feat(registry/txt): enable support for SRV and NAPTR

[alexbakker-quandago]

What does it do ?

This enables support for SRV and NAPTR in the TXT registry.

Motivation

We'd like to have external-dns clean up old SRV and NAPTR records.

More

• Yes, this PR title follows Conventional Commits
• Yes, I added unit tests
• Yes, I updated end user documentation accordingly

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[k8s-ci-robot]

Hi @alexbakker-quandago. Thanks for your PR.

I'm waiting for a github.com member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[ivankatliarchuk]

You may need to share more information why this constants added here. TXT registry does supports SRV records. So not too sure what is reason of updating the method.

Maybe worth to rename a method and add a description what is for. Hard to say

[alexbakker-quandago]

Without this change, SRV and NAPTR records are not cleaned up when using sync mode.

[ivankatliarchuk]

I don't have NAPTR records in my environment, but quite few SRV records. Not come across this problem. Could you share manifests so I could try to reproduce the problem?

[alexbakker-quandago]

Sure, no problem. Steps to reproduce:

• Start external-dns with the following arguments:

  --log-level=debug
  --log-format=text
  --interval=1m
  --source=service
  --source=ingress
  --source=crd
  --policy=sync
  --registry=txt
  --txt-owner-id=some-owner
  --txt-prefix=extdns-%{record_type}-
  --domain-filter=your-zone.example.com
  --provider=aws
  --zone-id-filter=REDACTED
  --managed-record-types=A
  --managed-record-types=AAAA
  --managed-record-types=CNAME
  --managed-record-types=NAPTR
  --managed-record-types=SRV
  --aws-zone-match-parent
  --aws-assume-role=arn:aws:iam::REDACTED:role/REDACTED
  

• Create a DNSEndpoint with an SRV record. For example:

  apiVersion: externaldns.k8s.io/v1alpha1
  kind: DNSEndpoint
  metadata:
    name: test-srv
    namespace: default
  spec:
    endpoints:
    - dnsName: _sip._udp.your-zone.example.com
      recordTTL: 180
      recordType: SRV
      targets:
      - 1 50 5060 sip1-n1.your-zone.example.com
      - 1 50 5060 sip1-n2.your-zone.example.com

• Watch external-dns create the record
• Delete the DNSEndpoint
• Notice that the SRV and related TXT record are not deleted from Route53

[ivankatliarchuk]

/ok-to-test

[coveralls]

Pull Request Test Coverage Report for Build 20176576968

Details

• 0 of 0 changed or added relevant lines in 0 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage remained the same at 78.688%

---

Totals
Change from base Build 20163464704:	0.0%
Covered Lines:	16013
Relevant Lines:	20350

---

💛 - Coveralls

[ivankatliarchuk]

So I tested with following arguments

go run main.go \
    --provider=aws \
    --registry=txt \
    --source=service \
    --log-level=debug \
    --managed-record-types=A \
    --managed-record-types=AAAA \
    --managed-record-types=SRV \
    --txt-owner-id=default \
    --fqdn-template='{{ if eq .Spec.Type "NodePort" }}{{ range .Spec.Ports }}{{ .Name }}local.tld{{printf "," }}{{end}}{{ end }}'

And manifest

apiVersion: v1
kind: Service
metadata:
  name: test-nodeport
spec:
  type: NodePort
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30394

Records created

When I changed manifest slightly to modify the SRV record

```yml
apiVersion: v1
kind: Service
metadata:
  name: test-nodeport
spec:
  type: NodePort
  selector:
    app: my-app
  ports:
  - port: 80
    targetPort: 80
    nodePort: 30398

Following error appear

DEBU[0000] Couldn't parse 0 50 30398 local.tld. as an IP address: ParseAddr("0 50 30394 local.tld."): unexpected character (at " 50 30394 local.tld.") comparisonTargets="0 50 30394 local.tld." targets="0 50 30398 local.tld."

With the fix, the problem dissapear and SRV records modified

[ivankatliarchuk]

Tested with CRD #6023 (comment). Works as well

created

modified

[ivankatliarchuk]

Coul you update tutorial https://github.com/kubernetes-sigs/external-dns/blob/master/docs/tutorials/crd.md with SRV and NAPTR example please?