tools: add set-env-variables.sh

Very simple script to set env variables.

schutzbot/mockbuild.sh

@@ -37,8 +37,7 @@ function template_override {
 }
 
 # Get OS and architecture details.
-source /etc/os-release
-ARCH=$(uname -m)
+source tools/set-env-variables.sh
 
 # Register RHEL if we are provided with a registration script and intend to do that.
 REGISTER="${REGISTER:-'false'}"

tools/set-env-variables.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+# don't error on unused ARCH and DISTRO_CODE variables
+# shellcheck disable=SC2034
+
+source /etc/os-release
+ARCH=$(uname -m)
+DISTRO_CODE="${DISTRO_CODE:-${ID}-${VERSION_ID//./}}"