Merge ~npochet/charm-sysconfig:fix-unnecessary-grub into charm-sysconfig:master

[Nicolas Pochet]

Verify grub parameters and affinity

* Verify that grub parameters are set before running update_grub_file
function. If it is not verified, this function will run and set the
default options through the grub template which is undesirable.
* Verify that systemd parameters are set before running
update_systemd_system_file function.

Verify grub parameters and affinity

* Verify that grub parameters are set before running update_grub_file
function. If it is not verified, this function will run and set the
default options through the grub template which is undesirable.
* Verify that systemd parameters are set before running
update_systemd_system_file function.

[🤖 Canonical IS Merge Bot (canonical-is-mergebot)]

This merge proposal is being monitored by mergebot. Change the status to Approved to merge.

[Drew Freiberger (afreiberger)]

I'm going to pick this up. I'd really like to see this functionality moved to the library and added unittests to ensure that the logic is being processed correctly. As I review the code for syshelper.charm_config, I see that is deprecated and shouldn't be the only source for determining the running of grub, as there are now also grub_config_flags to check.

review: Needs Fixing

[Drew Freiberger (afreiberger)]

Change superceeded by: https://code.launchpad.net/~afreiberger/charm-sysconfig/+git/charm-sysconfig/+merge/377584

review: Disapprove

Unmerged commits

b844615... by Nicolas Pochet on 2020-01-10

Verify grub parameters and affinity

* Verify that grub parameters are set before running update_grub_file
function. If it is not verified, this function will run and set the
default options through the grub template which is undesirable.
* Verify that systemd parameters are set before running
update_systemd_system_file function.

diff --git a/src/reactive/sysconfig.py b/src/reactive/sysconfig.py
index eba0916..ebfb55c 100644
--- a/src/reactive/sysconfig.py
+++ b/src/reactive/sysconfig.py
@@ -52,8 +52,27 @@ def install_sysconfig():
 
     syshelper.install_configured_kernel()
     syshelper.update_cpufreq()
-    syshelper.update_grub_file()
-    syshelper.update_systemd_system_file()
+    if any(syshelper.charm_config[flag] for flag in (
+            'reservation',
+            'hugepages',
+            'hugepagesz',
+            'raid-autodetection',
+            'enable-pti',
+            'enable-iommu',
+            'grub-config-flags',
+            'kernel-version',
+            'update-grub',
+            'config-flags',
+            'cpu-range',
+    )) and syshelper.reservation not in ('off', 'affinity'):
+        syshelper.update_grub_file()
+    if any(syshelper.charm_config[flag] for flag in (
+            'reservation',
+            'systemd-config-flags',
+            'cpu-range',
+            'config-flags',
+    )) and syshelper.reservation not in ('off', 'isolcpus'):
+        syshelper.update_systemd_system_file()
     set_flag('sysconfig.installed')
     update_status()