Add MailboxIntegrationTest against a real mailbox instance

wait-for-mailbox.sh

@@ -0,0 +1,21 @@
+#!/bin/bash
+set -e
+
+URL="http://127.0.0.1:8000/status"
+attempt_counter=0
+max_attempts=200 # 10min - CI for mailbox currently takes ~5min
+
+echo "Waiting for mailbox to come online at $URL"
+
+until [[ "$(curl -s -o /dev/null -w '%{http_code}' $URL)" == "401" ]]; do
+  if [ ${attempt_counter} -eq ${max_attempts} ]; then
+    echo "Timed out waiting for mailbox"
+    exit 1
+  fi
+
+  printf '.'
+  attempt_counter=$((attempt_counter + 1))
+  sleep 3
+done
+
+echo "Mailbox started"