terraform state file to ansible inventory, grouped by first tag value.

tf2inventory.sh

JQ='.modules[0].resources 
    | map(select(.primary.attributes."tags.0") 
    | { tag: .primary.attributes."tags.0", ip: .primary.attributes.ipv4_address, name:  .primary.attributes.name })  
    | group_by(.tag) 
    | map (["["+.[0].tag+"]", (map([.name, "ansible_ssh_host=" + .ip] | join(" ")) | join("\n"))]|join("\n") ) 
    | join("\n\n")'
jq -r "$JQ" $1

Groups terraform resources by tag value into the ansible inventory format.

$ ./tf2ansible.sh terraform.tfstate
[api]
thing-api-nyc3-bb ansible_ssh_host=159.65.162.3

[db]
thing-sql-nyc3-zz ansible_ssh_host=99.227.102.3
thing-sql-nyc3-bb ansible_ssh_host=165.227.102.2