More info for the KinD boilerplate

Signed-off-by: Marco Emilio "sphakka" Poleggi <marcoep@ieee.org>

README.md

@@ -345,17 +345,17 @@ using plain `http`): `http://<VM-DNS-name-or-IP-address>`. You should see the
 homepage showing "nginx, configured by Ansible".
 
 
-### Task #5: Test Desired State Configuration principles ###
+### Task #5: Test the desired state principle ###
 
-**Goal:** test and verify that Ansible implements the principles of Desired
-State Configuration.
+**Goal:** test and verify that Ansible implements the principles of desired
+state and idempotence.
 
-According to this principle, before doing anything, Ansible should establish
-the current state of the managed server, compare it to the desired state
-expressed in the playbook, and then only perform the actions necessary to
-bring the current state to the desired state. In other words, if the managed
-system is already in its desired state, nothing will be done (apart from some
-notable exception -- see below): that's called "idempotence".
+According to the *desired state* principle, before doing anything, Ansible
+should establish the current state of the managed server, compare it to the
+goals expressed in the playbook, and then only perform the actions necessary
+to bring the current state to the desired state. In other words, if the
+managed system is already in its desired state, nothing will be done (apart
+from some notable exception -- see below): that's called "[idempotence](https://en.wikipedia.org/wiki/Idempotence)".
 
 In its ouput, Ansible marks tasks where it had to perform some action as
 *changed* whereas tasks where the actual state already corresponded to the
@@ -387,7 +387,6 @@ desired state as *ok*.
 on.
 
 
-
 ### Task #6: Adding a handler for nginx restart ###
 
 **Goal:** improve the playbook by restarting nginx only when needed.

ansible/playbooks/kind-metallb.yml

@@ -31,9 +31,16 @@
     #   "metallb-native.yml"), using a block here is recommended!
     # - Configuration tasks shall trigger their respective deployments.
 
+    # Optional *bonus* auxiliary task for the "rebuild all"
+    # Checks the existence of a KinD cluster
+    # - Capture output with "register" and use it as condition with
+    #   "changed_when"
+    # - Should trigger the creation of the KinD cluster if no cluster is running (even
+    #   if its config hasn't changed)
 
     # Optional *bonus* on-demand tasks:
 
+    # [** Mandatory for the groups of 3 **]
     # - Rebuild all: manually reprovision the cluster and redeploy the
     #   application (tip: notify via a signal). This might require an extra
     #   task that checks the existence of a KinD cluster.