Cloud-init causes potentially huge boot delays with 4.15 kernels

[Kimball Johnson]

portion of bug report for bionic:

Newer 4.15 kernels contain the following fix for CVE-2018-1108:
  43838a23a05fb ("random: fix crng_ready() test")

This causes cloud-init to stall for a potentially long time during boot (waiting for entropy I presume). Google reported boot delays of 75 minutes.

I've tracked this down to the following import in templater.py which causes the delay:
    from jinja2 import Template as JTemplate

Which is called when cc_update_etc_hosts is imported.

NOTE: I'm experiencing this with focal repeatedly - just hangs forever!

ubunutu 20.04 server - live

[Ubuntu Kernel Bot (ubuntu-kernel-bot)]

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1880334

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

[Dan Watkins (oddbloke)]

Hi Kimball,

Thanks for the bug report! We need more information to be able to triage it further. Could you please run `cloud-init collect-logs` on an affected instance and attach the tarball it produces to this bug? (Once done, please move the cloud-init task back to New and we'll take a look. :)

Thanks!

Dan

[Juerg Haefliger (juergh)]

Is this a bug against the Focal 5.4 kernel or Bionic 4.15 or both? Could you please adjust the bug title accordingly?

[Ee (e2tha-e)]

I'm pretty sure this is for the 5.4 kernel. Also, I resolved the entropy issue by installing haveged https://packages.ubuntu.com/focal/misc/haveged

Can anyone else verify if this works?

[Launchpad Janitor (janitor)]

[Expired for cloud-init (Ubuntu) because there has been no activity for 60 days.]

[Launchpad Janitor (janitor)]

[Expired for linux (Ubuntu) because there has been no activity for 60 days.]