[stable/prometheus-operator] add udp protocol support for alertmanager NodePort service

[sev3ryn]

Is this a new chart

No

What this PR does / why we need it:

When joining alertmanager to external cluster it is required to have both UDP and TCP enabled for gossip to function properly.
See - https://github.com/prometheus/alertmanager#high-availability

Important: Both UDP and TCP are needed in alertmanager 0.15 and higher for the cluster to work.

Checklist

• DCO signed
• Chart Version bumped
• Title of the PR starts with chart name (e.g. [stable/mychartname])

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by: sev3ryn
To complete the pull request process, please assign vsliouniaev
You can assign the PR to them by writing /assign @vsliouniaev in a comment when ready.

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• stable/prometheus-operator/OWNERS

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[k8s-ci-robot]

Hi @sev3ryn. Thanks for your PR.

I'm waiting for a helm 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.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

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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/test-infra repository.

[sev3ryn]

/assign @vsliouniaev

[scottrigby]

/hold

Let’s hold PRs to prometheus-operator for a short time until prometheus-community/community#28 (comment) is resolved. If you want to help with that effort, to test etc, that would be great!

[scottrigby]

@sev3ryn as a user and contributor, would you mind helping to review/test this PR? prometheus-community/helm-charts#1

No need to reply here. If you can, please just reply and help there. It would help this process move along faster. Thanks!

[scottrigby]

🚧 This chart is now deprecated.

Further development has moved to prometheus-community/helm-charts. The chart has been renamed kube-prometheus-stack to more clearly reflect that it installs the kube-prometheus project stack, within which Prometheus Operator is only one component.

If applicable, please re-open this PR there. Thanks!