SERVER-78250 Implement fallback for releases.yml

Author: Tausif Rahman

buildscripts/resmokelib/multiversionconstants.py

@@ -5,6 +5,7 @@
 import requests
 
 import structlog
+import buildscripts.resmokelib.config as _config
 
 from buildscripts.resmokelib.multiversion.multiversion_service import (
     MongoReleases, MongoVersion, MultiversionService, MONGO_VERSION_YAML, RELEASES_YAML)
@@ -38,9 +39,20 @@ def generate_mongo_version_file():
 
 def generate_releases_file():
     """Generate the releases constants file."""
-    # Copy the 'releases.yml' file from the source tree.
-    with open(RELEASES_YAML, "wb") as file:
-        file.write(requests.get(MASTER_RELEASES_FILE).content)
+    try:
+        # Get the latest releases.yml from github
+        with open(RELEASES_YAML, "wb") as file:
+            file.write(requests.get(MASTER_RELEASES_FILE).content)
+    except Exception as exc:
+        LOGGER.warning(f"Could not get releases.yml file: {MASTER_RELEASES_FILE}")
+
+        # If this fails in CI we want to be aware and fix this
+        if _config.EVERGREEN_TASK_ID:
+            raise exc
+
+        # Fallback to the current releases.yml
+        releases_yaml_path = os.path.join("src", "mongo", "util", "version", "releases.yml")
+        shutil.copyfile(releases_yaml_path, RELEASES_YAML)
 
 
 def in_git_root_dir():