NearlyFreeSpeech.net Dynamic DNS Utility

Overview

The following provides a utility to update a NearlyFreeSpeech.NET DNS record with a dynamic IP address. Invoking this utility will perform the following:

• Selecting a random provider to query for a public IP of the running host.
• Query a NearlyFreeSpeech.NET domain for a configured IP on a A record.
• Compare the address, and update if they do not match.
• (optional) Cache the detected public address set on NearlyFreeSpeech.NET for a couple of days (configurable) to limit API requests.

Requirements

• Python 3.8+
• PyYAML
• Requests 2.30.0+

Installation

This tool can be installed using pip:

pip install nfsn-ddns
 (or)
python -m pip install nfsn-ddns

Usage

This tool can be invoked from a command line using:

nfsn-ddns --help
 (or)
python -m nfsn-ddns --help

Configuration

This utility can be configured using a file, command line arguments or environment variables. An example configuration file (config.yaml) is as follows:

nfsn-ddns:
  api-login: <api-login>
  api-token: <api-token>
  domains:
    - <domain>
  timeout: 10

A user can use a combination of ways to configure this utility. For example, most options can be configured from the command line, but some options (such as the API token) can be configured from an environment variable:

export NFSN_DDNS_API_TOKEN=myapitoken
nfsn-ddns --api-login myaccount --ddns-domain ddns.example.com

All available configuration options are listed as follows:

Essential Options
API Login	The login/account of the NearlyFreeSpeech.NET user. This is used to authenticate API requests. Command line option: --api-login Configuration key: api-login (str) Environment variable: NFSN_DDNS_API_LOGIN
API Token	The token to use when authenticating API requests. Members can acquire an API token by viewing their profiles and selecting Manage API Key. In this page, users can request to generate an API token. Command line option: --api-token Configuration key: api-token (str) Environment variable: NFSN_DDNS_API_TOKEN
DDNS Domains	The DNS resource to update, which includes the DNS record which to update with a dynamically detected IP address, along with its domain. For example: ddns.example.com Multiple domains can be provided, for users who want a DDNS record across multiple domains (although the use of CNAME's are recommended when attempting to updated multiple records for a single domain). Command line option: --ddns-domain Configuration key: domains (str-list) Environment variable: NFSN_DDNS_DOMAINS (;-separated)
Additional Options
Cache	Configure whether a detected public IP will be cached into a local file. his feature can be used to avoid NFSN API calls if it is believed the public IP of a host is believed to have not changed. After a successful verification of a configured DNS record, the detected public IP can be stored in a cache file for future considerations. Next time this utility runs and detects a public IP address, if the address matches that of the cached file, no API requests to NFSN will be made. The cache will be considered a valid source of information for configured number of days (see "Cache Days"). By default, this setting is not enabled (except in container environments). Command line option: --cache Configuration key: cache (bool) Environment variable: NFSN_DDNS_CACHE
Cache Days	When using the cache capability, this value configures the total number of days before the cache is considered to be stale. A stale cache will cause this utility to perform an API request with NFSN to verify the DNS record matches. By default, a cache is considered valid for seven (7) days. Command line option: --cache-days Configuration key: cache-days (int) Environment variable: NFSN_DDNS_CACHE_DAYS
Cache File	When using the cache capability, the specific file where cached content is stored if set by this option. By default, the cache file location used will be the first available path that is writable by this utility: /run/nfsn-ddns/cached-ip (or) /run/user/(UID)/cached-ip (or) nfsn-ddns-cached-ip Command line option: --cache-file Configuration key: cache-file Environment variable: NFSN_DDNS_CACHE_FILE
IP API Endpoints	IP API endpoints are web services used to help determine the public IP address of the instance running this utility. The detected IP will be used to update the configured DNS record. The endpoint used is chosen at random each run. If a given endpoint cannot be accessed, other endpoints are used until an IP address is provided or all endpoints have been exhausted. The default endpoints used are as follows: https://api.ipify.org https://checkip.amazonaws.com/ https://ifconfig.me/ip https://ipinfo.io/ip https://trackip.net/ip Users can override what endpoints to use by configuring this option. Configuration key: myip-api-endpoints (str-list) Environment variable: NFSN_DDNS_MYIP_API_ENDPOINTS (;-separated)
Timeout	Configures the timeout (in seconds) until any requests to external sources (i.e. NFSN API or IP providers) are considered timed out. The default timeout for all requests is configured to ten (10) seconds. Command line option: --timeout Configuration key: timeout Environment variable: NFSN_DDNS_TIMEOUT
Advanced Options
NFSN API Endpoint	The API endpoint for NearlyFreeSpeech.NET. In almost all cases, this option never needs to be changed. However, the option is provided if a use case requires a different endpoint to be used. This value is configured to https://api.nearlyfreespeech.net/dns by default. Configuration key: nfsn-api-endpoint (str) Environment variable: NFSN_DDNS_NFSN_API_ENDPOINT

Docker

This project supports multiple ways to use this utility inside a Docker environment. A recommended choice is to use a pre-built image available from GitHub's container registry.

Pre-built image

A pre-built image can be acquired using the following command:

docker pull ghcr.io/jdknight/nfsn-ddns

Prepare a configuration environment for this container by creating a file /etc/nfsn-ddns with the contents defined in env.default (users can use any path or filename they desire, as long as the following docker run command points to this file). Adjust these options to the configuration desired.

The container than can be run using the following command:

docker run --name nfsn-ddns --detach --restart unless-stopped \
    --env-file /etc/nfsn-ddns ghcr.io/jdknight/nfsn-ddns

Self-built image

Users who wish to manage their own image can do so with the Docker definitions found inside this repository. This can be done by cloning this repository on the host wanting to run the container. A Docker build can be run on the

docker build -t ghcr.io/jdknight/nfsn-ddns --detach -f docker/Dockerfile .

Then running the same docker run call mentioned above.

Self-managed Docker Compose

Users can also take advantage of the Docker compose definition. First, copy the environment template (env.default) to .nfsn-ddns.env, followed by editing required options.

cp env.default .nfsn-ddns.env

Next, load up the container using docker compose:

docker compose build
docker compose up --detach

Both Docker build calls will by default load a container with the PyPI version of nfsn-ddns. Users wanting to use the local implementation in their container can do so by performing a Docker build with the --build-arg local argument.

For example:

docker compose build --build-arg BUILD_MODE=local
docker compose up --detach