From 90017aa4f2089a365bffce1249df6ce1c50d8846 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=A0t=C4=9Bp=C3=A1n=20Tomsa?= <stomsa@redhat.com>
Date: Mon, 16 Dec 2024 14:43:58 +0100
Subject: [PATCH] feat: Check connection

In case of DNS failure. The DNS is queried, then a connection is established to the resolved IP. If resolving fails, a hard-coded IP is tried for production or staging. In case of either failure, DNS query for a public CloudFlare URL one.one.one.one and its IP 1.1.1.1 is tried.
---
 insights/client/connection.py | 64 ++++++++++++++++++++++++++++++++++-
 insights/client/constants.py  |  4 +++
 2 files changed, 67 insertions(+), 1 deletion(-)

diff --git a/insights/client/connection.py b/insights/client/connection.py
index a3dfd75fbb..751a00d52d 100644
--- a/insights/client/connection.py
+++ b/insights/client/connection.py
@@ -4,6 +4,7 @@
 from __future__ import print_function
 from __future__ import absolute_import
 import requests
+import socket
 import os
 import six
 import json
@@ -18,10 +19,12 @@
 try:
     # python 2
     from urlparse import urlparse
+    from urlparse import urlunparse
     from urllib import quote
 except ImportError:
     # python 3
     from urllib.parse import urlparse
+    from urllib.parse import urlunparse
     from urllib.parse import quote
 from .utilities import (determine_hostname,
                         generate_machine_id,
@@ -74,6 +77,26 @@ def _api_request_failed(exception, message='The Insights API could not be reache
         logger.error(message)
 
 
+def _is_dns_error(exception):
+    while exception:
+        if isinstance(exception, socket.gaierror):
+            return True
+
+        exception = exception.__context__
+
+    return False
+
+
+def _fallback_ip(hostname):
+    if hostname.endswith("redhat.com"):
+        if hostname.endswith("stage.redhat.com"):
+            return constants.insights_ip_stage
+        else:
+            return constants.insights_ip_prod
+    else:
+        return None
+
+
 class InsightsConnection(object):
 
     """
@@ -369,7 +392,6 @@ def _legacy_test_urls(self, url, method):
                 if test_req.status_code in (200, 201):
                     return True
                 else:
-                    logger.error("      Failed.")
                     return False
             except REQUEST_FAILED_EXCEPTIONS as exc:
                 last_ex = exc
@@ -492,6 +514,22 @@ def test_connection(self, rc=0):
         logger.info("Running Connection Tests...")
         logger.info("")
 
+        # base_url_hostname = urlparse(self.base_url).hostname
+        # if base_url_hostname.endswith("redhat.com"):
+        #     if base_url_hostname.endswith("stage.redhat.com"):
+        #         base_url_ip = constants.insights_ip_stage
+        #     else:
+        #         base_url_ip = constants.insights_ip_prod
+        # else:
+        #     base_url_ip = None
+        #
+        # resolved_base_url_ip, success_base_url_ip = self._test_connection(base_url_hostname, base_url_ip)
+        # if not resolved_base_url_ip or not success_base_url_ip:
+        #     resolved_fallback_ip, success_fallback_ip = self._test_connection("www.redhat.com", constants.stable_public_ip)
+        #     logger.debug("dns %s, conn %s", resolved_fallback_ip, success_fallback_ip)
+        #     return False
+
+        last_ex = None
         for description, url, method in [
             ("Uploading a file to Ingress", self.upload_url, "POST"),
             ("Getting hosts from Inventory", self.inventory_url + "/hosts", "GET"),
@@ -520,6 +558,30 @@ def test_connection(self, rc=0):
         logger.error("    Additional information may be in %s" % self.config.logging_file)
         logger.error("")
 
+        if _is_dns_error(last_ex):
+            parsed_url = urlparse(url)
+            logger.error("  Could not resolve %s.", parsed_url.hostname)
+            fallback = [constants.stable_public_url, constants.stable_public_ip]
+            ip = _fallback_ip(parsed_url.hostname)
+            if ip:
+                fallback = [ip] + fallback
+
+            for fallback_url in fallback:
+                parsed_ip_url = urlunparse((parsed_url.scheme, fallback_url, "/", "", "", ""))
+                try:
+                    logger.info('    Testing %s', parsed_ip_url)
+                    log_prefix = "      "
+                    log_level = NETWORK if self.config.verbose else logging.DEBUG
+                    self.get(parsed_ip_url, log_prefix=log_prefix, log_level=log_level, verify=False)
+                except REQUEST_FAILED_EXCEPTIONS as exc:
+                    logger.debug("      Caught %s: %s", type(exc).__name__, exc)
+                    logger.error("      Failed.")
+                else:
+                    logger.info("    SUCCESS.")
+                    break
+            else:
+                logger.info("    FAILED.")
+
         return 1
 
     def handle_fail_rcs(self, req):
diff --git a/insights/client/constants.py b/insights/client/constants.py
index 688878ad4a..6087096a90 100644
--- a/insights/client/constants.py
+++ b/insights/client/constants.py
@@ -90,3 +90,7 @@ class InsightsConstants(object):
     rhsm_facts_file = os.path.join(os.sep, 'etc', 'rhsm', 'facts', 'insights-client.facts')
     # In MB
     archive_filesize_max = 100
+    insights_ip_prod = "23.37.45.238"
+    insights_ip_stage = "23.53.5.13"
+    stable_public_url = "one.one.one.one"  # Public CloudFlare DNS
+    stable_public_ip = "1.1.1.1"  # Public CloudFlare DNS