yum_update.sh improvements

* Use <yum|dnf> repoquery instead of repoquery directly

  "repoquery" is part of <yum|dnf>-utils which may not be installed, in
  which case no packages would end up updated.

* Use the --quiet flag with repoquery

  This prevents notices such as subscription-related stderr warnings
  from being added to the output and messing with the sorted order.

* Remove the : after else

  It seems using else without a colon is the bash standard. This gets
  rid of the following error on RHEL8:
  "/tmp/yum_update.sh: line 34: else:: command not found"

Depends-On: https://review.opendev.org/662317
Change-Id: Id03405d49dc213d018941c44129521cca845e7d6

files/yum_update.sh

@@ -2,10 +2,12 @@
 
 set -eou pipefail
 
+PKG="$(command -v dnf || command -v yum)"
+
 packages_for_update=
-if [ -n "$1" ] && command -v repoquery >/dev/null 2>&1; then
+if [ -n "$1" ] && $PKG repoquery >/dev/null 2>&1; then
     installed_versions=$(rpm -qa --qf "%{NAME} = %{VERSION}-%{RELEASE}\n" | sort)
-    available_versions=$(repoquery --provides --disablerepo='*' --enablerepo=$1 -a | sort)
+    available_versions=$($PKG repoquery --quiet --provides --disablerepo='*' --enablerepo=$1 -a | sort)
     uptodate_versions=$(comm -12 <(printf "%s\n" "$installed_versions") <(printf "%s\n" "$available_versions"))
 
 
@@ -22,14 +24,13 @@ if [ -z "$packages_for_update" ]; then
     exit
 fi
 
-PKG="$(command -v dnf || command -v yum)"
 PKG_MGR="$(echo ${PKG:(-3)})"
 
 if [ $PKG_MGR == "dnf" ]; then
     if ! echo $installed | grep -qw dnf-plugins-core; then
         $PKG install -y dnf-plugins-core
     fi
-else:
+else
     if ! echo $installed | grep -qw yum-plugin-priorities; then
         $PKG install -y yum-plugin-priorities
     fi