Makes buildah retries more verbose

As we found that buildah may fail with litterary no output we need
to be sure that retries happen with more verbosity, so we can identify
what caused the failure.

Change-Id: I6ed857a827d129d99b5826d6c3afbc9d7c71d501
Example: http://logs.openstack.org/60/636860/7/check/tripleo-ci-fedora-28-standalone/2565b12/logs/undercloud/var/log/tripleo-container-image-prepare.log.txt.gz

tasks/yum_update_buildah.yml

@@ -34,24 +34,42 @@
     chdir: "{{ yum_repos_dir_path }}"
   register: file_repos
 
-- name: Run yum_update.sh
-  command: >
-    buildah run
-      --volume {{ yum_update.path }}:/tmp/yum_update.sh
-      --volume {{ yum_repos_dir_path }}:/etc/yum.repos.d
-      {% for repo in file_repos.stdout_lines %}
-        {% if repo|exists %}
-          --volume {{ repo }}:{{ repo }}
-        {% endif %}
-      {% endfor %}
-      --user root
-      --net host
-      {{ from_image }}
-      /tmp/yum_update.sh "{{ update_repo }}"
-  retries: 3
-  delay: 3
-  register: result
-  until: result.rc == 0
+- block:
+    - name: Run yum_update.sh
+      command: >
+        buildah run
+          --volume {{ yum_update.path }}:/tmp/yum_update.sh
+          --volume {{ yum_repos_dir_path }}:/etc/yum.repos.d
+          {% for repo in file_repos.stdout_lines %}
+            {% if repo|exists %}
+              --volume {{ repo }}:{{ repo }}
+            {% endif %}
+          {% endfor %}
+          --user root
+          --net host
+          {{ from_image }}
+          /tmp/yum_update.sh "{{ update_repo }}"
+      register: result
+
+  rescue:
+    - name: Run yum_update.sh (retry)
+      command: >
+        buildah --debug run
+          --volume {{ yum_update.path }}:/tmp/yum_update.sh
+          --volume {{ yum_repos_dir_path }}:/etc/yum.repos.d
+          {% for repo in file_repos.stdout_lines %}
+            {% if repo|exists %}
+              --volume {{ repo }}:{{ repo }}
+            {% endif %}
+          {% endfor %}
+          --user root
+          --net host
+          {{ from_image }}
+          bash -x /tmp/yum_update.sh "{{ update_repo }}"
+      retries: 2
+      delay: 3
+      register: result
+      until: result.rc == 0
 
 - name: Remove temporary yum_update.sh script
   file: