# Fix: NetBird extra-dns-labels not being applied to pods
## Problem
The `netbird.io/extra-dns-labels` annotation was not working when
applied to pods. Despite the webhook detecting the annotation and adding
it to the NetBird container configuration, the extra DNS labels were not
appearing in the NetBird UI or being applied to registered peers.
## Root Cause
The pod webhook had two issues:
1. **Invalid setup key argument**: The webhook was passing
`--setup-key-file /etc/nbkey` to the NetBird client, but this file path
was never created. The setup key was already being passed via the
`NB_SETUP_KEY` environment variable, making the file-based approach
unnecessary and causing confusion in the client startup.
2. **NetBird CLI flag bug**: The webhook was using the
`--extra-dns-labels` command line flag, but NetBird has a known issue
([netbirdio/netbird#4282](https://github.com/netbirdio/netbird/issues/4282))
where this flag is not properly processed. The workaround is to use the
`NB_EXTRA_DNS_LABELS` environment variable instead.
## Solution
- Removed the `--setup-key-file` argument entirely since the setup key
is provided via environment variable
- Removed all command line arguments from the NetBird container
- Added `NB_EXTRA_DNS_LABELS` environment variable when the
`netbird.io/extra-dns-labels` annotation is present
- NetBird client now uses only environment variables for configuration,
which is more reliable and matches the pattern used by the NBRoutingPeer
controller
## Changes
**Before:**
```go
args := []string{
"--setup-key-file", "/etc/nbkey",
"-m", managementURL,
}
// ... add extra-dns-labels to args
```
**After:**
```go
envVars := []corev1.EnvVar{
{Name: "NB_SETUP_KEY", ValueFrom: ...},
{Name: "NB_MANAGEMENT_URL", Value: managementURL},
}
// ... conditionally add NB_EXTRA_DNS_LABELS to envVars
```
## Testing
1. Create a deployment with the `netbird.io/setup-key` and
`netbird.io/extra-dns-labels` annotations:
```yaml
annotations:
netbird.io/setup-key: my-setup-key
netbird.io/extra-dns-labels: "my-label,another-label"
```
2. Verify the environment variable is set:
```bash
kubectl get pod <pod-name> -o jsonpath='{.spec.containers[?(@.name=="netbird")].env[*]}' | jq .
```
3. Check the NetBird UI to confirm the extra DNS labels appear on the
registered peer
4. Verify the NetBird container logs show successful registration
without errors
## References
- NetBird issue: https://github.com/netbirdio/netbird/issues/4282
- Documentation: [Extra DNS
Labels](https://docs.netbird.io/how-to/routing-traffic-to-private-networks#extra-dns-labels)
---
This fix ensures that the `netbird.io/extra-dns-labels` annotation works
as documented and provides a more robust configuration method by using
environment variables consistently across all NetBird deployments in the
operator.
- It adds a helm chart that will be hosted in the Github pages URL of this repository
- an admission controller operator
- Basic documentation for installing the operator, configuring CRDs and example pod configuration
Christian De LeonandGitHub
M Essam Hamed
Hakan Sariman