cloudflare-ddns

Dynamic DNS with Cloudflare

Description

POSIX shell script (also using sed); acquires current host's IP and updates specified Cloudflare DNS entries with the Cloudflare API. Does not modify TTL or Proxy status.

Install

Clone this repository or just download cloudflare-ddns.sh and configure.

Example:

wget https://raw.githubusercontent.com/nickersonm/cloudflare-ddns/main/cloudflare-ddns.sh
nano cloudflare-ddns.sh

Configuration

Review and modify variable definitions in the Definitions section - minimal required changes are AUTH_KEY, DNS_ZONE, and DNS_RECORDS

# Definitions
## Account settings (required)
AUTH_EMAIL=""             # Cloudflare email; only required for Global API key usage
AUTH_TYPE="token"         # 'token' or 'global' https://dash.cloudflare.com/profile/api-tokens
AUTH_KEY="<apikey>"       # Relevant Cloudflare API key

## DNS record settings (required)
DNS_ZONE="<domainzone>"   # Cloudflare zone ID; retreive from the "Overview" tab of the domain dashboard
DNS_RECORDS="<[sub.]domain.tld>"            # Record(s) to point to this IP, in the form of `[sub.]domain.tld`

## Connection settings (defaults)
IP_V="4"                  # IP version to check and update: (4 | 6)
IP_QUERY="https://icanhazip.com https://api.ip.sb/ip https://api64.ipify.org https://ip.seeip.org/ https://api.my-ip.io/ip"

Usage

Use cron, /etc/periodic/, or similar to run regularly. For example:

sh cloudflare-ddns.sh   # Run once

chmod 770 cloudflare-ddns.sh         # Contains API key
doas mv cloudflare-ddns.sh /etc/periodic/15min
doas chown root:root /etc/periodic/15min/cloudflare-ddns.sh

Errors are output to stderr, information is output to stdout.