.loads(payload_bytes)
+
+    assert payload['identifier'] == identifier
+
+
+def test_cbc_proxy_send_canary_handles_invoke_error(mocker, cbc_proxy):
+    identifier = str(uuid.uuid4())
+
+    ld_client_mock = mocker.patch.object(
+        cbc_proxy,
+        '_lambda_client',
+        create=True,
+    )
+
+    ld_client_mock.invoke.return_value = {
+        'StatusCode': 400,
+    }
+
+    with pytest.raises(Exception) as e:
+        cbc_proxy.send_canary(
+            identifier=identifier,
+        )
+
+        assert e.match('Function exited with unhandled exception')
+
+    ld_client_mock.invoke.assert_called_once_with(
+        FunctionName='canary',
+        InvocationType='RequestResponse',
+        Payload=mocker.ANY,
+    )
+
+
+def test_cbc_proxy_send_canary_handles_function_error(mocker, cbc_proxy):
+    identifier = str(uuid.uuid4())
+
+    ld_client_mock = mocker.patch.object(
+        cbc_proxy,
+        '_lambda_client',
+        create=True,
+    )
+
+    ld_client_mock.invoke.return_value = {
+        'StatusCode': 200,
+        'FunctionError': 'something',
+    }
+
+    with pytest.raises(Exception) as e:
+        cbc_proxy.send_canary(
+            identifier=identifier,
+        )
+
+        assert e.match('Could not invoke lambda')
+
+    ld_client_mock.invoke.assert_called_once_with(
+        FunctionName='canary',
+        InvocationType='RequestResponse',
+        Payload=mocker.ANY,
+    )