Bug 1793591

Summary:	use `ip=dhcp,dhcp6` by default on kernel command line
Product:	OpenShift Container Platform	Reporter:	Micah Abbott <miabbott>
Component:	RHCOS	Assignee:	Jonathan Lebon <jlebon>
Status:	CLOSED ERRATA	QA Contact:	Michael Nguyen <mnguyen>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	4.4	CC:	bbreard, dustymabe, imcleod, jerzhang, jligon, nstielau, smilner
Target Milestone:	---
Target Release:	4.4.0
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:	Previously, RHCOS defaulted to DHCPv4-only in the initramfs phase. Now, RHCOS tries both DHCPv4 and DHCPv6.	Story Points:	---
Clone Of:
Clones:	1793618 (view as bug list)		Environment:
Last Closed:	2020-05-04 11:25:48 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	1793618

Description Micah Abbott 2020-01-21 15:56:36 UTC

In order to properly support the IPv6 requirement in OCP 4.4, RHCOS needs to be able to perform DHCPv4 and DHCPv6 in the initramfs to bootstrap the nodes.

Part of this is achieved via a newer build of `dracut` from BZ#1787620, however we need to change the default kernel command line in RHCOS artifacts to use `ip=dhcp,dhcp6` as well.


This will likely require a change to `coreos-assembler`, for example:

https://github.com/coreos/coreos-assembler/blob/master/src/create_disk.sh#L366


And possibly `ignition-dracut`, for example:

https://github.com/coreos/ignition-dracut/blob/spec2x/grub/02_ignition_firstboot#L13

Comment 1 Micah Abbott 2020-01-21 16:17:23 UTC

This might be achieved with a change to the `image.yaml` file that is consumed by `coreos-assembler` for RHCOS and a patch to `ignition-dracut`

Comment 6 Micah Abbott 2020-01-30 15:32:43 UTC

The RHCOS image (44.81.202001241431.0) currently pinned to the installer has the modifed kernel cmdline.

Moving to MODIFIED

Comment 15 Micah Abbott 2020-02-13 20:44:59 UTC

Latest 4.4 nightly:

$ oc image info --output json $(oc adm release info -a ~/openshift-cluster-installs/all-the-pull-secrets.json --image-for=machine-os-content registry.svc.ci.openshift.org/ocp/release:4.4.0-0.nightly-2020-02-13-124128) | jq .config.config.Labels.version
"44.81.202002131031-0"

Booted QEMU image with `coreos-assembler run -d`, interrupted the boot to inspect boot menu:

$ coreos-assembler run -d rhcos-44.81.202002131031-0-qemu.x86_64.qcow2


load_video                                           
set gfxpayload=keep                                  
insmod gzio                                          
linux ($root)/ostree/rhcos-b3173727610b9b7a6404336ae7d850e0a1e22537ac141bf42ce\
81abac998c3a5/vmlinuz-4.18.0-147.5.1.el8_1.x86_64 rhcos.root=crypt_rootfs cons\
ole=tty0 console=ttyS0,115200n8 ignition.platform.id=qemu rd.luks.options=disc\
ard ignition.firstboot rd.neednet=1 ip=dhcp,dhcp6 ostree=/ostree/boot.1/rhcos/\
b3173727610b9b7a6404336ae7d850e0a1e22537ac141bf42ce81abac998c3a5/0             
initrd ($root)/ostree/rhcos-b3173727610b9b7a6404336ae7d850e0a1e22537ac141bf42c\
e81abac998c3a5/initramfs-4.18.0-147.5.1.el8_1.x86_64.img     


Marking VERIFIED with 44.81.202002131031-0

Comment 17 errata-xmlrpc 2020-05-04 11:25:48 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://access.redhat.com/errata/RHBA-2020:0581