[fast/warm reboot] improve new image installation code

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: