Guard against async creation of nodes DB

When a new CouchDB comes up the network interface is live before the
nodes database is created. We could incorporate a check for the
existence of the database into the readinessProbe on the CouchDB
container, but we can also simply be defensive here.

Author: kocolosk

mem3_helper.py

@@ -35,6 +35,10 @@ def connect_the_dots(names, retries=5):
             doc = {}
             try:
                 r = requests.put(uri, data = json.dumps(doc))
+                if r.status_code == 404:
+                    print('CouchDB nodes DB does not exist yet')
+                    time.sleep(5)
+                    connect_the_dots(names, retries - 1)
                 print(name, r.status_code)
             except requests.exceptions.ConnectionError:
                 print('CouchDB admin port not up yet')