Comment by zaneb for With below Heat statements under runcmd: - str_replace: template: dns-statroute-eth0.sh %eth0_gateway% %oam_stat_routes% parameters: "%eth0_gateway%": { get_param: dns_oam_gateway } "%oam_stat_routes%": { get_param: oam_stat_routes } The VM was launched but the intended command failed to be executed. Here is the related content in /var/lib/cloud/instances/58acd270-3622-48cf-96ef-9ff73d579693/user-data.txt file. Seems the parameter replacement didn't happen. #cloud-config runcmd: - parameters: {'%eth0_gateway%': 192.168.183.97, '%oam_stat_routes%': 192.168.0.0/16 192.168.127.0/24 } str_replace: null template: dns-statroute-eth0.sh %eth0_gateway% %oam_stat_routes%