Switch to elasticsearch 7.x

There have been frequent 404 errors attempting to access the
artifacts.elastic.co archive for 5.x.

This also adds some tenacity retries to tests that apear to
be racey.

Change-Id: I04529e8d5584e006c090e790e9903592609343ee

snapcraft.yaml

@@ -1571,7 +1571,7 @@ parts:
       cat $SNAPCRAFT_PROJECT_DIR/filebeat.pgp.key | apt-key add -
       cat $SNAPCRAFT_PROJECT_DIR/telegraf.pgp.key | apt-key add -
       apt-get install apt-transport-https
-      echo 'deb https://artifacts.elastic.co/packages/5.x/apt stable main' > /etc/apt/sources.list.d/elastic-5.x.list
+      echo 'deb https://artifacts.elastic.co/packages/7.x/apt stable main' > /etc/apt/sources.list.d/elastic-7.x.list
       echo 'deb http://ppa.launchpad.net/telegraf-devs/ppa/ubuntu bionic main' > /etc/apt/sources.list.d/telegraf.x.list
       # this needs to be re-worked in order to be built in-place
       echo 'deb http://ppa.launchpad.net/nikolay.vinogradov/nrpe-root/ubuntu bionic main' > /etc/apt/sources.list.d/nrpe-root.list

tests/test_basic.py

@@ -20,6 +20,7 @@ import unittest
 
 sys.path.append(os.getcwd())
 
+import tenacity
 from tests.framework import Framework  # noqa E402
 
 
@@ -62,8 +63,14 @@ class TestBasics(Framework):
         )
         self.verify_instance_networking(self._localhost, instance_name)
 
-        # The Horizon Dashboard should function
-        self.verify_gui(self._localhost)
+        # Ensure horizon has enough time to start
+        @tenacity.retry(wait=tenacity.wait_fixed(1),
+                        stop=tenacity.stop_after_attempt(10))
+        def wait_verify_gui():
+            # The Horizon Dashboard should function
+            self.verify_gui(self._localhost)
+
+        wait_verify_gui()
 
         # Verify that we can uninstall the snap cleanly, and that the
         # ovs bridge goes away.

tests/test_cluster.py

@@ -131,7 +131,14 @@ class TestCluster(Framework):
 
         self.assertTrue(ip)
 
-        control_host.check_call(['ping', '-c10', '-w11', ip])
+        # Ensure instance has enough time to initialize
+        @tenacity.retry(wait=tenacity.wait_fixed(1),
+                        stop=tenacity.stop_after_attempt(10))
+        def wait_ping():
+            control_host.check_call(['ping', '-c10', '-w11', ip])
+
+        wait_ping()
+
         self.passed = True