If the services can't be modified to load their config directly from env vars, write the config to an off-root scratch volume (e.g. mounted to /tmp/) and have t

If the services can't be modified to load their config directly from env vars, write the config to an off-root scratch volume (e.g. mounted to /tmp/) and have them load from that. The root volume should be mounted read-only either way to prevent modification of your services should something get RCE.