# realDynDNS

RealDynDNS aims to be a replacement to "classical" dynDNS solutions that offer a subdomain. Instead realDynDns actually changes your DNS entries.

This service requires your DNS provider to expose an API that allows your DNS entries to be changed.
A service that provides your current external IP is also required.

## Configuration

The configuration is done via a YAML file called `config.yaml`. The following example shows the configuration for a domain with two subdomains.

Configuration of the IP provider and the DNS provider is mandatory.

The `check_interval` is mandatory and follows the cron syntax including seconds. It defines how often the IP is checked and the DNS entries are updated. If you don't own the external ip provider, please be nice and don't set the interval too low.

You may configure multiple top level domains with multiple subdomains. If you also want the top level domain to be updated, add it to the subdomains list with an `@`.

```yaml
ip_provider:
  type: plain
  config:
    url: https://ifconfig.me
dns_provider:
  type: ionos
  config:
    api_key: <your-api-key>
    base_url: https://api.hosting.ionos.com/dns
notification_provider:
  type: gotify
  config:
    url: <your-gotify-host>
    token: <your-token>
    priority: 0
domains:
  - tld: example.com
    subdomains:
      - "@"
      - www
check_interval: 0 0 0/6 * * * *
mode: Scheduled
log_level: info
```

The config file is expected to be in the same directory as the binary and called `config.yaml`. For the OCR image, the root directory is `/app`.

## DNS Providers

The DNS provider abstracts the API of your DNS provider. Currently the following providers are supported:

### IONOS

IONOS requires two configuration parameters. You can get your API key [here](https://developer.hosting.ionos.com/docs/getstarted).

```yaml
api_key: <your-api-key>
base_url: https://api.hosting.ionos.com/dns
```

## External IP Providers

The external IP provider is used to get your current external IP. Currently the following providers are supported:

### Plain

Any provider that returns your IP as plain text can be used. The following configuration is required:

```yaml
url: <your-providers-URL>
```

Examples for providers are:

- https://ifconfig.me
- https://api.ipify.org

## Notification Providers

The notification provider is used to send notifications whena IP address changes and a DNS record is updated.

### Console

The console notification provider is used to print the notification to the console. This is the default notification provider.

### Gotify

The Gotify notification provider is used to send notifications to a Gotify server.

```yaml
url: <your-gotify-host>
token: <your-token>
priority: 0
```

The priority must be between 0 and 4.

## Mode Selection

Two modes are available:

### RunOnce

The RunOnce mode is used to run the application once and exit. This is useful when providing your own external scheduler, like cron.

Set the `mode` to `RunOnce`.

### Scheduled

The Scheduled mode is used to run the application in a scheduled interval.

Set the `mode` to `Scheduled` and provide a cron expression for the `check_interval`.