Alternative approach using sed and some for loop variables

[jessuppi]

Hello @ergin and thank you very much for your work on this script, I came across it a few times and finally implemented your research into my SlickStack script after several users asked for it.

This is not so much a feature request, but in case you wanted to share an alternative way to build cloudflare.conf using sed and an existing boilerplate, it seems to work okay...

Ref: https://github.com/littlebizzy/slickstack/blob/master/bash/ss-install-nginx-cloudflare-ips.txt

## ipv4 list ##
CLOUDFLARE_IPV4_LIST=$(for i in `curl -s -L https://www.cloudflare.com/ips-v4`; do
    echo "set_real_ip_from $i;" >> /tmp/ips-v4.txt;
done)

sed -i -e '/@CLOUDFLARE_IPV4_LIST/{r /tmp/ips-v4.txt' -e 'd' -e '}' "${TMP_CLOUDFLARE_CONF}"

## ipv6 list ##
CLOUDFLARE_IPV6_LIST=$(for i in `curl -s -L https://www.cloudflare.com/ips-v6`; do
    echo "set_real_ip_from $i;" >> /tmp/ips-v6.txt;
done)

sed -i -e '/@CLOUDFLARE_IPV6_LIST/{r /tmp/ips-v6.txt' -e 'd' -e '}' "${TMP_CLOUDFLARE_CONF}"

This is an example boilerplate:

https://github.com/littlebizzy/slickstack/blob/master/modules/nginx/includes/cloudflare-conf.txt

And the placeholders in the boilerplate @CLOUDFLARE_IPV4_LIST and @CLOUDFLARE_IPV6_LIST get replaced via sed using your nifty bash for loop and a few tmp files.

Anyway I had never used sed this way before so just wanted to share. Thanks!

P.S. we credited you in the script comments at the bottom