lookatme

Single file curl based shell script reporting external IPv6 and IPv4 address in parallel to be as fast as possible.

Usage

$ lookatme --help
Look at me and tell me my IPv6 and IPv4 address.

lookatme [OPTION]
  ... via IPv6 and IPv4 in parallel while printing IPv6 before IPv4. Parallized
  only if /dev/shm and mktemp are available. Errors are silently ignored.
  Scripts may cover all four possible cases with:

  ipvx=$(lookatme) # Either IPv6\nIPv4\n, IPv6\n, IPv4\n, or empty.
  ipv6=$(echo "$ipvx" | grep -F :) # IPv6 or empty.
  ipv4=$(echo "$ipvx" | grep -F .) # IPv4 or empty.

  Security? ... make sure that:

  LOOKATME_OVER=https
  LOOKATME_FROM=<trustful-host>
  LOOKATME_DUDE=<trustful-ca-cert>

OPTIONs:
  -6, --ipv6     ... via IPv6 only.
  -4, --ipv4     ... via IPv4 only.

  -h, --help     Print help.
  -v, --version  Print version.

Environment variables:
  LOOKATME_OVER  http
  LOOKATME_FROM  ipvx.qu1x.org
  LOOKATME_DUDE  [CA_CERT]
  LOOKATME_HERE  [INTERFACE]
  LOOKATME_FAST  2

Server

An nginx server block may be:

server {
	listen 80;
	listen [::]:80;
	server_name ipvx.qu1x.org ipv6.qu1x.org ipv4.qu1x.org;
	default_type text/plain;
	return 200 "$remote_addr\n";
}

With following DNS records:

• ipvx.qu1x.org: A and AAAA for lookatme.
• ipv6.qu1x.org: AAAA only for IPv6 with web browser.
• ipv4.qu1x.org: A only for IPv4 with web browser.

License

Copyright (c) 2017, 2019 Rouven Spreckels n3vu0r@qu1x.org

Usage of the works is permitted provided that this instrument is retained with the works, so that any entity that uses the works is notified of this instrument.

DISCLAIMER: THE WORKS ARE WITHOUT WARRANTY.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the works by you shall be licensed as above, without any additional terms or conditions.