fix(exoscale): handle apex DNS records

[natalie-o-perret]

1. external-dns info

This came in as a customer report (no direct cluster access), so I traced it through the source code.

Version: unconfirmed from the customer, but the bug is present in current master (dc28c3e).

Startup flags (from customer description, approximate):

--provider=exoscale
--source=service
--domain-filter=xxx.yy

Debug logs: not available. Based on the code path, EndpointZoneID returns "" for apex records so they are dropped before any change is scheduled. You would never see a CREATE xxx.yy line in the logs.

2. Kubernetes resources

Not available (proprietary infrastructure). The relevant annotation was:

external-dns.alpha.kubernetes.io/hostname: xxx.yy

3. DNS provider: existing vs expected records

Name	Type	Exists	Expected
www.xxx.yy	A	yes	yes, works fine
xxx.yy	A	no	yes, never created

4. TXT ownership records

Not available.

---

Demonstrating the bug with tests

I added tests that fail against master and pass after the fix. Here is the output against the unpatched code:

$ go test ./provider/exoscale/... -v -run "TestExoscaleApplyChanges_ApexRecord|TestEndpointZoneID_ApexRecord|TestExoscaleGetRecords"

=== RUN   TestExoscaleGetRecords
    exoscale_test.go:129: Error: Should be true     <- "foo.com" not found in Records() output
    exoscale_test.go:130: Error: Should be false    <- ".foo.com" IS present (Records() returns leading dot for apex)
--- FAIL: TestExoscaleGetRecords

=== RUN   TestExoscaleApplyChanges_ApexRecord
    exoscale_test.go:163: Error: "[]" should have 1 item(s), but has 0
--- FAIL: TestExoscaleApplyChanges_ApexRecord
panic: runtime error: index out of range [0] with length 0

FAIL    sigs.k8s.io/external-dns/provider/exoscale

After the fix:

$ go test ./provider/exoscale/... -v -run "TestExoscaleApplyChanges_ApexRecord|TestEndpointZoneID_ApexRecord|TestExoscaleGetRecords"

--- PASS: TestExoscaleGetRecords
--- PASS: TestExoscaleApplyChanges_ApexRecord
--- PASS: TestEndpointZoneID_ApexRecord
ok  sigs.k8s.io/external-dns/provider/exoscale

Note

This PR description was drafted with AI assistance (GitHub Copilot).

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[linux-foundation-easycla]

• ❌ - login: @natalie-o-perret / name: Natalie Perret . The commit (27c562a) is not authorized under a signed CLA. Please click here to be authorized. For further assistance with EasyCLA, please submit a support request ticket.

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[brutasse]

CLA Authorization should be in place now.

[ivankatliarchuk]

If there is a bug, please share information in the more receivable format https://github.com/kubernetes-sigs/external-dns/blob/master/docs/contributing/bug-report.md

[natalie-o-perret]

If there is a bug, please share information in the more receivable format https://github.com/kubernetes-sigs/external-dns/blob/master/docs/contributing/bug-report.md

Sure, will do 🙇‍♀️

[ivankatliarchuk]

Not related to this fix exoscale/egoscale#750 but worth to refresh provider in separate PR

• dependency bump
• add support for zone caching https://github.com/kubernetes-sigs/external-dns/tree/master/provider/blueprint
• add support for providers GetDomainFilter example PR feat(pdns): support GetDomainFilter interface #6234

[natalie-o-perret]

Not related to this fix exoscale/egoscale#750 but worth to refresh provider in separate PR

* dependency bump

* add support for zone caching https://github.com/kubernetes-sigs/external-dns/tree/master/provider/blueprint

* add support for providers GetDomainFilter example PR [feat(pdns): support GetDomainFilter interface #6234]

@ivankatliarchuk, there it is, #6371

Btw, for some reason, while I've done the auth thingy, which did work for my other PR, it doesn't seem the case for that PR here, do you happen to know why?

EasyCLA — Missing CLA Authorization.