rpk: supports triggering on-demand balancer

[daisukebe]

Although the continuous balancer has been becoming smart, there's still needs where we need to invoke the on-demand balancer to balance partitions across brokers. This commit adds a new rpk cluster partitions balance command that wraps the POST /v1/partitions/rebalance endpoint.

Internal discussion: https://redpandadata.slack.com/archives/C04LYNJQUGN/p1722580784813209

Backports Required

• none - not a bug fix
• none - this is a backport
• none - issue does not exist in previous branches
• none - papercut/not impactful enough to backport
• v24.2.x
• v24.1.x
• v23.3.x

Release Notes

Features

• rpk: supports triggering on-demand partition balancer

[daisukebe]

I should have updated rpadmin first. Tagged v0.1.4 https://github.com/redpanda-data/common-go/tree/rpadmin/v0.1.4/rpadmin, but it's not in the main branch. Created redpanda-data/common-go#12 there.

[r-vasquez]

@daisukebe Can you please delete and recreate the tag from main once redpanda-data/common-go#12 is merged?

[daisukebe]

Force pushed: 72ee8ca

• Updated to https://github.com/redpanda-data/common-go/tree/rpadmin/v0.1.4
• Added some detailed information in the long help text

[vbotbuildovich]

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/52920#019151c9-88c8-4d35-923b-dc4aed2aa181

ducktape was retried in https://buildkite.com/redpanda/redpanda/builds/53021#01915927-bca7-48c0-94ec-96f34a4503a6

[r-vasquez]

Code LGTM, thanks!

[daisukebe]

Force pushed: 8164de9

• Applied Joyce's suggestion on the help text
• Fixed the typo
• Removed the formatter

[Deflaimun]

lgtm from docs

[daisukebe]

Force pushed again (sorry) to align with wording; balancer -> balancing.

[r-vasquez]

LGTM, thanks!

[vbotbuildovich]

/backport v24.2.x

[vbotbuildovich]

/backport v24.1.x

[vbotbuildovich]

Failed to create a backport PR to v24.2.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-22855-v24.2.x-250 remotes/upstream/v24.2.x
git cherry-pick -x 62031165e3c6867939e182a4066bf6831088248a

Workflow run logs.

[vbotbuildovich]

Failed to create a backport PR to v24.1.x branch. I tried:

git remote add upstream https://github.com/redpanda-data/redpanda.git
git fetch --all
git checkout -b backport-pr-22855-v24.1.x-736 remotes/upstream/v24.1.x
git cherry-pick -x 62031165e3c6867939e182a4066bf6831088248a

Workflow run logs.