replace_node.yml: Add a 'dead_nodes_to_ignore' variable

Scylla has an 'ignore_dead_nodes_for_replace' config which allows the user
to ignore dead nodes during the replace and so far it was not supported
by this playbook.
This patch adds support to this feature by adding a variable 'dead_nodes_to_ignore'.
This variable should contain a list with the broadcast addresses of the nodes
that should be ignored during the replace.

example-playbooks/replace_node/replace_node.yml

@@ -188,6 +188,32 @@
       delegate_to: "{{ temporary_seed }}"
       run_once: true
 
+    - name: Set ignore_dead_nodes_for_replace using host ids
+      block:
+        - name: Set dead nodes host ids
+          set_fact:
+            _dead_nodes_host_ids: "{{ _dead_nodes_host_ids | default([]) + [item.value] }}"
+          when: item.key in dead_nodes_to_ignore
+          loop: "{{ _host_ids.json }}"
+
+        - name: Set ignore_dead_nodes_for_replace in scylla.yaml
+          lineinfile:
+            path: /etc/scylla/scylla.yaml
+            regexp: '^(#\s*)?ignore_dead_nodes_for_replace:'
+            line: "ignore_dead_nodes_for_replace: {{ _dead_nodes_host_ids | join(',')}}"
+            create: yes
+      when: dead_nodes_to_ignore|length > 0 and _replace_node_first_boot_grep.failed == false
+
+    # If the _replace_node_first_boot_grep failed, it means that in this scylla version we are still using
+    # addresses instead of host ids for replace, so let's set broadcast addresses in ignore_dead_nodes_for_replace
+    - name: Set ignore_dead_nodes_for_replace using addresses
+      lineinfile:
+        path: /etc/scylla/scylla.yaml
+        regexp: '^(#\s*)?ignore_dead_nodes_for_replace:'
+        line: "ignore_dead_nodes_for_replace: {{ dead_nodes_to_ignore | join(',')}}"
+        create: yes
+      when: dead_nodes_to_ignore|length > 0 and _replace_node_first_boot_grep.failed
+
     - name: Set replace_node_first_boot
       block:
         - set_fact:
@@ -265,6 +291,13 @@
         state: absent
       when: _replace_node_first_boot_grep.failed
 
+    - name: Remove the ignore_dead_nodes_for_replace record
+      lineinfile:
+        path: /etc/scylla/scylla.yaml
+        regexp: '^ignore_dead_nodes_for_replace:'
+        state: absent
+      when: dead_nodes_to_ignore|length > 0
+
     - name: Restore seeds list
       lineinfile:
         path: /etc/scylla/scylla.yaml

example-playbooks/replace_node/vars/main.yml

@@ -51,3 +51,7 @@ alive_nodes_listen_address: "{{ vars['ansible_'~scylla_nic].ipv4.address }}"
 alive_nodes_broadcast_address: "{{ vars['ansible_'~scylla_nic].ipv4.address }}"
 
 cql_port: 9042
+
+# A list with the broadcast addresses of the nodes that are dead and should be ignored during the replace
+# These nodes shouldn't be part of the inventory
+dead_nodes_to_ignore: []