DDNS

DDNS is a command line tool that maintains entries in a Route53 hosted zone in sync with the EC2 instances in a scaling group.

It does that by querying all pending and running EC2 instances with a specified tag and creating entries in a specified hosted zone. It will also remove all entries without a corresponding running EC2 instance.

Command Line Arguments

• --tag: Specify the tag and value to use when querying for EC2 instances. Format tag=value.
• --domain: Specify the Route53 domain where the entries will be created. DDNS will find the hosted zone associated with the domain.
• --prefix: Prefix to add to the Route53 entries. If the IP address of an instance is 127.0.0.1 the entry will be <prefix>127-0-0-1.<domain>. Default ddns-.
• --interval: Interval at which the DDNS will sync the Route53 entries with the EC2 instances. See https://golang.org/pkg/time/#ParseDuration for format. Default 30s.
• --debug: Enable debug logging.

The command line parameters can also be controlled with an environment variable of the form DDNS_<parameter_name>.

Development

DDNS relies on Glide to version its dependencies. After installing Glide simply run glide install to download the dependencies.

To build DDNS run make build.