test: Fix COMPOSE_URL issue and add set-env-variables.sh

test/cases/ostree-rebase.sh

@@ -1,13 +1,17 @@
 #!/bin/bash
 set -euo pipefail
 
+# Get OS data.
+source /usr/libexec/osbuild-composer-test/set-env-variables.sh
+
+# Get compose url if it's running on unsubscried RHEL
+if [[ ${ID} == "rhel" ]] && ! sudo subscription-manager status; then
+    source /usr/libexec/osbuild-composer-test/define-compose-url.sh
+fi
+
 # Provision the software under test.
 /usr/libexec/osbuild-composer-test/provision.sh
 
-# Get OS data.
-source /etc/os-release
-ARCH=$(uname -m)
-
 # Colorful output.
 function greenprint {
     echo -e "\033[1;32m[$(date -Isecond)] ${1}\033[0m"