OpenWRT pbr for aws by regions

pbr.user.aws

#!/bin/sh
# shellcheck disable=SC2015,SC3003,SC3060
TARGET_URL='https://ip-ranges.amazonaws.com/ip-ranges.json'
TARGET_DL_FILE='/var/pbr_tmp_aws_ip_ranges.gz'
TARGET_TABLE='inet fw4'
TARGET_INTERFACE='wan'
TARGET_REGIONS='ap-southeast-3 ap-southeast-5 ap-southeast-1 GLOBAL'

trap 'rm -f "$TARGET_DL_FILE"' EXIT
_ret=1

mkdir -p "${TARGET_DL_FILE%/*}"

[ -s "$TARGET_DL_FILE" ] || \
        uclient-fetch --no-check-certificate -qO- "$TARGET_URL" | \
                gzip > "$TARGET_DL_FILE"

[ -s "$TARGET_DL_FILE" ] || return 1

json_data="$(zcat "$TARGET_DL_FILE")"

[ "$(uci get pbr.config.ipv6_enabled)" = "1" ] && vers="4 6" || vers="4"
for ver in $vers; do
        case "$ver" in
                4)
                        prefix_path='@.prefixes'
                        region_key='region'
                        ip_key='ip_prefix'
                        ;;
                6)
                        prefix_path='@.ipv6_prefixes'
                        region_key='region'
                        ip_key='ipv6_prefix'
                        ;;
        esac

        params=""
        for region in $TARGET_REGIONS; do
                region_params="$(printf '%s' "$json_data" | jsonfilter -e "$prefix_path[@.$region_key='$region'].$ip_key")"
                [ -n "$region_params" ] && params="${params}${region_params}"$'\n'
        done

        # Trim trailing newline if needed
        params="$(printf "%s" "$params")"

        [ -n "$params" ] && _ret=0 || continue
        nftset="pbr_${TARGET_INTERFACE}_${ver}_dst_ip_user"
        nft "add element $TARGET_TABLE $nftset { ${params//$'\n'/, } }" || _ret=1
done

unset json_data
return $_ret

Removed the tmp file once script exit.
Put json into variable so we don't have to keep decompressing it every time.