Retry requests to artifacts API from CI jobs (elastic#10675)

Retry forever if the artifacts API is not available, and assume it will
come back at some point. If it doesn't come back, the job would fail in
any case by timeout.

.buildkite/scripts/find_oldest_supported_version.py

@@ -2,14 +2,27 @@
 import argparse
 import requests
 import sys
-import yaml
 import unittest
+import yaml
 
-VERSION_URL = "https://artifacts-api.elastic.co/v1/versions?x-elastic-no-kpi=true"
+from requests.adapters import HTTPAdapter, Retry
+
+ARTIFACTS_URL = "https://artifacts-api.elastic.co"
+VERSION_URL = ARTIFACTS_URL + "/v1/versions?x-elastic-no-kpi=true"
 
 
 def fetch_version():
-    return requests.get(VERSION_URL).json()
+    # Retry forever on connection or 500 errors, assume the artifacts API
+    # will come back. If it doesn't come back we cannot continue executing
+    # jobs in any case.
+    retries = Retry(
+        total=None,
+        backoff_factor=0.5,
+        status_forcelist=[500, 502, 503, 504],
+    )
+    session = requests.Session()
+    session.mount(ARTIFACTS_URL, HTTPAdapter(max_retries=retries))
+    return session.get(VERSION_URL).json()
 
 
 def find_oldest_supported_version(kibana_version_condition: str) -> str:

.buildkite/scripts/trigger_integrations_in_parallel.sh

@@ -50,6 +50,7 @@ for package in ${PACKAGE_LIST}; do
     - label: "Check integrations ${package}"
       key: "test-integrations-${package}"
       command: ".buildkite/scripts/test_one_package.sh ${package} ${from} ${to}"
+      timeout_in_minutes: 240
       agents:
         provider: gcp
         image: ${IMAGE_UBUNTU_X86_64}