PR to support RFC2136 multiple hosts.

[Jeremy-Boyle]

Description

Details in #4651

Fixes #4651
Fixes #3470

Checklist

• Unit tests updated
• End user documentation updated

[k8s-ci-robot]

Hi @Jeremy-Boyle. Thanks for your PR.

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[k8s-ci-robot]

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[Jeremy-Boyle]

Work has been completed All tests are succeeding,

I have build and tested the use cases for fail-over and load balancing options within a working lab environment.

Failover

time="2024-08-02T18:27:57Z" level=info msg="Created Dynamic Kubernetes client https://10.96.0.1:443"
time="2024-08-02T18:27:57Z" level=info msg="Configured RFC2136 with zones '[PRIVATE-DNS.com]' and nameservers '[HOST-1 HOST-2]'"
time="2024-08-02T18:27:57Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:27:57Z" level=debug msg="Fetching records from nameserver: HOST-1:53"
time="2024-08-02T18:27:59Z" level=warning msg="Last operation failed for nameserver HOST-1:53"
time="2024-08-02T18:27:59Z" level=warning msg="Last operation error message: failed to fetch records via AXFR: failed to connect for transfer: dial tcp HOST-1:53: i/o timeout"
time="2024-08-02T18:27:59Z" level=debug msg="Fetching records from nameserver: HOST-2:53"
time="2024-08-02T18:27:59Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:27:59Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tNS\tns1.PRIVATE-DNS.com."

Load balance

Round Robbin

time="2024-08-02T18:32:43Z" level=info msg="Created Dynamic Kubernetes client https://10.96.0.1:443"
time="2024-08-02T18:32:43Z" level=info msg="Configured RFC2136 with zones '[PRIVATE-DNS.com]' and nameservers '[HOST-1 HOST-2]'"
time="2024-08-02T18:32:43Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:32:43Z" level=debug msg="Fetching records from nameserver: HOST-1:53"
time="2024-08-02T18:32:43Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:32:43Z" level=info msg="All records are already up to date"
time="2024-08-02T18:32:53Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:32:53Z" level=debug msg="Fetching records from nameserver: HOST-2:53"
time="2024-08-02T18:32:53Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:33:03Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:33:03Z" level=debug msg="Fetching records from nameserver: HOST-1:53"
time="2024-08-02T18:33:03Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:33:03Z" level=info msg="All records are already up to date"
time="2024-08-02T18:33:14Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:33:14Z" level=debug msg="Fetching records from nameserver: HOST-2:53"
time="2024-08-02T18:33:14Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:33:14Z" level=info msg="All records are already up to date"
time="2024-08-02T18:33:25Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:33:25Z" level=debug msg="Fetching records from nameserver: HOST-1:53"
time="2024-08-02T18:33:25Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:33:25Z" level=info msg="All records are already up to date"

###Random

time="2024-08-02T18:38:02Z" level=info msg="Created Dynamic Kubernetes client https://10.96.0.1:443"
time="2024-08-02T18:38:02Z" level=info msg="Configured RFC2136 with zones '[PRIVATE-DNS.com]' and nameservers '[HOST-1 HOST-2 HOST-3]'"
time="2024-08-02T18:38:02Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:38:02Z" level=debug msg="Fetching records from nameserver: HOST-3:53"
time="2024-08-02T18:38:02Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:38:02Z" level=info msg="All records are already up to date"
time="2024-08-02T18:38:12Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:38:12Z" level=debug msg="Fetching records from nameserver: HOST-2:53"
time="2024-08-02T18:38:12Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:38:12Z" level=info msg="All records are already up to date"
time="2024-08-02T18:38:22Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:38:22Z" level=debug msg="Fetching records from nameserver: HOST-2:53"
time="2024-08-02T18:38:22Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:38:22Z" level=info msg="All records are already up to date"
time="2024-08-02T18:38:33Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:38:33Z" level=debug msg="Fetching records from nameserver: HOST-3:53"
time="2024-08-02T18:38:33Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:38:33Z" level=info msg="All records are already up to date"
time="2024-08-02T18:38:44Z" level=debug msg="Fetching records for '\"PRIVATE-DNS.com\"'"
time="2024-08-02T18:38:44Z" level=debug msg="Fetching records from nameserver: HOST-3:53"
time="2024-08-02T18:38:44Z" level=debug msg="Record=PRIVATE-DNS.com.\t86400\tIN\tSOA\topnsense.home.arpa. mail.opnsense.home.arpa. 2407231527 21600 3600 3542400 3600"
time="2024-08-02T18:38:55Z" level=info msg="All records are already up to date"

I can provide the image for testing if you would like, however when it goes to staging i believe the image can be used when its build via the ci.

Additionally if all hosts fail then the pod will crash like in its current state in master.

[mloiseleur]

Thanks for this PR @Jeremy-Boyle. It seems you are a big user of this provider.
I'm not sure to understand why you didn't use a reverse proxy to load-balance the requests.

Considering the current status of in-tree providers (see README), would you be interested to move this provider out of tree, using webhook ?

[Jeremy-Boyle]

@mloiseleur

Unfortunately, without going into any specifics, making it a webhook provider wouldn't work. No issues with that implementation, however our organization wouldn't be allowed or able to use anything other than the official images provided directly.

The loadblancer in front of the dns server is a valid option for some use cases. However we also use Kerberos, thus with a load balancer you would need to sticky session the entire session to the same server once it gets its session token which neglects the whole reason for this, and same with tsig.

This solution logs you into each host to properly handle sending requests to each individual server.

[k8s-ci-robot]

PR needs rebase.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes-sigs/prow repository.

[Jeremy-Boyle]

@mloiseleur , did you have any other questions or concerns before considering this pr?

[Jeremy-Boyle]

Can i please have a update for this please?