[CI] Move requests and openstack imports to where they are used.

Moving the imports of openstack and requests to the place where they are
used allows for running the script locally without openstack or S3
access.
Only if one attempts downloads or uploads, the imports become necessary.

Author: hageboeck

.github/workflows/root-ci-config/build_root.py

@@ -24,7 +24,6 @@
 import time
 
 import build_utils
-import openstack
 from build_utils import (
     calc_options_hash,
     die,
@@ -38,12 +37,6 @@
 S3CONTAINER = 'ROOT-build-artifacts'  # Used for uploads
 S3URL = 'https://s3.cern.ch/swift/v1/' + S3CONTAINER  # Used for downloads
 
-try:
-    CONNECTION = openstack.connect(cloud='envvars')
-except Exception as exc:
-    print("Failed to open the S3 connection:", exc, file=sys.stderr)
-    CONNECTION = None
-
 WINDOWS = (os.name == 'nt')
 WORKDIR = (os.environ['HOME'] + '/ROOT-CI') if not WINDOWS else 'C:/ROOT-CI'
 COMPRESSIONLEVEL = 6 if not WINDOWS else 1
@@ -346,6 +339,14 @@ def archive_and_upload(archive_name, prefix):
         targz.add("src")
         targz.add("build")
 
+    try:
+        import openstack
+        CONNECTION = openstack.connect(cloud='envvars')
+    except Exception as exc:
+        print("Failed to open the S3 connection:", exc, file=sys.stderr)
+        CONNECTION = None
+
+
     upload_file(
         connection=CONNECTION,
         container=S3CONTAINER,

.github/workflows/root-ci-config/build_utils.py

@@ -14,9 +14,6 @@
 from shutil import which
 from typing import Callable, Dict
 
-from openstack.connection import Connection
-from requests import get
-
 
 def is_macos():
     return 'Darwin' == platform.system()
@@ -238,7 +235,7 @@ def calc_options_hash(options: str) -> str:
         options_and_defines += sp_result.stdout
     return sha1(options_and_defines.encode('utf-8')).hexdigest()
 
-def upload_file(connection: Connection, container: str, dest_object: str, src_file: str) -> None:
+def upload_file(connection, container: str, dest_object: str, src_file: str) -> None:
     print(f"Attempting to upload {src_file} to {dest_object}")
 
     if not os.path.exists(src_file):
@@ -297,6 +294,7 @@ def download_latest(url: str, prefix: str, destination: str) -> str:
     """Downloads latest build artifact starting with <prefix>,
        and returns the file path to the downloaded file and shell_log."""
 
+    from requests import get
     # https://docs.openstack.org/api-ref/object-store/#show-container-details-and-list-objects
     with get(f"{url}/?prefix={prefix}&format=json", timeout=20) as req:
         if req.status_code == HTTPStatus.NO_CONTENT or req.content == b'[]':