myip

#!/bin/sh

# myip: get "external" (wan) ip address

dig="dig +short"
curl="curl --silent --fail --location --max-time 5"

# shuffle commands to not always "ping" the same server, but prefer dns queries
# (which are faster) over http apis
cmds="$(shuf << EOF
$dig @ns1-1.akamaitech.net ANY whoami.akamai.net
$dig @ns1.google.com TXT o-o.myaddr.l.google.com
$dig @resolver1.opendns.com myip.opendns.com
$dig @resolver2.opendns.com myip.opendns.com
$dig @resolver3.opendns.com myip.opendns.com
$dig @resolver4.opendns.com myip.opendns.com
EOF
)"

cmds="$cmds
$(shuf << EOF
$curl https://api.ipify.org
$curl https://checkip.amazonaws.com
$curl https://ident.me
$curl https://ifconfig.me/ip
$curl https://ipecho.net/plain
$curl https://ipinfo.io/ip
$curl https://myip.dnsomatic.com
EOF
)"

# set IFS to \n to iterate over lines
IFS='
'

for cmd in $cmds; do
        ip="$(eval "$cmd")"
        if [ "$?" -ne 0 ]; then
                continue
        fi

        # the ip string returned by some service may be quoted, so tr removes
        # (also) " chars
        ip="$(printf '%s' "$ip" | tr -d '"[:space:]')"
        if [ -z "$ip" ]; then
                continue
        fi

        printf '%s\n' "$ip"
        exit 0
done

echo "error: unable to get wan ip" >&2
exit 1