Refactor prometheus integration

Move prometheus to SaaS and make it a plugin
Move static callers to use metrics_queue plugin
Change local-docker to support different quay clone dirnames
Change prom_aggregator to use logrus

app.py

@@ -25,7 +25,7 @@ from data.archivedlogs import LogArchive
 from data.userevent import UserEventsBuilderModule
 from data.queue import WorkQueue, MetricQueueReporter
 from util import get_app_url
-from util import prometheus
+from util.saas.prometheus import PrometheusPlugin
 from util.saas.analytics import Analytics
 from util.saas.exceptionlog import Sentry
 from util.names import urn_generator
@@ -168,7 +168,8 @@ Principal(app, use_sessions=False)
 avatar = Avatar(app)
 login_manager = LoginManager(app)
 mail = Mail(app)
-metric_queue = MetricQueue()
+prometheus = PrometheusPlugin(app)
+metric_queue = MetricQueue(prometheus)
 storage = Storage(app, metric_queue)
 userfiles = Userfiles(app, storage)
 log_archive = LogArchive(app, storage)
@@ -208,7 +209,6 @@ if os.path.exists(_v2_key_path):
 else:
   docker_v2_signing_key = RSAKey(key=RSA.generate(2048))
 
-prometheus.init(app.config.get('PROMETHEUS_AGGREGATOR_URL'))
 
 database.configure(app.config)
 model.config.app_config = app.config