[Fleet] Display k8 daemonset yaml in standalone mode

[mukeshelastic]

In the add agent flyout, if a K8s integration is detected then the standalone mode policy should be the K8s daemonset manifest and not general agent policy and the instructions to install agent should be the kubelet apply -f filename.yaml and not ./elastic-agent install.

[elasticmachine]

Pinging @elastic/fleet (Feature:Fleet)

[mukeshelastic]

@ChrsMark fyi

[jen-huang]

@mukeshelastic Does this differ from #92113?

[mukeshelastic]

It does differ but just by a little bit.

This issue relates to add-agent flyout->standalone tab to show K8s daemonset yaml as opposed to the usual agent policy yaml.

#92113 is about fleet mode to show K8s as a platform in the dropdown, for agent policies with K8s integration, making K8s platform as a default choice, including the fleet enrollment token in the daemonset yaml and then install command to be kubectl apply -f daemonset_config.yaml and option to download that file..

There is definitely different work involved in these two issues hence I created them separately but may make sense to do it together to get it all done with single attempt.

[david-kow]

Should we also be providing ECK Agent resource manifest to achieve the same?

[ChrsMark]

Should we also be providing ECK Agent resource manifest to achieve the same?

It could be an option. We could have 3 tabs like standalone|kubernetes raw|kubernetes eck. I'm not quite sure how easy it would be to combine upstream's manifests and fleet's policies but this should be the way to go so as to be in sync with the source of k8s manifests we maintain. @david-kow do you have any similar upstream files for eck managed Agent?

[david-kow]

I do like the idea of including ECK as an option there.

We maintain (ie. test them as part of our E2E tests) a number of recipes. They are also exposed in our docs for standalone and fleet modes.