add role "swap" - configure swap space (if not already exists)

add_pgnode.yml

@@ -79,6 +79,7 @@
     - role: add-repository
     - role: packages
     - role: sudo
+    - role: swap
     - role: sysctl
     - role: transparent_huge_pages
     - role: pam_limits

deploy_pgcluster.yml

@@ -97,6 +97,7 @@
     - role: add-repository
     - role: packages
     - role: sudo
+    - role: swap
     - role: sysctl
     - role: transparent_huge_pages
     - role: pam_limits

molecule/default/converge.yml

@@ -7,6 +7,7 @@
     - name: Set variables for molecule
       set_fact:
         firewall_enable_ipv6: false  # Added to prevent test failures in CI.
+        swap_file_create: false  # Added to prevent test failures in CI.
         sysctl_set: false  # Added to prevent test failures in CI.
         nameservers: ["8.8.8.8", "9.9.9.9"]
         with_haproxy_load_balancing: true

molecule/postgrespro/converge.yml

@@ -7,6 +7,7 @@
     - name: Set variables for molecule
       set_fact:
         firewall_enable_ipv6: false  # Added to prevent test failures in CI.
+        swap_file_create: false  # Added to prevent test failures in CI.
         sysctl_set: false  # Added to prevent test failures in CI.
         nameservers: ["8.8.8.8", "9.9.9.9"]
         with_haproxy_load_balancing: true

roles/swap/tasks/main.yml

@@ -0,0 +1,68 @@
+---
+# yamllint disable rule:line-length
+
+- name: Ensure swap exists
+  command: swapon --show=SIZE --bytes --noheadings
+  register: swap_exists
+  changed_when: false
+  when: swap_file_create|bool
+  tags: swap, swap_create, swap_remove
+
+- name: Swap exists
+  debug:
+    msg: "swap_size_mb: {{ (swap_exists.stdout_lines|map('trim')|map('int')|sum / 1024 / 1024)|round|int }}"
+  when: swap_exists.stdout is defined and swap_exists.stdout | length > 1
+  tags: swap, swap_create, swap_remove
+
+# if the swap exists and the size is not equal to swap_file_size_mb
+- block:
+    - name: Disable all existing swaps
+      command: swapoff --all
+
+    - name: Remove swap from /etc/fstab
+      lineinfile:
+        path: /etc/fstab
+        state: absent
+        regexp: ' swap '
+
+    - name: Remove swap file (if exists)
+      file:
+        path: "{{ swap_file_path }}"
+        state: absent
+  when: (swap_exists.stdout is defined and swap_exists.stdout | length > 1) and
+        ((swap_exists.stdout_lines|map('trim')|map('int')|sum / 1024 / 1024)|round|int != swap_file_size_mb|int)
+  tags: swap, swap_remove
+
+# if the swap does not exist
+- block:
+    - name: Create swap file
+      command: >
+        dd if=/dev/zero of={{ swap_file_path }} bs=1M count={{ swap_file_size_mb }}
+        creates='{{ swap_file_path }}'
+
+    - name: Set permissions on swap file
+      file:
+        path: "{{ swap_file_path }}"
+        owner: root
+        group: root
+        mode: 0600
+
+    - name: Make swap file if necessary
+      command: mkswap {{ swap_file_path }}
+      register: mkswap_result
+
+    - name: Run swapon on the swap file
+      command: swapon {{ swap_file_path }}
+
+    - name: Manage swap file entry in fstab
+      mount:
+        name: none
+        src: "{{ swap_file_path }}"
+        fstype: swap
+        opts: sw
+        state: present
+  when: (swap_exists.stdout is defined and swap_exists.stdout | length < 1) or
+        (swap_exists.stdout_lines is defined and (swap_exists.stdout_lines|map('trim')|map('int')|sum / 1024 / 1024)|round|int != swap_file_size_mb|int)
+  tags: swap, swap_create
+
+...

tags.md

@@ -13,6 +13,9 @@
 - hostname
 - dns, nameservers
 - etc_hosts
+- swap
+- - swap_create
+- - swap_remove
 - sysctl, kernel
 - disable_thp
 - limits

vars/system.yml

@@ -30,6 +30,10 @@ locale_gen:
 # Set system locale (LANG,LC_ALL)
 locale: "en_US.utf-8"
 
+# Configure swap space (if not already exists)
+swap_file_create: true  # or 'false'
+swap_file_path: /swapfile
+swap_file_size_mb: '2048'  # change this value for your system
 
 # Kernel parameters
 sysctl_set: true  # or 'false'