Update ansible readme with important missing details

infrastructure/ansible/README.md

@@ -12,17 +12,19 @@
 
 ## Infrastructure and Servers
 
-Please see the `/inventories/{ENVIRONMENT}/hosts` file for IP details of the designated services. Set these to the server that you created via terraform.
+Please see the `/inventories/{ENVIRONMENT}/hosts` file for IP details of the designated services. Set these to the server's domain name/s that you created via terraform.
 
 ## Ansible
 
 ### SSH Access
 
-To authenticate yourself on the remote servers your ssh key will need to be added to the `sudoers` var in the _/inventories/{ENVIRONMENT}/group_vars/all.yml_.
+To authenticate users and to allow them to have sudo access on the remote servers your ssh key will need to be added to the `sudoers` var in the _/inventories/{ENVIRONMENT}/group_vars/all.yml_.
 
-To have docker access you need to add your ssh key to the  `docker_users` var in the _/inventories/{ENVIRONMENT}/group_vars/all.yml_.
+To authenticate users and to allow them to have docker access you need to add your ssh key to the  `docker_users` var in the _/inventories/{ENVIRONMENT}/group_vars/all.yml_.
 
-An authorised user will need to run the `provision_servers.yml` playbook to add your ssh key to the servers.
+Ensure that you remove all users that you don't want to have access. The default development files have a bunch of Jembi staff's user credentials.
+
+An pre-authorised user will need to run the `provision_servers.yml` playbook the first time to add your ssh key to the servers.
 
 ### Configuration
 
@@ -32,6 +34,8 @@ Before running the ansible script add the server to your known hosts file else a
 ssh-keyscan -H <host> >> ~/.ssh/known_hosts
 ```
 
+Next, ensure that you configure the `firewall_subnet_restriction` property of the _/inventories/{ENVIRONMENT}/group_vars/all.yml_ file if you are setting up multiple nodes in a Docker swarm. Docker swarm nodes need to communicate with each other, this property adds a restriction on the software firewall on each node (UFW) which only allow that communication to happen on the particular subset specified by this property.
+
 To run a playbook you should do:
 
 ```bash