Added statsd integration into the API

- new client for statsd, follows conventions used elsewhere for configuration
- client wraps underlying library so we can use a config property to send/not send statsd

Added statsd metrics for:
- count of API successful calls SMS/Email
- count of successful task execution for SMS/Email
- count of errors from Client libraries
- timing of API calls to third party clients
- timing of how long messages live on the SQS queue

app/notifications/process_client_response.py

@@ -1,5 +1,7 @@
 import uuid
 from flask import current_app
+
+from app import statsd_client
 from app.dao import notifications_dao
 from app.clients.sms.firetext import get_firetext_responses
 from app.clients.sms.mmg import get_mmg_responses
@@ -67,5 +69,6 @@ def process_sms_client_response(status, reference, client_name):
                                                                                     reference,
                                                                                     notification_status_message))
 
+    statsd_client.incr('notifications.callback.{}.{}'.format(client_name.lower(), notification_statistics_status))
     success = "{} callback succeeded. reference {} updated".format(client_name, reference)
     return success, errors

app/notifications/rest.py

@@ -1,5 +1,5 @@
 from datetime import datetime
-
+import statsd
 import itertools
 from flask import (
     Blueprint,
@@ -12,7 +12,7 @@ from flask import (
 from notifications_utils.recipients import allowed_to_send_to, first_column_heading
 from notifications_utils.template import Template
 from app.clients.email.aws_ses import get_aws_responses
-from app import api_user, encryption, create_uuid, DATETIME_FORMAT, DATE_FORMAT
+from app import api_user, encryption, create_uuid, DATETIME_FORMAT, DATE_FORMAT, statsd_client
 from app.authentication.auth import require_admin
 from app.dao import (
     templates_dao,
@@ -103,6 +103,7 @@ def process_ses_response():
                     )
                 )
 
+            statsd_client.incr('notifications.callback.ses.{}'.format(notification_statistics_status))
             return jsonify(
                 result="success", message="SES callback succeeded"
             ), 200
@@ -374,4 +375,5 @@ def send_notification(notification_type):
             datetime.utcnow().strftime(DATETIME_FORMAT)
         ), queue='email')
 
+    statsd_client.incr('notifications.api.{}'.format(notification_type))
     return jsonify(data={"notification": {"id": notification_id}}), 201