Force a update-cache after adding an apt gpg key.

mongodb-org-3.2/tasks/mongodb.yml

@@ -20,9 +20,14 @@
     - name: Install the mongodb apt key
       apt_key: keyserver="hkp://keyserver.ubuntu.com:80" id={{ mongodb_repo_key }} state=present
       when: mongodb_install_from_external_repo
+      register: apt_key_update_cache
+
+    - name: Update the apt cache after adding a new key
+      apt: update_cache=yes
+      when: apt_key_update_cache is changed
 
     - name: Remove the old mongo apt repositories
-      apt_repository: repo="{{ item }}" state=absent
+      apt_repository: repo="{{ item }}" state=absent update_cache=yes
       with_items: '{{ mongodb_old_repositories }}'
       when: mongodb_upgrade_from_older_version