zabbix-domain-expiry

Monitor domain expiration dates using RDAP or WHOIS protocols.

Features

• (NEW) RDAP and WHOIS Support: Queries domain expiration via RDAP (preferred) with fallback to WHOIS.
• (NEW) JSON Output: Script outputs JSON for easy parsing by Zabbix.
• (NEW) Debug Mode: Detailed debug output for troubleshooting.

Requirements

• Zabbix Server/Agent: Version 6.4 or higher
• OS: GNU/Linux systems
• Shell Script Dependencies:
  • curl: For RDAP queries.
  • mktemp: For temporary files.
  • date: For date calculations.
  • whois: For WHOIS queries.
  • grep: For parsing output.
  • awk: For parsing WHOIS and RDAP data.
  • jq: For parsing RDAP JSON responses.

Tested on

• OS: RHEL/Rocky (bash) and Debian/Ubuntu (dash)
• Zabbix Server: 6.4
• Note: Shell script is mostly POSIX compliant so should be widely compatible

Installation (Zabbix server)

Install Dependencies

Ensure the required dependencies are installed on your system.

For RHEL/Rocky:

sudo dnf install -y epel-release
sudo dnf install -y curl coreutils whois grep gawk jq

For Debian/Ubuntu:

sudo apt update
sudo apt install -y curl coreutils whois grep gawk jq

Setup Steps

1. Clone the Repository:

   git clone https://github.com/a-stoyanov/zabbix-domain-expiry.git
   cd zabbix-domain-expiry
   

2. Copy shell script check_domain.sh to your Zabbix server external scripts dir (default: /usr/lib/zabbix/externalscripts/)
3. Make it executable (e.g. chmod +x /usr/lib/zabbix/externalscripts/check_domain.sh)
4. Import yaml template zbx_domain_expiry.yaml to your zabbix server
5. Create a host with a domain name (e.g: example.com) as the Host name and attach the template to the host

Upgrading

If you are upgrading from the old version just import/overwrite the existing template and copy/overwite the old shell script with new version

Configuration

Template Macros

The template uses the following macros, configurable at the host or template level:

Macro	Default Value	Description
{$EXP_CRIT}	7	Days remaining before triggering a HIGH (critical) alert.
{$EXP_WARN}	30	Days remaining before triggering a WARNING alert.
{$RDAP_SERVER}	(empty)	Specify which RDAP server to use. Default empty value will use IANA lookup.
{$WHOIS_SERVER}	(empty)	Specify which WHOIS server to use. Default empty value will use rfc-3912 lookup.

Template Items

The template includes the following items to monitor domain expiration:

Name	Key	Type	Value Type	Description
Days Left	check_domain.days_left	Dependent	Float	Number of days until the domain expires.
Days Since Expired	check_domain.days_since_expired	Dependent	Float	Number of days since the domain expired (0 if not expired).
Expire Date	check_domain.expire_date	Dependent	Text	Domain expiration date in YYYY-MM-DD format.
Message	check_domain.message	Dependent	Text	Status message returned by the script.
State	check_domain.state	Dependent	Text	Domain status: OK, WARNING, CRITICAL, or UNKNOWN.
Check Domain	check_domain.sh[...]	External	Text	Executes the external script to check domain status.

Template Triggers

The template defines the following triggers for alerting:

Name	Expression	Priority	Description
Domain Expiry: {HOST.HOST} - {ITEM.LASTVALUE2}	last(/Domain Expiry/check_domain.state)="UNKNOWN" and last(/Domain Expiry/check_domain.message)<>0	Not Classified	Alerts if the script cannot determine the domain's expiration status.
Domain Expiry: {HOST.HOST} has expired	last(/Domain Expiry/check_domain.state)="CRITICAL" and last(/Domain Expiry/check_domain.days_since_expired)>0 and last(/Domain Expiry/check_domain.expire_date)<>0	Disaster	Alerts if the domain has expired.
Domain Expiry: {HOST.HOST} will expire soon (Critical)	last(/Domain Expiry/check_domain.state)="CRITICAL" and last(/Domain Expiry/check_domain.days_left)<={$EXP_CRIT} and last(/Domain Expiry/check_domain.expire_date)<>0	High	Alerts if days remaining are below the critical threshold ({$EXP_CRIT}).
Domain Expiry: {HOST.HOST} will expire soon (Warning)	last(/Domain Expiry/check_domain.state)="WARNING" and last(/Domain Expiry/check_domain.days_left)<={$EXP_WARN} and last(/Domain Expiry/check_domain.expire_date)<>0	Warning	Alerts if days remaining are below the warning threshold ({$EXP_WARN}).

Script Usage

The check_domain.sh script can be run manually for testing:

./check_domain.sh -d example.com
./check_domain.sh -d example.com -r 'https://rdap.example.com' -s 'whois.example.com' -w 30 -c 7

Options:

• -d, --domain: Domain name to check (required).
• -w, --warning: Warning threshold in days (default: 30).
• -c, --critical: Critical threshold in days (default: 7).
• -r, --rdap-server: RDAP server URL (use "" for IANA lookup).
• -s, --whois-server: WHOIS server hostname (use "" for default lookup).
• -P, --path: Path to whois executable.
• -z, --debug: Enable debug output to stderr.
• -h, --help: Display help.
• -V, --version: Display version in JSON format.

Example Output:

{"state":"OK","days_left":365,"days_since_expired":0,"expire_date":"2026-06-24","message":"State: OK ; Days left: 365 ; Expire date: 2026-06-24"}

Debugging

• Enable debug mode in the script with -z:

  ./check_domain.sh -d example.com -z
  

• Check Zabbix logs for issues with script execution.
• Verify RDAP/WHOIS server availability and response format outside of script

Notes

• The script prioritizes RDAP for faster, structured queries but falls back to WHOIS if RDAP fails.
• WHOIS awk parsing supports various date formats but may fail if whois query returns non-standard responses (no awk pattern match).
• Rate limits on WHOIS servers may trigger UNKNOWN states; increase or use custom check interval to mitigate (the default 1d is very reasonable).
• For some specific TLDs (e.g: .uk, .br) RDAP URL paths may have to be adjusted due to non-standard URL format. See adjust_rdap_url() function, which already handles /uk/ path adjustment.

License

This project is licensed under the Apache License 2.0