a bit o' spruce, from http://play.spruce.cf

spruce.json

{"flavor":"1.17.0","prune":["meta"],"env":["HOME=/home/user"],"cherry_pick":[],"yaml":[{"filename":"mjolnir.yml","contents":"--- # mjolnir.yml\n\nenvironment:\n  https: \"http://\"\n  logmet_elkadapter_secret: secret\n  logmet_elkadapter_tenant_id: marc\n  logmet_elkadapter_hostname: schunk.com\n  protocol: (( grab environment.https || \"\" ))\n  url: (( concat  environment.protocol environment.logmet_elkadapter_tenant_id \":\" environment.logmet_elkadapter_secret \"@\" environment.logmet_elkadapter_hostname  || environment.logmet_elkadapter_hostname || nil ))\n\nurl_final: (( grab environment.url ))\n\n"}],"skip_eval":false,"fallback_append":false,"go_patch":false,"debug":false,"trace":false}