move compute_init tasks to right place and document

Author: sjpb

ansible/extras.yml

@@ -37,7 +37,7 @@
     - import_role:
         name: persist_hostkeys
 
-# TODO: I'm not convinced this is the right place
+# TODO: Is this is the right place?
 - hosts: compute_init:!builder
   tags: compute_init
   become: yes
@@ -47,17 +47,6 @@
         name: compute_init
         tasks_from: export.yml
 
-# TODO: really this should only run during build
-# but handy not to for debugging without build
-- name: Install compute_init script
-  hosts: compute_init
-  tags: compute_init
-  become: yes
-  tasks:
-    - include_role:
-        name: compute_init
-        tasks_from: install.yml
-
 - name: Install k9s
   become: yes
   hosts: k9s

ansible/fatimage.yml

@@ -55,6 +55,16 @@
 
 - import_playbook: extras.yml
 
+# TODO: is this the right place?
+- name: Install compute_init script
+  hosts: compute_init
+  tags: compute_init # tagged to allow running on cluster instances for dev
+  become: yes
+  tasks:
+    - include_role:
+        name: compute_init
+        tasks_from: install.yml
+
 - hosts: builder
   become: yes
   gather_facts: yes

ansible/roles/compute_init/tasks/main.yml

@@ -1,15 +1,47 @@
+# compute-init
+
+TODO: describe current status.
+
+# Development
 
 To develop/debug this without actually having to build an image:
 
-On deploy host:
 
-    .stackhpc/ (venv) [rocky@steveb-dev slurm-app-rl9]$ ansible-playbook ansible/extras.yml --tags compute_init
+1. Add the compute nodes into the `compute_init` group:
 
-On compute node:
+        cat <<EOF >> $APPLIANCES_ENVIRONMENT_ROOT/inventory/extra_groups
+        [compute_init:children]
+        compute
+        EOF
 
-    [root@rl9-compute-0 rocky]# rm -f /var/lib/ansible-init.done && systemctl restart ansible-init
-    [root@rl9-compute-0 rocky]# systemctl status ansible-init
+2. Deploy a cluster using tofu and ansible/site.yml as normal. This will
+   additionally configure the control node to export compute hosts over NFS.
+   Check the cluster is up.
+
+3. Reimage the compute nodes:
+
+        ansible-playbook --limit compute ansible/adhoc/rebuild
+
+4. Add metadata to a compute node e.g. via Horzon to turn on compute-init
+   playbook functionality.
+
+5. Fake an image build to deploy the compute-init playbook:
+
+        ansible-playbook ansible/fatimage.yml --tags compute_init
+
+6. Fake a reimage of compute to run ansible-init and the compute-init playbook:
+
+    On compute node where metadata was added:
+
+        [root@rl9-compute-0 rocky]# rm -f /var/lib/ansible-init.done && systemctl restart ansible-init
+        [root@rl9-compute-0 rocky]# systemctl status ansible-init
+
+    Use `systemctl status ansible-init` to view stdout/stderr from Ansible.
+
+Steps 5/6 can be repeated with changes to the compute script. If desirable
+reimage the compute node(s) first as in step 3.
 
+# Results/progress
 
 Without any metadata:
 

docs/experimental/compute-init.md

@@ -20,4 +20,4 @@ nfs_configurations:
     nfs_enable:
         server: "{{ inventory_hostname in groups['control'] }}"
         clients: false
-    nfs_export: "/exports/cluster" # control node has to copy in /etc/hosts to here
+    nfs_export: "/exports/cluster"