Add a chapter to the tutorial explaining HTTPS and mTLS configuration

docs/source/tutorial/toc.rst

@@ -9,3 +9,4 @@
    tutorial03
    tutorial04
    tutorial05
+   tutorial06

docs/source/tutorial/tutorial06.rst

@@ -0,0 +1,85 @@
+Securing the server
+===================
+
+**Senior**
+
+  Hi...  I hope you rested last night!
+
+  Come on, I need your help here!
+
+**Junior**
+
+  Good morning! What's the matter? Sounds worrying
+
+**Senior**
+
+  We forgot to take the most basic security measures when deploying our services.
+  Every body at the company can access the services and the information is
+  transferred in clear text.
+
+**Junior**
+
+  Oh! Damn, you're right! You think we can do anything to solve this mess?
+
+**Senior**
+
+  Yes, I'm pretty sure that those smart guys have thought on that when building
+  Kapow! Have a look at the `documentation </examples/https_mtls>`_.
+
+**Junior**
+
+  Got it! They did it, here're the instictions to start a server with HTTPS support.
+
+  It's amazing! It says we can even use mTLS to control access, really promising.
+
+**Senior**
+
+  Ok, ok... First thigs first. We need to get a server certificate to start
+  working with HTTPS. Fortunately we can ask for one to the CA we use for the
+  other servers. Let's pick up one for development, they're quick to get.
+
+**Junior**
+
+  Yeah! I'll change the startup script to configure HTTPS:
+
+  .. code-block:: console
+
+     $ kapow server --keyfile /etc/kapow/tls/keyfile --certfile /etc/kapow/tls/certfile /etc/kapow/awesome.pow
+
+  It's easy, please copy the private key file and certificate chain to `/etc/kapow/tls` and we can restart.
+
+**Senior**
+
+  Great! it's working, communications are secured. Let's say everybody to change
+  from http to https.
+
+**Junior**
+
+  Ok, did it. What are the steps to follow to limit access by using mTLS?
+
+**Senior**
+
+  Besides configuring the server we need to provide the users with their own
+  client certificates and private keys so they can configure their browsers and
+  the application server.
+
+**Junior**
+
+  Yes, please give me the CA certificate that will issue our client certificates
+  and I'll change the startup script again
+
+  .. code-block:: console
+
+     $ kapow server --keyfile /etc/kapow/tls/keyfile --certfile /etc/kapow/tls/certfile --clientauth=true --clientcafile /etc/kapow/tls/clientCAfile /etc/kapow/awesome.pow
+
+  Done!
+
+**Senior**
+
+  Ok, let's communicate the changes to all the affected teams before we restart
+
+**Junior**
+
+  Oh God, After all we're starting to look like Google
+
+  (chuckles)