# Issue
The previous fix had backwards compatibility issues and treated
uppercase Unicode incorrectly.
# Resolution
* Don't call strings.ToUpper() on Unicode strings. Only call it on the
output of ToASCII.
* Fix BIND's "filenameformat" to be more compatible (only breaks if you
had uppercase unicode in a domain name... which you probably didn't)
* Change IDN to ASCII in most places (Thanks for the suggestion,
@KaiSchwarz-cnic!)
* Update BIND documentation
## Summary
This PR adds a new domain modifier `IGNORE_EXTERNAL_DNS()` that
automatically detects and ignores DNS records managed by Kubernetes
[external-dns](https://github.com/kubernetes-sigs/external-dns)
controller.
**Related Issue:** This addresses the feature request discussed in
StackExchange/dnscontrol#935 (Idea: Ownership system), where
@tlimoncelli indicated openness to accepting a PR for this
functionality.
## Problem
When running DNSControl alongside Kubernetes external-dns, users face a
challenge:
- **external-dns** dynamically creates DNS records based on Kubernetes
Ingress/Service resources
- Users cannot use `IGNORE()` because they cannot predict which record
names external-dns will create
- Using `NO_PURGE()` is too broad - it prevents DNSControl from cleaning
up any orphaned records
The fundamental issue is that `IGNORE()` requires static patterns known
at config-time, but external-dns creates records dynamically at runtime.
## Solution
`IGNORE_EXTERNAL_DNS()` solves this by detecting external-dns managed
records at runtime:
```javascript
D("example.com", REG_CHANGEME, DnsProvider(DSP_MY_PROVIDER),
IGNORE_EXTERNAL_DNS(), // Automatically ignore external-dns managed records
A("@", "1.2.3.4"),
CNAME("www", "@")
);
```
### How It Works
external-dns uses a TXT record registry to track ownership. For each
managed record, it creates a TXT record like:
- `a-myapp.example.com` → TXT containing
`heritage=external-dns,external-dns/owner=...`
- `cname-api.example.com` → TXT containing
`heritage=external-dns,external-dns/owner=...`
This PR:
1. Scans existing TXT records for the `heritage=external-dns` marker
2. Parses the TXT record name prefix (e.g., `a-`, `cname-`) to determine
the managed record type
3. Automatically adds those records to the ignore list during diff
operations
## Changes
| File | Purpose |
|------|---------|
| `models/domain.go` | Add `IgnoreExternalDNS` field to DomainConfig |
| `pkg/js/helpers.js` | Add `IGNORE_EXTERNAL_DNS()` JavaScript helper |
| `pkg/diff2/externaldns.go` | Core detection logic for external-dns TXT
records |
| `pkg/diff2/externaldns_test.go` | Unit tests for detection logic |
| `pkg/diff2/handsoff.go` | Integrate external-dns detection into
handsoff() |
| `pkg/diff2/diff2.go` | Pass IgnoreExternalDNS flag to handsoff() |
| `commands/types/dnscontrol.d.ts` | TypeScript definitions for IDE
support |
| `documentation/.../IGNORE_EXTERNAL_DNS.md` | User documentation |
## Design Philosophy
This follows DNSControl's pattern of convenience builders (like
`M365_BUILDER`, `SPF_BUILDER`, `DKIM_BUILDER`) that make complex
operations simple. Just as those builders abstract away implementation
details, `IGNORE_EXTERNAL_DNS()` abstracts away the complexity of
detecting external-dns managed records.
## Testing
All unit tests pass:
```
go test ./pkg/diff2/... -v # Tests detection logic
go test ./pkg/js/... # Tests JS helpers
go build ./... # Builds successfully
```
## Caveats Documented
- Only supports TXT registry (the default for external-dns)
- Requires external-dns to use default naming conventions
- May need updates if external-dns changes its registry format
---------
Co-authored-by: Tom Limoncelli <6293917+tlimoncelli@users.noreply.github.com>
# Issue
Fixes https://github.com/StackExchange/dnscontrol/issues/3842
CC @das7pad
# Resolution
Convert domain.Name to IDN earlier in the pipeline. Hack the --domains
processing to convert everything to IDN.
* Domain names are now stored 3 ways: The original input from
dnsconfig.js, canonical IDN format (`xn--...`), and Unicode format. All
are downcased. Providers that haven't been updated will receive the IDN
format instead of the original input format. This might break some
providers but only for users with unicode in their D("domain.tld").
PLEASE TEST YOUR PROVIDER.
* BIND filename formatting options have been added to access the new
formats.
# Breaking changes
* BIND zonefiles may change. The default used the name input in the D()
statement. It now defaults to the IDN name + "!tag" if there is a tag.
* Providers that are not IDN-aware may break (hopefully only if they
weren't processing IDN already)
---------
Co-authored-by: Jakob Ackermann <das7pad@outlook.com>
