Fix 'Regen pem' handler

Currently, 'Regen pem' handler does not ensure that newline is added
between certificates when combining multiple files together.
It may be a problem, especially for hashi_vault pki backend which
doesn't add newline at the end of certificate file.

Change-Id: Ic703e74532874e0912e21244153fb8c31cfebe31
Signed-off-by: Damian Dabrowski <damian.dabrowski@cleura.com>

handlers/main.yml

@@ -14,13 +14,25 @@
 # limitations under the License.
 
 - name: Regen pem # noqa: no-changed-when
-  ansible.builtin.shell: >-
-    cat {{ item_base_path ~ '.crt' }} $(test -f {{ item_base_path  ~ '-ca.crt' }} &&
-    echo {{ item_base_path  ~ '-ca.crt' }}) {{ item_base_path  ~ '.key' }} > {{ target_base_path  ~ '.pem' }}
+  ansible.builtin.shell: |
+      {
+      files=(
+          "{{ item_base_path ~ '.crt' }}"
+          "$(test -f {{ item_base_path  ~ '-ca.crt' }} && echo {{ item_base_path  ~ '-ca.crt' }})"
+          "{{ item_base_path  ~ '.key' }}"
+      )
+      for f in "${files[@]}"; do
+          cat "$f"
+          # adds a newline at the end of file's content if it doesn't exist
+          tail -c1 "$f" | grep -q '^$' || echo
+        done
+      } > {{ target_base_path  ~ '.pem' }}
+  args:
+    executable: /bin/bash
   vars:
     item_interface: "{{ item['interface'] | default('') }}"
     item_name: "{{ ('interface' in item and item['interface'] is truthy) | ternary(item['address'] ~ '-' ~ item_interface, item['address']) }}"
-    item_base_path: "{{ haproxy_ssl_temp_path  ~ '/haproxy_' ~ ansible_facts['hostname'] ~ '-' ~ item_name }}"
+    item_base_path: "{{ haproxy_ssl_temp_path ~ '/haproxy_' ~ ansible_facts['hostname'] ~ '-' ~ item_name }}"
     target_base_path: "{{ haproxy_ssl_cert_path ~ '/haproxy_' ~ ansible_facts['hostname'] ~ '-' ~ item_name }}"
   with_items: "{{ haproxy_vip_binds }}"
   listen: