[prometheus-node-exporter] Add rootfs mount by default

[ghost]

Signed-off-by: Dan Jones [email protected]

@gianrubio
@vsliouniaev

What this PR does / why we need it:

Adds rootfs mount by default, resolving an issue where root filesystem metrics are incorrectly reported if the container runtime storage is not on the host root filesystem.

Which issue this PR fixes

issue from old repo: helm/charts#22905

Special notes for your reviewer:

Checklist

• DCO signed
• Chart Version bumped
• Title of the PR starts with chart name (e.g. [prometheus-couchdb-exporter])

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Any further update will cause the issue/pull request to no longer be considered stale. Thank you for your contributions.

[monotek]

Not stale.

@gianrubio @vsliouniaev
Please review.

[monotek]

I'm not sure if this should be optional.

@gianrubio @vsliouniaev
Thoughts?

[vsliouniaev]

Looks good to me, were running the same configuration. I would argue that not having this configuration is quite limiting, since you aren't accessing the host volume information

[xxbbxb]

Hi everybody, I have an issue with this patch: docker is unable to mount / with error:

failed to start container "node-exporter": Error response from daemon: path / is mounted on / but it is not a shared or slave mount

We need either remove mountPropagation option or make root shared among namespaces mount --make-shared /
corresponding kubernetes issue kubernetes/kubernetes#61058 (comment)

[monotek]

Please create a new issue using the issue template so we have all info about your environment.