[fast/warm reboot] improve new image installation code (#877)

* [fast/warm reboot] improve new image installation code

- Allow new_sonic_image being defined as empty string. It causes skipping image installation.
- Rename new_image_location to a generic name.
- Display defined new image url.

Signed-off-by: Ying Xie <[email protected]>

* [fast/warm reboot] allow DUT to stay in the warm/fast reboot target release

This feature is needed in order to test ugprade path. Where we might upgrade from one version
to another, and more. We want the system to stay in target release for next steps.

Signed-off-by: Ying Xie <[email protected]>

* Address review comments, test issues and some minor touch-ups

Signed-off-by: Ying Xie <[email protected]>

* [fast/warm reboot] add knob to clean up old iamges on DUT before warm/fast reboot

When new image is specified for fast/warm reboot. The new image will be installed.
However, if the specified image is already installed on the target DUT, then
sonic_install will fail and fast/warm reboot will reboot into current image.

Add a knob to cleanup old images so that the installing of new image will have a
better chance to succeed.

Signed-off-by: Ying Xie <[email protected]>

* address review issue

Author: yxieca

ansible/roles/test/tasks/advanced-reboot.yml

@@ -106,15 +106,29 @@
         dest: /tmp/ports.json
       delegate_to: "{{ ptf_host }}"
 
+    - debug: msg="Defined new sonic image url is {{ new_sonic_image }}"
+      when: new_sonic_image is defined
+
+    - set_fact:
+        stay_in_target_image:     "{{ stay_in_target_image     | default('false') | bool }}"
+        cleanup_old_sonic_images: "{{ cleanup_old_sonic_images | default('false') | bool }}"
+
     - block:
 
         - name: Save image version
           shell: 'sonic_installer list | grep Current | cut -f2 -d " "'
           register: current_sonic_image
           become: true
+          when: not stay_in_target_image
+
+        - name: Generate temp file name on target device
+          shell: mktemp
+          register: tempfile
 
         - set_fact:
-            new_image_location: '/tmp/new_sonic_image.bin'
+            new_image_location: '{{ tempfile.stdout }}'
+
+        - debug: msg='Setting image file name to {{ new_image_location }}'
 
         - name: Download SONiC image.
           local_action: get_url url={{ new_sonic_image }} dest={{ new_image_location }}
@@ -124,14 +138,24 @@
             src: "{{ new_image_location }}"
             dest: "{{ new_image_location }}"
 
-        - name: Install a new SONiC image if requested
-          shell: sonic_installer install -y {{ new_image_location }}
+        - name: Cleanup sonic images that is not current and/or next
+          shell: sonic_installer cleanup -y
           become: true
+          when: cleanup_old_sonic_images
+
+        - name: 'Setup restoring initial image {{ current_sonic_image }}'
+          shell: /bin/true
+          connection: local
           notify:
-            - restore current image
-            - reboot sonic
+          - restore current image
+          - reboot sonic
+          when: not stay_in_target_image
 
-      when: new_sonic_image is defined
+        - name: Installing new SONiC image
+          shell: sonic_installer install -y {{ new_image_location }}
+          become: true
+
+      when: new_sonic_image | default('') | length > 0
 
     - include: ptf_runner.yml
       vars: