Pin minor version only if customer has not done so already

Author: hgreebe

cli/src/pcluster/resources/imagebuilder/parallelcluster.yaml

@@ -195,8 +195,11 @@ phases:
 
               if [[ ${!PLATFORM} == RHEL ]]; then
                 if [[ ${!OS} == rhel9 ]] || [[ ${!OS} == rocky9 ]]; then
-                  echo ${!VERSION} > /etc/yum/vars/releasever
-                  yum clean all
+                  if [[ ! -f /etc/yum/vars/releasever ]]; then
+                    echo "yes" > /opt/parallelcluster/pin_releasesever
+                    echo ${!VERSION} > /etc/yum/vars/releasever
+                    yum clean all
+                  fi
                 fi
                 yum -y update krb5-libs
                 yum -y groupinstall development && sudo yum -y install curl wget jq

cli/src/pcluster/resources/imagebuilder/update_and_reboot.yaml

@@ -168,9 +168,12 @@ phases:
               PLATFORM='{{ build.PlatformName.outputs.stdout }}'
               VERSION='{{ build.OperatingSystemVersion.outputs.stdout }}'
               if [[ ${!OS} == rhel9 ]] || [[ ${!OS} == rocky9 ]]; then
+                if [[ ! -f /etc/yum/vars/releasever ]]; then
+                  echo "yes" > /opt/parallelcluster/pin_releasesever
                   echo ${!VERSION} > /etc/yum/vars/releasever
                   yum clean all
                 fi
+              fi
 
               if [[ ${!PLATFORM} == RHEL ]]; then
                 yum -y install jq