From a297c0401dc4d8cdfc84734ece4ecaa515242369 Mon Sep 17 00:00:00 2001
From: Jens Timmerman <github@caret.be>
Date: Fri, 11 Sep 2020 00:23:53 +0200
Subject: [PATCH] only add new databases if they are not yet present

fixes #147
---
 tasks/databases.yml | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tasks/databases.yml b/tasks/databases.yml
index e01d804..f998ddd 100644
--- a/tasks/databases.yml
+++ b/tasks/databases.yml
@@ -1,4 +1,16 @@
 ---
+- name: Collect PostgreSQL db_names
+  postgresql_query:
+    login_host: "{{ item.login_host | default('localhost') }}"
+    login_password: "{{ item.login_password | default(omit) }}"
+    login_user: "{{ item.login_user | default(postgresql_user) }}"
+    login_unix_socket: "{{ item.login_unix_socket | default(postgresql_unix_socket_directories[0]) }}"
+    port: "{{ item.port | default(omit) }}"
+    query: "SELECT datname FROM pg_database;"
+  register: postgresql_present_db_names
+  become: true
+  become_user: "{{ postgresql_user }}"
+  
 - name: Ensure PostgreSQL databases are present.
   postgresql_db:
     name: "{{ item.name }}"
@@ -19,3 +31,5 @@
   # See: https://github.com/ansible/ansible/issues/16048#issuecomment-229012509
   vars:
     ansible_ssh_pipelining: true
+  when: "item.name not in (postgresql_present_db_names.query_result | map(attribute='datname') )"
+