clhm.ignition-warnings: Improve test to ignore additional warnings

Signed-off-by: Jan Schintag <jan.schintag@de.ibm.com>

tests/kola/clhm/ignition-warnings/test.sh

@@ -1,31 +1,28 @@
 #!/bin/bash
 # kola: { "platforms": "qemu-unpriv", "allowConfigWarnings": true }
-# - platforms: qemu-unpriv 
-#   - This test should pass everywhere if it passes anywhere. 
-# - allowConfigWarnings: true 
-#   - We intentionally exclude the Install section from a systemd unit.  
-#     This is valid but not ideal, so Butane warns about it.  
+# - platforms: qemu-unpriv
+#   - This test should pass everywhere if it passes anywhere.
+# - allowConfigWarnings: true
+#   - We intentionally exclude the Install section from a systemd unit.
+#     This is valid but not ideal, so Butane warns about it.
 # This test ensures that Ignition warnings are displayed on the console.
 
 set -xeuo pipefail
 
 . $KOLA_EXT_DATA/commonlib.sh
 
-WARN='\033[0;33m' # yellow
-RESET='\033[0m' # reset
+WARN='\e\[0;33m' # yellow
+RESET='\e\[0m' # reset
 
+warning="${WARN}Ignition: warning at \\$.systemd.units.0.contents: unit \"echo.service\" is enabled, but has no install section so enable does nothing${RESET}"
 warningsfile="/etc/issue.d/30_coreos_ignition_warnings.issue"
-tmpd=$(mktemp -d)
-expectedwarningsfile="${tmpd}"/expectedwarningsfile
 
 # Check for the motd file
 if ! test -f ${warningsfile}; then
     fatal "not found Ignition warnings issue file"
 fi
 
-echo -e "${WARN}Ignition: warning at $.systemd.units.0.contents: unit \"echo.service\" is enabled, but has no install section so enable does nothing${RESET}" > $expectedwarningsfile
-
-if ! diff $expectedwarningsfile $warningsfile; then
+if ! grep -P -q "${warning}" "${warningsfile}"; then
     fatal "Ignition warning did not show up as expected in issue.d"
 fi
 ok "Successfully displayed Ignition warning on the console"