on-ip-changed

On-IP-Changed is a small utility that periodically gets the IP of the system running this program and invokes handlers to notify what the change is.

Support both IPv4 and IPv6.

Config File

Full configuration example:

daemon:
  # tasks execution interval
  interval: 1m
  # if multiple getters, at most `concurrency`
  # randomly selected getters will be used.
  concurrency: 1
  # timeout out for getter and handler execution.
  timeout: 15s
  # notify the first IP address?
  # The first is what we get when we restart the daemon. if restarted 
  # frequently, handlers will be executed frequently too, with the same IP.
  initial: false

tasks:
  - name: test
    # if multiple getters, handlers will be executed if and only if when
    # a majority ( > a half ) of the getters return the same IP address.
    getters:
      - type: domain
        domain: example.com
    handlers:
      - shell: 
          command: echo --- $IP ---
    ipv6only: true
    ipv4only: true

(Environment) Variables

• $IP
• $IPv4
• $IPv6

Concepts

• Tasks Each contains getters and handlers.
• Getter A getter is an IP getter, which gets a kind of IP for localhost, website, router, domain, etc..
• Handler A handler is what should be doing when we get an IP.

You can write your own getters and handlers easily.

Getters

Domain

Domain getter gets the IP of a domain.

This can be useful, for example, when you use dynamic DNS and you want to update the WireGuard peer's Endpoint, since it doesn't update automatically.

Example configuration:

type: domain
domain: home.example.com

Website

Website getter gets your network's outbound IP address reported by a website. This is usually used to get your public IP address, which can be used to update your DDNS record.

Example configuration:

type: website
url: domain.to.get.my.ip.address.example.com
format: json
path: ip
# user_agent: ???

Format

Format specifies what content type is returned from that website and how we should parse the content to get the IP address.

Can be one of:

• text

  The content is plain text IP address.

  path is not used.

• json

  The content is a JSON object containing a field specifying the IP.

  Use path to specify the path reaching to that field.

  For example, a JSON with this content:

  {
    "data": {
      "ip": "1.1.1.1"
    }
  }

  Then, the path should be data.ip.

• search

  This enables searching for the first IP address in the content using a regexp matching a single IPv4 address.

  path is not used.

  search currently doesn't work for IPv6 addresses.

List

Some example websites which can give you your IP address:

- type: website
  url: https://ifconfig.co/ip
  format: text
- type: website
  url: https://wtfismyip.com/text
  format: text
- type: website
  url: https://ip.cn/api/index?ip=&type=0
  format: json
  path: ip
- type: website
  url: https://myip.ipip.net/
  format: search
- type: website
  url: https://myip.com.tw/
  format: search
- type: website
  url: http://ip-api.com/line/?fields=query
  format: text
- type: website
  url: https://ip.sendev.cc
  format: text
- type: website
  url: https://api.ipify.org/
  format: text

Ifconfig

Ifconfig gets the IP address of an interface by its name.

Example configuration:

type: ifconfig
name: eth0

For IPv6 addresses, it current report the global unicast address only (not including unique local addresses).

Asus

Asus gets the WAN IP address of the Asus router family (not well tested).

Example configuration:

type: asus
address: 192.168.1.1
username: asus
password: asus

Getting the outbound IPv4 address from routers can be useful when you use VPN. Because website will report the IP address of your VPN server, which you mostly cannot control its port forwarding rules.

Handlers

Shell

Shell handler executes a shell command with IP passed by environment variable IP.

Example configuration:

shell:
  command: echo $IP

  # or

  command: |
    #!/bin/bash

    set -eu

    echo IP: $IP

  # or

  command:
    - my_ddns_updater
    - -c
    - --long-option
    - $IP

Additional arguments can be set:

• shell

  Specify what shell will be used when command is a string instead of an array.

  shell: fish

• env

  Additional environment variables.

  env:
    key: value
    foo: bar

• work_dir

  work_dir: ~/data/

  The working directory of the command.

  Home directory in style of ~ (no ~user) in the work_dir will be expanded to their respective directories.

HTTP

HTTP handler makes a request.

Example configuration:

http:
  endpoint: http://example.com
  args:
    ip: $IP
  headers:
    token: ttt
  method: GET
  body: Your IP changed to $IP.

The result URL will be: http://example.com/?ip=1.2.3.4 。

For example, you can use Chanify to notify your latest IP address.

DnsPod

DnsPod handler updates your DNS record of DnsPod.

Example configuration:

dnspod:
  token: 123,abcdefgh
  email: your@example.com
  domain: example.com
  record: subdomain

There should have been more DNS provider handlers...