Added option to provision multiple standalone k3s

Fixes #21

README.md

@@ -47,6 +47,7 @@ consistency.
 |----------------------------------|-------------------------------------------------------------------------------------|-----------------------------------------|
 | `k3s_cluster_state`              | State of cluster: installed, started, stopped, restarted, downloaded, uninstalled.  | installed                               |
 | `k3s_release_version`            | Use a specific version of k3s, eg. `v0.2.0`. Specify `false` for latest.            | `false`                                 |
+| `k3s_build_cluster`              | When multiple `play_hosts` are available, attempt to cluster. Read notes below.     | `true`                                 |
 | `k3s_github_url`                 | Set the GitHub URL to install k3s from.                                             | https://github.com/rancher/k3s          |
 | `k3s_install_dir`                | Installation directory for k3s.                                                     | `/usr/local/bin`                        |
 | `k3s_server_manifests_dir`       | Path for place the `k3s_server_manifests_templates`.                                | `/var/lib/rancher/k3s/server/manifests` |
@@ -96,6 +97,22 @@ ensure this is set in your Ansible configuration, eg:
 k3s_release_version: v0.2.0
 ```
 
+#### Important note about `k3s_build_cluster`
+
+If you set `k3s_build_cluster` to `false`, this role will install each play
+host as a standalone node. An example of when you might be building a large
+number of IoT devices running K3s. Below is a hypothetical situation where we
+are to deploy 25 Rasberry Pi devices, each a standalone system and not
+a cluster of 25 nodes. To do this we'd use a playbook similar to the below:
+
+```yaml
+- hosts: k3s_nodes  # eg. 25 RPi's defined in our inventory.
+  vars:
+    k3s_build_cluster: false
+  roles:
+     - xanmanning.k3s
+```
+
 #### Important note about `k3s_non_root`
 
 To install k3s as non root you must not use `become: true`. The intention of

defaults/main.yml

@@ -8,6 +8,11 @@ k3s_cluster_state: installed
 # k3s_release_version: v0.1.0
 k3s_release_version: false
 
+# When multiple play_hosts are present, attempt to cluster the nodes.
+# Using false will create multiple standalone nodes.
+# (default: true)
+k3s_build_cluster: true
+
 # URL for GitHub project
 k3s_github_url: https://github.com/rancher/k3s
 

molecule/default/playbook-standalone.yml

@@ -0,0 +1,9 @@
+---
+- name: Converge
+  hosts: all
+  become: true
+  vars:
+    molecule_is_test: true
+    k3s_build_cluster: false
+  roles:
+    - role: xanmanning.k3s

molecule/highavailability/playbook-dqlite.yml

@@ -5,7 +5,6 @@
   vars:
     molecule_is_test: true
     k3s_dqlite_datastore: true
-    k3s_secrets_encryption: true
     k3s_use_experimental: true
   pre_tasks:
     - name: Set each node to be a control node

tasks/build/preconfigure-k3s.yml

@@ -2,21 +2,22 @@
 
 - name: Ensure k3s control node fact is set
   set_fact:
-    k3s_control_node: false
+    k3s_control_node: "{{ 'false' if k3s_build_cluster else 'true' }}"
   when: k3s_control_node is not defined
 
 - name: Ensure k3s master control node fact is set
   set_fact:
-    k3s_primary_control_node: false
+    k3s_primary_control_node: "{{ 'false' if k3s_build_cluster else 'true' }}"
   when: k3s_primary_control_node is not defined
 
 - name: Ensure a k3s control node is defined if none are found in play_hosts
   block:
-    - name: Set control host
+    - name: Set the control host
       set_fact:
         k3s_control_node: true
       when: inventory_hostname == play_hosts[0]
   when: true not in (hostvars | json_query('*.k3s_control_node'))
+        and k3s_build_cluster is defined and k3s_build_cluster
 
 - name: Ensure a count of control masters is generated
   set_fact:
@@ -29,3 +30,4 @@
     k3s_primary_control_node: true
   when: k3s_controller_count | length > 1
         and inventory_hostname == k3s_controller_count[0]
+        and k3s_build_cluster is defined and k3s_build_cluster

tasks/state-installed.yml

@@ -39,3 +39,4 @@
 
 - import_tasks: build/configure-k3s-cluster.yml
   when: play_hosts | length > 1
+        and k3s_build_cluster is defined and k3s_build_cluster

tasks/validate/main.yml

@@ -5,3 +5,4 @@
 - import_tasks: check-unsupported-rootless.yml
   when: k3s_non_root is defined and k3s_non_root
 - import_tasks: check-master-count.yml
+  when: k3s_build_cluster is defined and k3s_build_cluster