fix: improve image pull verification and fix registries_to_login type error

- Check if image exists before pull to determine if force pull is needed
- Use docker images command to verify image exists locally (more reliable)
- Fix registries_to_login Jinja2 template to ensure it's always a list
- Add better error messages when image pull fails
- Only tag image if it was successfully verified to exist

deployment/ansible/playbooks/deploy-image.yml

@@ -136,12 +136,34 @@
           - "Registry accessible: {{ registry_accessible | default('unknown') }}"
       when: registry_accessible is defined and registry_accessible == 'true'
 
-    - name: Pull Docker image
+    - name: Check if image already exists locally
+      ansible.builtin.shell: |
+        docker images --format "{{ '{{' }}.Repository{{ '}}' }}:{{ '{{' }}.Tag{{ '}}' }}" | grep -E "^{{ deploy_image | regex_escape }}$" || echo "NOT_FOUND"
+      register: image_exists_before_pull
+      when: registry_accessible is defined and registry_accessible == 'true'
+      changed_when: false
+      failed_when: false
+
+    - name: Pull Docker image (force pull if not exists locally)
+      community.docker.docker_image:
+        name: "{{ deploy_image }}"
+        source: pull
+        pull: always
+      when: 
+        - registry_accessible is defined and registry_accessible == 'true'
+        - image_exists_before_pull.stdout | default('') == 'NOT_FOUND'
+      register: image_pull_result
+      ignore_errors: yes
+      failed_when: false
+
+    - name: Pull Docker image (if already exists, just verify)
       community.docker.docker_image:
         name: "{{ deploy_image }}"
         source: pull
         pull: true
-      when: registry_accessible is defined and registry_accessible == 'true'
+      when: 
+        - registry_accessible is defined and registry_accessible == 'true'
+        - image_exists_before_pull.stdout | default('') != 'NOT_FOUND'
       register: image_pull_result
       ignore_errors: yes
       failed_when: false
@@ -162,12 +184,35 @@
       ignore_errors: yes
       failed_when: false
 
+    - name: Check if image exists by inspecting docker images
+      ansible.builtin.shell: |
+        docker images --format "{{ '{{' }}.Repository{{ '}}' }}:{{ '{{' }}.Tag{{ '}}' }}" | grep -E "^{{ deploy_image | regex_escape }}$" || echo "NOT_FOUND"
+      register: image_check
+      when: registry_accessible is defined and registry_accessible == 'true'
+      changed_when: false
+      failed_when: false
+
+    - name: Display image verification results
+      ansible.builtin.debug:
+        msg:
+          - "Image info result: {{ image_info | default('not executed') }}"
+          - "Image check result: {{ image_check.stdout | default('not executed') }}"
+          - "Image exists: {{ 'YES' if (image_check.stdout | default('') != 'NOT_FOUND' and image_check.stdout | default('') != '') else 'NO' }}"
+      when: registry_accessible is defined and registry_accessible == 'true'
+
     - name: Fail if image was not pulled successfully
       ansible.builtin.fail:
-        msg: "Failed to pull image {{ deploy_image }} from registry. Image does not exist locally."
+        msg: |
+          Failed to pull image {{ deploy_image }} from registry.
+          The image does not exist locally after pull attempt.
+          Pull result: changed={{ image_pull_result.changed | default(false) }}, failed={{ image_pull_result.failed | default(false) }}
+          Please check:
+          1. Does the image exist in {{ source_registry }}?
+          2. Are registry credentials correct?
+          3. Is the registry accessible?
       when: 
         - registry_accessible is defined and registry_accessible == 'true'
-        - image_info.failed | default(true) | bool
+        - (image_check.stdout | default('') == 'NOT_FOUND' or image_check.stdout | default('') == '')
 
     - name: Tag image for local registry (if source and local registry differ)
       community.docker.docker_image:
@@ -177,7 +222,9 @@
         source: local
       when: 
         - source_registry != local_registry
-        - image_info.failed is not defined or not image_info.failed
+        - image_check.stdout is defined
+        - image_check.stdout != 'NOT_FOUND'
+        - image_check.stdout != ''
       register: image_tag_result
 
     - name: Push image to local registry (if source and local registry differ)
@@ -311,9 +358,11 @@
             {%- else -%}
               {%- set reg_list = [local_registry] -%}
             {%- endif -%}
-            {{ reg_list | unique | list }}
+            {%- set final_list = reg_list | unique | list -%}
+            {{ final_list }}
           {%- else -%}
-            {{ [docker_registry] }}
+            {%- set default_list = [docker_registry | default('localhost:5000')] -%}
+            {{ default_list }}
           {%- endif -%}
 
     - name: Login to all Docker registries before compose up