dyngo

README

dyngo

Sync a DigitalOcean/Cloudflare/Custom DNS entry with your public IP.

Why?

I created this because the domain I own was being managed in some cloud nameservers and I didn't want to pay for a DDNS service for another domain. Using this app, I can host my website at mydomain.com but also have a subdomain of my choosing (ie. dev.mydomain.com) point to my dev network hosted elsewhere behind a dynamic IP.

Installing

Compile

This project has only been tested with go1.11+. To compile just run go get -u github.com/gesquive/dyngo and the executable should be built for you automatically in your $GOPATH. This project uses go mods, so you might need to set GO111MODULE=on in order for go get to complete properly.

Optionally you can run make install to build and copy the executable to /usr/local/bin/ with correct permissions.

Download

You could download the latest release for your platform from github.

Once you have an executable, make sure to copy it somewhere on your path like /usr/local/bin or C:/Program Files/. If on a *nix/mac system, make sure to run chmod +x /path/to/dyngo.

Docker

You can also run dyngo from the provided Docker image and by providing a configuration file:

docker run -d -v $PWD/dyngo:/config dyngo:latest

While dyngo will technically run with the sample config, it won't have any domain to sync too. You will need to edit the config to add dns providers.

For more details read the Docker image documentation.

Precedence Order

The application looks for variables in the following order:

• command line flag
• environment variable
• config file variable
• default

So any variable specified on the command line would override values set in the environment or config file.

Config File

The application looks for a configuration file at the following locations in order:

• ./config.yml
• ~/.config/dyngo/config.yml
• /etc/dyngo/config.yml

Copy config.example.yml to one of these locations and populate the values with your own. Since the config contains a writable API token, make sure to set permissions on the config file appropriately so others cannot read it. A good suggestion is chmod 600 /path/to/config.yml.

If you are planning to run this app as a service/cronjob, it is recommended that you place the config in /etc/dyngo/config.yml. Otherwise, if running from the command line, place the config in ~/.config/dyngo/config.yml and make sure to set run_once: true.

Environment Variables

Optionally, instead of using a config file you can specify config entries as environment variables. Use the prefix DYNGO_ in front of the uppercased variable name. For example, the config variable sync-interval would be the environment variable DYNGO_SYNC_INTERVAL.

Usage

A service application that watches your external IP for changes and updates a DigitalOcean domain record when a change is detected

Usage:
  dyngo [flags]

Flags:
      --config string          Path to a specific config file (default "./config.yaml")
  -4, --ipv4                   Check for our WAN IPv4 address (default true)
  -6, --ipv6                   Check for our WAN IPv6 address (default true)
      --log-file string        Path to log file (default "/var/log/dyngo.log")
  -o, --run-once               Only run once and exit
  -i, --sync-interval string   The duration between DNS updates (default "60m")
      --version                Display the version number and exit

It is helpful to use the --run-once when first setting up to find any misconfigurations.

Optionally, a hidden debug flag is available in case you need additional output.

Hidden Flags:
  -D, --debug                  Include debug statements in log output

Cronjob

To run as a cronjob on an Ubuntu system create a cronjob entry under the user the app is run with. If running as root, you can copy services/dyngo.cron to /etc/cron.d/dyngo or copy the following into you preferred crontab:

  0  *  *  *  * /usr/local/bin/dyngo --run-once

Add any flags/env vars needed to make sure the job runs as intended. If not using arguments, then make sure the config file path is specified with a flag or can be found at one of the expected locations.

Service

By default, the process is setup to run as a service. Feel free to use upstart, systemd, runit or any other service manager to run the dyngo executable.

Example systemd & upstart scripts can be found in the services directory.

DNS Provider Configuration

Before configuring and running dyngo, make sure that the domain exists in your cloud account. Specifics can be found below.

digitalocean

DigitalOcean DNS provides excellent documentation on this adding domains to DNS.

• record: The record to set the IP on (ie. ddns.mydomain.com)
• token: The DigitalOcean personal access token. Token requires read/write permissions.

cloudflare

You will need to add your domain to Cloudflare before you can manage any records.

• record: The record to set the IP on (ie. ddns.mydomain.com)
• token: The Cloudflare API Token. API token requires at least the Zone.Zone:Read, Zone.DNS:Edit permissions.

custom

If your provider is not found above, it is possible to run a custom script as well. The custom DNS provider supports the following config options:

• record: The record to set the IP on (ie. ddns.mydomain.com)
• path: The relative path to the script
• args: Arguments to pass to the script when executing

Scripts should expect the following arguments when being executed:

• Record - the record value from the config example: custom.domain.com
• Record Type - example: A, AAAA
• IP Address - example: 192.168.1.100, 2001:cdba::3257:9652
• args - The args value from the config

For example, a config with the following value:

dns_providers:
  name: custom
  # The domain record to pass to the script
  record: custom.domain.com
  # The relative path to the script
  path: path/to/custom_script.sh
  # The arguments to pass when executing the script
  args: "-D"

would possible result in the following call:

path/to/custom_script.sh custom.domain.com A 192.168.10.10 -D

Documentation

This documentation can be found at github.com/gesquive/dyngo

License

This package is made available under an MIT-style license. See LICENSE.

Contributing

PRs are always welcome!