fix: postgresql_cert_name didn't work properly, using this parameter

caused an error. Because there was a missing variable __pg_server_crt
definition in the correct context. This commit also enhances the description
of postgresql_cern_name variable.

Related: SYSROLES-157

README.md

@@ -92,7 +92,9 @@ postgresql_ssl_enable: true
 If you want to use your own certificate and private key, use the
 `postgresql_cert_name` variable to specify the certificate name. You must keep
 both certificate and key files in the same directory and under the same name
-with the `.crt` and `.key` suffixes.
+with the `.crt` and `.key` suffixes on the managed node. The value should be an
+absolute path.
+
 
 For example, if your certificate file is located in `/etc/certs/server.crt` and
 your private key in `/etc/certs/server.key`, set the `postgresql_cert_name`

tasks/certificate.yml

@@ -52,6 +52,9 @@
     - __postgresql_cert.stat.exists
     - __postgresql_key.stat.exists
     - postgresql_certificates | length < 1
+  vars:
+    __pg_server_crt: "{{ __postgresql_data_dir }}/server.crt"
+    __pg_server_key: "{{ __postgresql_data_dir }}/server.key"
   block:
     - name: Install certificate file
       file: