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

spruce.json

{"flavor":"1.28.0","prune":["meta"],"env":["HOME=/home/user"],"cherry_pick":[],"yaml":[{"filename":"file1.yml","contents":"meta:\n  job_definition:\n    instances: 1\n    update:\n      serial: false\n      max_in_flight: 4\n    azs: [z1, z2, z3]\n    jobs:\n    - { name: consul_agent, release: consul }\n    network:\n    - name: prod\n    \ninstance_groups:\n- name: haproxy\n  .: (( inject meta.job_definition ))\n  jobs:\n  - { name: haproxy, release: haproxy }\n  update:\n    serial: true\n- name: web\n  .: (( inject meta.job_definition ))\n  jobs:\n  - { name: atc, release: concourse }\n  .: (( inject meta.job_defnition ))\n  - ahha\n\n\n\n"}],"skip_eval":false,"fallback_append":false,"go_patch":false,"debug":false,"trace":false}