myip

Dead simple server that will just return your IP address.

Building

# With Nix
nix build

# With Cargo
cargo build --release

Configuration

Configuration is done via environment variables:

Variable	Required	Description
MYIP_LISTEN_V4	One of V4/V6	IPv4 address and port to listen on (e.g., 0.0.0.0:1234)
MYIP_LISTEN_V6	One of V4/V6	IPv6 address and port to listen on (e.g., [::]:1234)
MYIP_HUMANE	No	true (default): return IP as text; false: return raw bytes (4 for IPv4, 16 for IPv6)
MYIP_MODE	No	dontwait (default): single write attempt; writeall: retry until full buffer is written

You must set exactly one of MYIP_LISTEN_V4 or MYIP_LISTEN_V6. Set to none to explicitly disable.

Usage

Standalone

# Start the server
MYIP_LISTEN_V4=0.0.0.0:3000 ./myip

# Query your IP
nc myip.example.com 3000
# Output: 203.0.113.42

# Or with telnet
telnet myip.example.com 3000

# Or through any browser, just visit the running server and usually your IP will be displayed, despite the fact that returned text is not valid HTTP.

# Raw binary output (for scripts)
MYIP_LISTEN_V4=0.0.0.0:3000 MYIP_HUMANE=false ./myip

NixOS Module

Add to your flake inputs:

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
    myip = {
      url = "github:youruser/myip";  # adjust URL
      inputs.nixpkgs.follows = "nixpkgs";
      #inputs.rust-overlay.follows = "rust-overlay";
      # ^ The build is done through rust-overlay, override if you want.
    };
  };
}

Apply overlays and import the module:

{ inputs, ... }:
{
  nixpkgs.overlays = [
    inputs.myip.overlays.default
  ];

  imports = [ inputs.myip.nixosModules.default ];
}

Configure instances:

{
  services.myip = {
    # Defaults for all instances
    enable = true;
    autostart = true;

    # IPv4 instances
    instances.v4 = {
      human = {
        listen = "0.0.0.0:3000";
      };
      machine = {
        listen = "0.0.0.0:3001";
        humane = false;
      };
    };

    # IPv6 instances
    instances.v6 = {
      human = {
        listen = "[::]:3000";
      };
    };
  };
}

This creates three systemd services: myip-v4-human, myip-v4-machine, and myip-v6-human.

Module Options

Global options (defaults for all instances):

Option	Type	Default	Description
enable	bool	true	Whether to enable instances by default
autostart	bool	true	Whether instances start on boot by default
package	package	pkgs.myip	The myip package to use

Per-instance options (services.myip.instances.v4.<name> or services.myip.instances.v6.<name>):

Option	Type	Default	Description
enable	bool	inherited	Whether to create this instance
autostart	bool	inherited	Whether to start on boot
listen	string	required	Address and port to listen on
mode	null or "dontwait"/"writeall"	null	Write mode
humane	null or bool	null	Human-readable output

License

MIT