Allow to apply custom configuration to Nova SSH config

In case compute nodes using non-standard SSH port or some other
hacky connection between each other, deployers might need to
supply extra configuration inside it.

community.general.ssh_config module was not used, as it requires extra
`paramiko` module to be installed on each destination host.

Change-Id: Ic79aa391e729adf61f5653dd3cf72fee1708e2f5

defaults/main.yml

@@ -769,6 +769,12 @@ nova_pki_console_install_certificates:
     mode: "0640"
     condition: "{{ nova_pki_console_condition | bool }}"
 
+# Extra settings which will be applied for `nova` user for offline
+# migrations and resizes. Example:
+# nova_ssh_custom_config:
+#    Port: 2022
+nova_ssh_custom_config: {}
+
 # host which holds the ssh certificate authority
 nova_ssh_keypairs_setup_host: "{{ openstack_ssh_keypairs_setup_host | default('localhost') }}"
 

files/ssh_config

@@ -1,2 +0,0 @@
-Host *
-    StrictHostKeyChecking no

releasenotes/notes/custom_ssh_config-46c443e077b3386b.yaml

@@ -0,0 +1,7 @@
+---
+features:
+  - |
+    Added variable ``nova_ssh_custom_config`` which allows to apply
+    extra configuration for SSH connection established by Nova Compute
+    while perfroming offline migrations or resizes.
+    Can be leveraged to define a custom SSH port or ProxyJump.

tasks/nova_compute.yml

@@ -23,8 +23,8 @@
     - always
 
 - name: Create the nova SSH config file
-  copy:
-    src: "ssh_config"
+  template:
+    src: "ssh_config.j2"
     dest: "{{ nova_system_home_folder }}/.ssh/config"
     owner: "{{ nova_system_user_name }}"
     group: "{{ nova_system_user_name }}"

templates/ssh_config.j2

@@ -0,0 +1,5 @@
+Host *
+    StrictHostKeyChecking no
+{%  for key, value in nova_ssh_custom_config.items()  %}
+    {{ key }} {{ value }}
+{%  endfor  %}