Populate /etc/hosts to allow hosts to refer to each other by name

Author: Matt Pryor

group_vars/cluster.yml

@@ -11,3 +11,6 @@ secrets_openhpc_mungekey: "{{ hostvars[groups['control'][0]].ansible_local.openh
 
 # Override this to cope with the case where the podman group just doesn't exist
 appliances_local_users_podman_enable: "{{ groups.get('podman', []) | length > 0 }}"
+
+# Use the short hostname as the default internal address
+internal_address: "{{ ansible_hostname }}"

slurm-infra.yml

@@ -54,6 +54,19 @@
       loop: "{{ groups.get('cluster', []) }}"
       when: cluster_run_validation | default(false) | bool
 
+# Ensure that the hosts in the cluster can all refer to each other by their inventory hostname
+- hosts: cluster
+  become: yes
+  tasks:
+    - name: Populate /etc/hosts with cluster hosts
+      lineinfile:
+        path: /etc/hosts
+        regexp: "{{ hostvars[host].ansible_hostname }}"
+        line: "{{ hostvars[host].ansible_default_ipv4.address }} {{ hostvars[host].ansible_fqdn }} {{ hostvars[host].ansible_hostname }}"
+      loop: "{{ ansible_play_hosts }}"
+      loop_control:
+        loop_var: host
+
 # Ensure that the secrets are generated and persisted on the control host
 - name: Generate and persist secrets
   hosts: control