Reduce number of image push threads for virtual system

The number of image push threads is set to 1 if the Linux
system is virtual. This change is to accommodate testing parallel
upgrade of a large number of virtual subclouds on the same
subcloud host.

The commit also contains some cosmetic changes.

Test plan:
  - Set up a distributed cloud system that has a large number of
    virtual subclouds for upgrade.
  - Prestage the virtual subclouds.
  - Perform upgrade orchestration of both physical and virtual
    subclouds.

Story: 2009725
Task: 45644
Change-Id: Iecabb412a3ca6426e74f4b2a34b796d701881af4
Signed-off-by: Tee Ngo <tee.ngo@windriver.com>

playbookconfig/src/playbooks/roles/bootstrap/bringup-essential-services/tasks/refresh_local_dns.yml

@@ -65,12 +65,12 @@
   when: mode == 'bootstrap'
 
 - block:
-  - name: restore /etc/hosts file
+  - name: Restore /etc/hosts file
     command: tar -C /etc -xpf {{ restore_data_file }} --transform='s,.*/,,' etc/hosts
     args:
       warn: false
 
-  - name: restore hosts in config permdir
+  - name: Restore hosts in config permdir
     command: >-
       tar -C {{ config_permdir }} -xpf {{ restore_data_file }} --transform='s,.*/,,'
       {{ archive_config_permdir }}/hosts

playbookconfig/src/playbooks/roles/bootstrap/persist-config/tasks/main.yml

@@ -67,7 +67,7 @@
     path: "{{ last_kubernetes_extra_config_file }}"
     state: absent
 
-- name: persist extraArgs and extraVolumes configuration file
+- name: Persist extraArgs and extraVolumes configuration file
   command: >
       mv -f {{ tmp_kubernetes_extra_config_file }}
       {{ last_kubernetes_extra_config_file }}

playbookconfig/src/playbooks/roles/common/push-docker-images/files/push_imported_images_to_local_registry.py

@@ -1,19 +1,21 @@
 #!/usr/bin/python
 #
-# Copyright (c) 2021 Wind River Systems, Inc.
+# Copyright (c) 2021-2022 Wind River Systems, Inc.
 #
 # SPDX-License-Identifier: Apache-2.0
 #
 # This script is used to push images that were previously
 # imported from local image archive(s) to the local registry.
 
+import docker
 import eventlet
+import keyring
+import sys
+import time
+
 eventlet.monkey_patch(os=False)
 from eventlet import greenpool  # noqa: E402
 
-import docker  # noqa: E402
-import time  # noqa: E402
-import keyring  # noqa: E402
 
 MAX_PUSH_THREAD = 5
 REGISTRY_PATTERNS = ['.io', 'docker.elastic.co']
@@ -119,6 +121,11 @@ def push_images(images):
 
 
 if __name__ == '__main__':
+    if len(sys.argv) == 2:
+        if sys.argv[1] != 'physical':
+            MAX_PUSH_THREAD = 1
+            print("Subcloud is virtual. MAX_PUSH_THREAD is set to %d" % MAX_PUSH_THREAD)
+
     image_list = get_list_of_imported_images()
     print("List of imported images: {}".format(image_list))
     start = time.time()

playbookconfig/src/playbooks/roles/common/push-docker-images/tasks/main.yml

@@ -1,6 +1,6 @@
 ---
 #
-# Copyright (c) 2019-2021 Wind River Systems, Inc.
+# Copyright (c) 2019-2022 Wind River Systems, Inc.
 #
 # SPDX-License-Identifier: Apache-2.0
 #
@@ -138,8 +138,12 @@
     download_images_task_name: "Download images and push to local registry"
 
 - block:
+  - name: Retrieve system virtual info
+    command: facter virtual
+    register: virtual_type
+
   - name: Push imported images to local registry
-    script: push_imported_images_to_local_registry.py
+    script: push_imported_images_to_local_registry.py {{ virtual_type.stdout|lower }}
     register: push_imported_images_output
 
   - set_fact: