Flatcar optimize network configuration speed on vmware cloud director

[4ch3los]

Dont wait for network when using flatcar on vmware-cloud-director, as bootstrap script configures network. To achieve this, template support for unit files was added. This reduces bootstrapping time alot, as waiting for network times out currently

What this PR does / why we need it:

Which issue(s) this PR fixes:

What type of PR is this?
/kind bug

Special notes for your reviewer:

Does this PR introduce a user-facing change? Then add your Release Note here:

Flatcar Vmware cloud director, bootstrap time improved

Documentation:

NONE

[kubermatic-bot]

Hi @4ch3los. Thanks for your PR.

I'm waiting for a kubermatic 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.

I understand the commands that are listed here.

Details

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.

[kubermatic-bot]

Issues go stale after 90d of inactivity.
After a furter 30 days, they will turn rotten.
Mark the issue as fresh with /remove-lifecycle stale.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[kron4eg]

is this about rendering the whole provision config and sending it as a userdata so that VM can be provisioned right away without fetching its provisioning instructions?

[4ch3los]

is this about rendering the whole provision config and sending it as a userdata so that VM can be provisioned right away without fetching its provisioning instructions?

Ahh no, the provisioning process doesnt get changed, but for flatcar on vcloud director, the network gets configured by the bootstrap service/script https://github.com/kubermatic/operating-system-manager/blob/main/deploy/osps/default/osp-flatcar.yaml#L192
But the service units is defined to run after the network is available, which wont happen before it runs, so it waits for the timeout and delays the provisioning by about 2 minutes. This pr adds the ability to template the units with go templating, and removes the wait on the bootstrap.unit for flatcar on vcloud :)

[kron4eg]

/ok-to-test

[kubermatic-bot]

Issues go stale after 90d of inactivity.
After a furter 30 days, they will turn rotten.
Mark the issue as fresh with /remove-lifecycle stale.

If this issue is safe to close now please do so with /close.

/lifecycle stale

[kron4eg]

/ok-to-test
/cc

[kron4eg]

/cc @ahmedwaleedmalik

@ahmedwaleedmalik Can you please provide the original idea why units was not been rendered in the first place?

@4ch3los did you considered using systemd units drop-ins in order to customize that unit? An example would be a file (which is already rendered) in the specific directory.

[ahmedwaleedmalik]

While i'm not against the idea per say but this is a bit of a scope creep if we add template rendering for units just for this one use case. The reason we didn't templatize them was that most, if not all, customizations can be done using drop-ins and there wasn't a use case for this.

Like @kron4eg suggested, we can simply have a drop-in like:

  - path: /etc/systemd/system/bootstrap.service.d/10-no-network-wait.conf              
    content:                                                                           
      inline:                                                                          
        data: |                                                                        
          {{- if eq .CloudProviderName "vmware-cloud-director" }}                      
          [Unit]                                                                       
          Requires=                                                                    
          After=                                                                       
          {{- end }}  

[4ch3los]

Totally fair and way easier :) im going to redo the pr

[kron4eg]

how to fix the CI

[4ch3los]

@kron4eg hopefully the ci should succeed now, but during testing i discovered that dropins cant clear Requires, so i inverted the behaviour to add the Requires as Dropin, for non vcloud platform

[ahmedwaleedmalik]

/approve

[kubermatic-bot]

LGTM label has been added.

Details

Git tree hash: d3f651f97ced6ff4d6b84a38189c3d77f864e39c

[ahmedwaleedmalik]

/approve

[kubermatic-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: ahmedwaleedmalik

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Details

Needs approval from an approver in each of these files:

• OWNERS [ahmedwaleedmalik]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment