From 5ff5e6b10011875d1c29d16a8b39498adc0145e0 Mon Sep 17 00:00:00 2001
From: Mark Goddard <mark@stackhpc.com>
Date: Tue, 4 Aug 2020 17:17:38 +0100
Subject: [PATCH] Performance: skip LVM configuration if no groups configured

Currently we import the manage-lvm role with a condition that skips
tasks when no LVM groups are configured. At large scale this is
inefficient.

This change improves the performance for hosts where there are no LVM
groups configured, by using include_role rather than a static import.

Story: 2007993
Task: 40664

Change-Id: Ib51ac445cc787d7045d72a9ecec14434d432d9e7
---
 ansible/lvm.yml | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/ansible/lvm.yml b/ansible/lvm.yml
index 93d6102c6..5ca9f8a9c 100644
--- a/ansible/lvm.yml
+++ b/ansible/lvm.yml
@@ -4,7 +4,7 @@
   tags:
     - lvm
     - upgrade-check
-  pre_tasks:
+  tasks:
     - name: Fail if the LVM physical disks have not been configured
       fail:
         msg: >
@@ -13,6 +13,7 @@
           has a valid 'disks' list.
       with_items: "{{ lvm_groups | default([]) }}"
       when: not item.disks | default([]) or 'changeme' in item.disks | default([])
+
     - name: Fail if the LVM physical disks are configured as a comma-separated string
       fail:
         msg: >
@@ -21,10 +22,14 @@
           each volume group in 'lvm_groups' has a valid 'disks' list.
       with_items: "{{ lvm_groups | default([]) }}"
       when: item.disks | string() == item.disks
-  roles:
-    - role: mrlesmithjr.manage-lvm
-      manage_lvm: True
-      become: True
+
+    - name: Ensure LVM configuration is applied
+      vars:
+        manage_lvm: True
+      include_role:
+        name: mrlesmithjr.manage-lvm
+        apply:
+          become: True
       when:
         - lvm_groups is defined
         - lvm_groups | length > 0