This container automates the generation of DNS zone files for CoreDNS (or BIND) by synchronizing data from NetBox. It fetches IPAM data (active IPs with DNS names) and DNS Plugin records.

Features

Automated Synchronization: Periodically fetches data from NetBox (Default: 10 minutes).
Fail-Safe Operation: If NetBox is unreachable or returns errors, the existing zone files are preserved to prevent NXDOMAIN issues.
Dual Zone Support: Generates both Forward and Reverse (PTR) zones.
Intelligent Fallback: Automatically configures a fallback Nameserver if no NS records are defined in NetBox.

Configuration

Configuration is handled entirely via environment variables.

Required Variables

Variable	Description
`NETBOX_URL`	The full URL to the NetBox instance (e.g., `http://netbox.local`).
`NETBOX_TOKEN`	The API Token for authentication (Read-Only permissions are sufficient).

Optional Variables

Variable	Default	Description
`REFRESH_INTERVAL`	`600`	Synchronization interval in seconds.
`ZONE_NAME`	`klenzel.net`	The DNS zone name to manage.
`REVERSE_ZONE_NAME`	`172.in-addr.arpa`	The reverse lookup zone name.
`OUTPUT_FILE_FWD`	`/zones/db.klenzel.net`	Path inside the container for the forward zone file.
`OUTPUT_FILE_REV`	`/zones/db.reverse.arpa`	Path inside the container for the reverse zone file.
`FALLBACK_NS_HOSTNAME`	`fks-01-cl-cdns`	Hostname used for NS record if none exist in NetBox.
`FALLBACK_NS_IP`	`172.25.16.152`	IP address for the fallback NS glue record.

Usage

Docker

Build the image:
```
docker build -t local/dns-sync .
```

Run with environment variables:

docker run -d \
  --name klzDNS-worker \
  --restart unless-stopped \
  --net=container:klzDNS-coredns \
  -v klzDNS-data:/zones \
  -e NETBOX_URL="http://172.30.242.99" \
  -e NETBOX_TOKEN="your-secret-token" \
  local/dns-sync

Using a `.env` file

Create a .env file based on the example:

cp .env.example .env
# Edit .env and add your credentials

Run the container referencing the file:

docker run -d \
  --name klzDNS-worker \
  --restart unless-stopped \
  --net=container:klzDNS-coredns \
  -v klzDNS-data:/zones \
  --env-file .env \
  local/dns-sync

README.md

CoreDNS NetBox Sync