Rudimentary parsing of terraform tfvars in bash

source_tfvars.sh

#!/bin/bash
# source: https://gist.github.com/atward/7a2eb1b4a78fbaebe585
# here be dragons: this is as dangerous as it looks

## terraform variable defaults
# takes *.tf and assigns env=default (if any)
# - map not supported (obvious reasons)
# - Tested on Darwin sed(1) only
function source_tfdefaults() {
    eval "$(
        sed -n '/variable [-a-z0-9_]* {/{:start
            /}/!{N;b start
            }
            s/^variable \([-a-z0-9_]*\).*default *= *"\([^"]*\)".*/\1="\2"/p
        }' "$@"
    )"
}

## tfvars assignments
# takes *.tfvars and assigns env=value
# - works with terraform 0.6 types: string, map
# - map.key becomes map_key
function source_tfvars() {
    eval "$(
        awk 'BEGIN {FS=OFS="="}
        !/^(#| *$)/ && /^.+=.+$/ {
            gsub(/^[ \t]+|[ \t]+$/, "", $1);
            gsub(/\./, "_", $1);
            gsub(/^[ \t]+|[ \t]+$/, "", $2);
            if ($1 && $2) print $0
        }' "$@"
    )"
}

# usage:
#source_tfdefaults *.tf
#source_tfvars "./conf.tfvars"

Did you consider using tfvars.json files and then processing them using jq?