# Chrony NTP Server Add-on for Home Assistant

This add-on provides an NTP (Network Time Protocol) server and client using Chrony, enabling accurate time synchronization for your Home Assistant installation and local network devices.

## Features

- **NTP Client**: Synchronizes time from configurable upstream NTP servers
- **NTP Server**: Serves accurate time to devices on your local network
- **Lightweight**: Uses Chrony, a versatile and efficient NTP implementation
- **Multi-architecture**: Supports amd64 & aarch64

## Configuration

### Options

| Option              | Description                                                 | Default                                   |
| ------------------- | ----------------------------------------------------------- | ----------------------------------------- |
| `ntp_pools`         | List of NTP pools (DNS names resolving to multiple servers) | pool.ntp.org                              |
| `ntp_servers`       | List of individual NTP servers                              | time.google.com                           |
| `allow_clients`     | Networks allowed to query this NTP server                   | 192.168.0.0/16, 10.0.0.0/8, 172.16.0.0/12 |
| `enable_ntp_server` | Enable NTP server mode                                      | true                                      |
| `detailed_logging`  | Enable detailed chrony logs (measurements, statistics)      | false                                     |

### NTP Pools vs Servers

- **Pools** (`ntp_pools`): DNS names that resolve to multiple NTP servers (e.g., pool.ntp.org). Chrony will automatically discover and use multiple servers from the pool. Use `maxsources` to limit how many servers to use from each pool.
- **Servers** (`ntp_servers`): Individual NTP server addresses (e.g., time.google.com). Use these for specific servers you want to always query.

### Example Configuration

```yaml
ntp_pools:
  - pool: "pool.ntp.org"
    iburst: true
    maxsources: 4
  - pool: "time.cloudflare.com"
    iburst: true
ntp_servers:
  - server: "time.google.com"
    iburst: true
allow_clients:
  - "192.168.1.0/24"
enable_ntp_server: true
detailed_logging: false
```

## Installation

1. Add this repository to your Home Assistant add-on store
2. Install the "Chrony NTP Server" add-on
3. Configure the add-on options as needed
4. Start the add-on

## Usage

Once running, the add-on will:

1. Synchronize time from configured upstream NTP servers
2. If `enable_ntp_server` is true, serve time to clients on allowed networks via UDP port 123

### Configuring Clients

Point your network devices to use your Home Assistant's IP address as their NTP server.

## Support

For issues and feature requests, please open an issue on the repository.