godyn

README

Cloud Dynamic DNS

This project contains a simple Dynamic DNS client that can be used with cloud services. It simply gets your current IP address and sets it to DNS records in backing DNS services. It will do it's best to make sure that the DNS record is always there and set to the desired value, even if something or someone updates or deletes it. It is intended to be used where public internet IPs are assigned dynamically, such as home networks.

Currently godyn only supports Google Cloud Platform.

Forked from https://github.com/ianlewis/cloud-dyndns-client

Prerequisites

godyn requires Go 1.8.

Install

You can install Go by following these instructions.

godyn is written in Go, so if you have Go installed you can install it with go install:

go install git.narnian.us/lordwelch/godyn@latest

This will download the code, compile it, and leave an godyn binary in $GOPATH/bin.

Usage

You need to set set up a DNS provider. Currently only Google Cloud Platform is supported.

Google Cloud Platform

Set up the client to use GCP by first creating a service account.

1. Create a GCP service account

SA_EMAIL=$(gcloud iam service-accounts --format='value(email)' create cloud-dyndns-client)

1. Create a JSON key file associated with the new service account

gcloud iam service-accounts keys create service-account.json --iam-account=$SA_EMAIL

1. Add an IAM policy to the service account for the project.

PROJECT=$(gcloud config list core/project --format='value(core.project)')
gcloud projects add-iam-policy-binding $PROJECT --member serviceAccount:$SA_EMAIL --role roles/dns.admin

Configuration

Create a config.json for the client. Enter the domain name you want to update, the GCP project ID, and Cloud DNS managed zone name. Multiple domains can be added as part of the configuration.

{
  "domains": {
    "mydomain.example.com": {
      "ip4": true,
      "ip6": false,
      "provider": "gcp",
      "provider_config": {
         "project_id": "example-project",
         "managed_zone": "example-zone",
      }
    }
  }
}

Running the client

Start the app and provide the path to the config.json. You need to specify the service account key in the GOOGLE_APPLICATION_CREDENTIALS environment variable.

export GOOGLE_APPLICATION_CREDENTIALS=/path/to/service-account.json
./cloud-dyndns-client -config config.json

Deploy the client to Kubernetes

1. Create a secret for the json key file

kubectl create secret generic cloud-dyndns-client-service-account --from-file=service-account.json

1. Deploy the client

kubectl apply -f kubernetes/deploy.yaml