Separate Ansible world into setup and deployment.

This makes it possible to run a deployment as opposed to a 'setup' play
where all the necessary prerequisites are arranged on the server. We
don't need to do that each time.

Closes decentral1se/xppl#4.

Might help decentral1se/xppl#2.

ansible/README.md

@@ -1,14 +1,27 @@
 # XPPL Ansible Automation
 
-An automated deployment for the XPPL.
+An automated deployment for the XPPL. If you're running these scripts, you'll
+need SSH access and Sudo permissions on the machines. It is already running
+deployments for:
 
-## Run It
+* [books.vvvvvvaria.org](https://books.vvvvvvaria.org/)
 
-You'll need to have SSH and Sudo access to [varia.zone] first.
+## Prerequisites
+
+You'll need to install [Ansible](https://docs.ansible.com).
 
 ```bash
 $ sudo apt install -y ansible
-$ ansible-playbook --ask-become-pass plays/main.yml
 ```
 
-[varia.zone]: https://varia.zone/
+## Setup a New XPPL
+
+```bash
+$ ansible-playbook --limit varia-zone --ask-become-pass plays/setup.yml
+```
+
+## Deploy a New XPPL Version
+
+```bash
+$ ansible-playbook --limit varia-zone --ask-become-pass plays/deploy.yml
+```

ansible/inventory

@@ -1,2 +1,2 @@
-[varia-zone]
+[managed]
 varia.zone ansible_ssh_port=12345

ansible/plays/deploy.yml

@@ -0,0 +1,20 @@
+---
+
+- hosts: managed
+  pre_tasks:
+    - name: Shutdown the running XPPL for the deployment.
+      become: true
+      supervisorctl:
+        name: 'xppl:'
+        state: stopped
+  roles:
+    - role: git     # Clone the project source
+    - role: pipenv  # Install Python dependencies
+    - role: env     # Configure the application environment
+    - role: nginx   # Setup the Nginx configuration
+  post_tasks:
+    - name: Start back up the XPPL after the deployment.
+      become: true
+      supervisorctl:
+        name: 'xppl:'
+        state: stopped

ansible/plays/setup.yml

@@ -1,11 +1,11 @@
 ---
 
-- hosts: varia-zone
+- hosts: managed
   roles:
     - role: perms       # Setup users and groups
     - role: git         # Clone the project source
     - role: pipenv      # Install Python dependencies
-    - role: env         # Configure application environment
+    - role: env         # Configure the application environment
     - role: rqlite      # Install RQLite
     - role: supervisor  # Setup managed processes
-    - role: nginx       # Setup Nginx configuration
+    - role: nginx       # Setup the Nginx configuration