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

spruce.json

{"flavor":"1.29.0","prune":["meta"],"env":["HOME=/home/user"],"cherry_pick":[],"yaml":[{"filename":"original_bosh.yml","contents":"--- # original_bosh.yml\naddons:\n- jobs:\n  - name: bosh-dns-aliases\n    properties:\n      aliases:\n      - domain: _.cell.service.cf.internal\n        targets:\n        - deployment: ((deployment_name))\n          domain: bosh\n          instance_group: diego-cell\n          network: ((cf_runtime_network))\n          query: _\n        - deployment: ((deployment_name))\n          domain: bosh\n          instance_group: windows2012R2-cell\n          network: ((cf_runtime_network))\n          query: _\n        - deployment: ((deployment_name))\n          domain: bosh\n          instance_group: windows2016-cell\n          network: ((cf_runtime_network))\n          query: _\n        - deployment: ((deployment_name))\n          domain: bosh\n          instance_group: isolated-diego-cell\n          network: ((cf_runtime_network))\n          query: _\n\n"},{"filename":"group_params.yml","contents":"--- # group_params.yml\niso_group:\n  name: iso-group\n  azs:\n  - z1\n  instances: 1\n  vm_type: small-highmem\n  vm_extensions:\n  - 100GB_ephemeral_disk\n  network_name: ((cf_runtime_network))\n  stemcell: test\n"},{"filename":"final_replace.yml","contents":"--- # final_replace.yml\ntype: replace\npath: /instance_groups/-\nvalue:\n  name: (( grab iso_group.name ))\n  azs: (( grab iso_group.azs ))\n  instances: (( grab iso_group.instances || 1 ))\n  vm_type: (( grab iso_group.vm_type || minimal ))\n  vm_extensions: (( grab iso_group.vm_extensions))\n  stemcell: (( grab iso_group.stemcell || default ))\n  networks:\n  - name: (( grab iso_group.network_name || default ))\n  jobs:\n  - name: rep\n    release: diego\n    properties:\n      bpm:\n        enabled: true\n      diego:\n        executor:\n          instance_identity_ca_cert: ((diego_instance_identity_ca.certificate))\n          instance_identity_key: ((diego_instance_identity_ca.private_key))\n        rep:\n          preloaded_rootfses:\n          - cflinuxfs3:/var/vcap/packages/cflinuxfs3/rootfs.tar\n          placement_tags:\n          - (( grab iso_group.name ))\n"},{"filename":"final_bosh.yml","contents":"--- # final_bosh.yml\naddons:\n- jobs:\n  - name: bosh-dns-aliases\n    properties:\n      aliases:\n      - domain: _.cell.service.cf.internal\n        targets:\n        - ((prepend))\n        - deployment: ((deployment_name))\n          domain: bosh\n          instance_group: (( grab iso_group.name ))\n          network: (( grab iso_group.network_name || default))\n          query: _\n\n"}],"skip_eval":false,"fallback_append":false,"go_patch":false,"debug":false,"trace":false}