jq2sh

#!/usr/bin/env bash
# jq2sh -- Transform input JSON with jq queries into shell assignments
# > jq2sh DEEPDIVE_COMPUTER='.deepdive.computer' DEEPDIVE_COMPUTER_CONFIG='.deepdive.computers[.deepdive.computer]'
# Produces the following output:
#   DEEPDIVE_COMPUTER=${DEEPDIVE_COMPUTER:-local}
#   DEEPDIVE_COMPUTER_CONFIG=${DEEPDIVE_COMPUTER_CONFIG:-'{"type":"local"}'}
# For an input JSON:
#   {"deepdive":{"computer":"local", "computers":{"local":{"type":"local"}, ...}, ...}}
##
set -eu

# assemble a jq program
jqProgram=
for nameEqValueQuery; do
    name=${nameEqValueQuery%%=*}
    valueQuery=${nameEqValueQuery#$name=}
    jqProgram+=",\"$name=\${$name:-\\($valueQuery | (. // \"\" | tostring) | @sh)}\""
done

# run jq to transform input JSON into a shell script
exec jq -c -r "${jqProgram#,}"