fix: make Ansible reruns faster and idempotent

ansible/roles/bootstrap-image-prepull/tasks/main.yml

@@ -1,19 +1,33 @@
 ---
 - name: Pre-pull bootstrap images into containerd
-  command: timeout 180s /usr/local/bin/ctr -n k8s.io images pull {{ item }}
+  shell: |
+    if /usr/local/bin/ctr -n k8s.io images ls -q | grep -Fx -- "{{ item }}" >/dev/null; then
+      echo "already present"
+      exit 0
+    fi
+
+    for attempt in 1 2 3; do
+      if timeout 120s /usr/local/bin/ctr -n k8s.io images pull "{{ item }}"; then
+        echo "pulled image"
+        exit 0
+      fi
+
+      sleep 10
+    done
+
+    exit 1
+  args:
+    executable: /bin/bash
   register: bootstrap_image_pull
   loop: "{{ bootstrap_prepull_images }}"
-  retries: 6
-  delay: 20
-  until: bootstrap_image_pull.rc == 0
-  changed_when: bootstrap_image_pull.rc == 0
+  changed_when: "'pulled image' in bootstrap_image_pull.stdout"
   failed_when: false
 
 - name: Report bootstrap images that did not pre-pull after retries
   debug:
     msg: >-
       Best-effort bootstrap image pre-pull did not complete for {{ item.item }} after
-      {{ item.attempts | default(1) }} attempt(s): {{ item.stderr | default('no stderr') }}
+      3 attempt(s): {{ item.stderr | default('no stderr') }}
   loop: "{{ bootstrap_image_pull.results | default([]) }}"
   loop_control:
     label: "{{ item.item }}"