Add support for MX and SRV records in pdns provider

[saravanan30erd]

Description

This PR enables MX and SRV record support for PowerDNS provider in ExternalDNS. Especially for PowerDNS API, it requires explicit trailing dot for records having FQDN such as CNAME, MX, SRV, etc.. For CNAME record, its already covered here https://github.com/kubernetes-sigs/external-dns/blob/master/provider/pdns/pdns.go#L317-L318 so I added trailing dot for MX and SRV records now.

Errors Fixed

Error from PDNS API for SRV record creation

level=debug msg="PDNS API response:
level=fatal msg="Failed to do run once: Status: 422 Unprocessable Entity, Body: {\"error\": \"Record _service._tls.example.com./SRV '100 1 443 service.example.com': Not in expected format (parsed as '100 1 443 service.example.com.')\"}"

Error from PDNS API for MX record creation

level=fatal msg="Failed to do run once: Status: 422 Unprocessable Entity, Body: {\"error\": \"Record test.example.com./MX '10 mailhost1.example.com': Not in expected format (parsed as '10 mailhost1.example.com.')\"}

The above errors is fixed by this PR.

Fixes #3930 #4267

Checklist

• Unit tests updated
• End user documentation updated

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[k8s-ci-robot]

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[mloiseleur]

I'm not sure to understand the context of this PR.
Are you saying that, with this PR, it adds a needed trailing dot but it's still failing on PDNS ?
Or are you saying that, with this PR, the added trailing dot fix the issue observed with PDNS ?

Anyway, no PR on the code merge without test.
So would you please update the tests accordingly ?

[saravanan30erd]

@mloiseleur

are you saying that, with this PR, the added trailing dot fix the issue observed with PDNS ?

Yes.

PDNS API expects trailing dot for both these MX and SRV records. Without trailing dots, we are getting the errors mentioned in this issue #3930

I have added required trailing dots for these two records now same as CNAME and ALIAS records, after adding trailing dots we can create MX and SRV records in PDNS using external dns without any issues. Trailing dots are added already to CNAME and ALIAS records here https://github.com/kubernetes-sigs/external-dns/blob/master/provider/pdns/pdns.go#L317-L318

[mloiseleur]

@saravanan30erd Then wdyt of rewriting in this PR description "Errors to be fixed" with something like "Fixed errors" ?

Anyway, once it's tested, it can be reviewed.

[saravanan30erd]

@mloiseleur

Then wdyt of rewriting in this PR description "Errors to be fixed" with something like "Fixed errors" ?

Done, changed the PR description.

Anyway, once it's tested, it can be reviewed.

Sure, will add the tests.

[saravanan30erd]

@mloiseleur I have updated the test cases for this change. Please review it, thanks.

[mloiseleur]

/lgtm

[saravanan30erd]

Hi @mloiseleur Thanks for the review.

Is there anything I can do on my end to help move it forward? Please let me know if there's anything I can assist with.

[mloiseleur]

/ok-to-test

[mloiseleur]

@saravanan30erd One of the other maintainer will review it when he has time.

BTW, we have started the process to move the providers out of tree. Feel free to host your own pdns provider.

[saravanan30erd]

Thanks, bot told to assign it to @Raffo so assigning it.

Once this PR has been reviewed and has the lgtm label, please assign raffo for approval.

/assign @Raffo

[saravanan30erd]

@Raffo @szuecs When you have a moment, kindly please review this PR.

[saravanan30erd]

@Raffo Gentle Reminder. I wanted to kindly check if you’ve had a chance to review this PR.

[Raffo]

/approve

[k8s-ci-robot]

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