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[DNM] OKD: Combined test of PR #7484 and PR #7634 #7641

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@JM1 JM1 commented Oct 27, 2023

TEST. DO NOT MERGE

Combined test of PR #7484 and PR #7634 for OKD/FCOS.

OCP requires DNS records api.<cluster_domain> and *.apps.\
<cluster_domain> to be externally resolvable (<cluster_domain> is
<cluster_name>.<base_domain>). For SNO this list also includes DNS
record api-int.<cluster_domain>.

However, OCP does not enforce ownership of all subdomains of
<cluster_domain>. For example, it is allowed to host a disconnected
image registry at <registry_hostname>.<cluster_domain> and OCP shall
be able to resolve it using the user-supplied external DNS resolver.

PR openshift#7516 changed the systemd-resolved config of the bootstrap node /
rendezvous host to associate the complete <cluster_domain> with the
DNS server at 127.0.0.1 where CoreDNS is supposed to be listening.

When a disconnected image registry is used for cluster installation,
the registry is hosted at <registry_hostname>.<cluster_domain> and
the bootstrap node / rendezvous host does not retrieve its domain
from the DHCP server, then the registry's DNS name cannot be
resolved.
That is because in order to pull the CoreDNS image, the disconnected
registry must be connected. The split dns mechanism of systemd-\
resolved would cause it to send DNS requests for
<registry_hostname>.<cluster_domain> to 127.0.0.1 where CoreDNS is
expected to be running which is not.

When a bootstrap node / rendezvous host retrieves its domain
<cluster_domain> from a DHCP server (e.g. dnsmasq's '--domain'
option) then systemd-resolved would associate <cluster_domain> not
only with 127.0.0.1 but also with the physical network interface,
causing DNS requests for <registry_hostname>.<cluster_domain> to be
send out to 127.0.0.1 as well as the external DNS resolver.

This patch mitigates the DNS issue for other network setups. It
changes the systemd-resolved config to forward DNS requests to
CoreDNS only for domains which are resolvable by CoreDNS:

* api.<cluster_domain>
* api-int.<cluster_domain>.
* apps.<cluster_domain>

DNS requests for <registry_hostname>.<cluster_domain> and other
subdomains of <cluster_domain> will be send out to the external
DNS resolver.

Fixes openshift#7516
…d Installer

OKD/FCOS uses FCOS as its bootimage, i.e. when booting cluster nodes
the first time during installation. FCOS does not provide tools such
as OpenShift Client (oc) or crio.service which Agent-based Installer
uses at the rendezvous host, e.g. to launch the bootstrap control
plane.

RHCOS and SCOS include these tools, but FCOS has to pivot the root fs
[1] to okd-machine-os [2] first in order to make those tools available.

Pivoting uses 'rpm-ostree rebase' but the rendezvous host is booted
the first time the node boots from a FCOS Live ISO where the root fs
and /sysroot are mounted read-only. Thus 'rpm-ostree rebase' fails and
necessary tools will not be available, causing the setup to stall.

Until rpm-ostree has implemented support for rebasing Live ISOs [3],
this patch adapts the workaround for SNO installations [4] to also
support Agent-based Installer.

In particular, the Go conditional {{- if .BootstrapInPlace }} which
is used to mark a SNO install has been replaced with a shell if-else
which checks at runtime whether the system is launched from are on a
Live ISO.
Most code in the OpenShift ecosystem is written with RHCOS in mind
and often assumes that tools like oc or crio.service are available.
These assumptions can be satisfied by applying this workaround to all
Live ISO boots. It will not remove functionality or overwrite
configuration files in /etc and thus side effects should be minimal.

The Go conditional {{- if .BootstrapInPlace }} in the release-image-\
pivot.service has been dropped completely. This service is only used
in OKD only, so OCP will not be impacted at all. The 'Before=' option
will not cause systemd to fail if a service does not exist. So, in
case bootkube.service or kubelet.service do not exist, the option will
have no effect.
When bootkube.service or kubelet.service do exist, it must always be
ensured that release-image-pivot.service is started first because it
might reboot the system or change /usr in the Live ISO use case.
So it is safe to drop the Go conditional and ask systemd to always
launch release-image-pivot.service before bootkube.service and
kubelet.service.

[0] https://github.com/openshift/installer/blob/master/data/data/bootstrap/files/usr/local/bin/bootkube.sh.template
[1] https://github.com/openshift/installer/blob/master/data/data/bootstrap/files/usr/local/bin/bootstrap-pivot.sh.template
[2] https://github.com/openshift/okd-machine-os
[3] coreos/rpm-ostree#4547
[4] openshift#7445
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JM1 commented Oct 27, 2023

/test okd-e2e-aws-ovn
/test okd-e2e-vsphere
/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6
/test okd-scos-e2e-aws-ovn
/test okd-scos-e2e-vsphere

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JM1 commented Oct 30, 2023

/test okd-e2e-aws-ovn
/test okd-e2e-vsphere
/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6
/test okd-scos-e2e-aws-ovn
/test okd-scos-e2e-vsphere

@andfasano
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/test okd-e2e-agent-compact-ipv4

(past job didn't get a resource from ofcir)

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JM1 commented Oct 30, 2023

(need release image to test)

/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6

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JM1 commented Oct 30, 2023

(need release image to test again)

/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6

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JM1 commented Oct 30, 2023

/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6

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JM1 commented Nov 1, 2023

/test okd-e2e-aws-ovn
/test okd-e2e-vsphere
/test okd-e2e-agent-compact-ipv4
/test okd-e2e-agent-sno-ipv6
/test okd-scos-e2e-aws-ovn
/test okd-scos-e2e-vsphere

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JM1 commented Nov 1, 2023

/test okd-e2e-agent-compact-ipv4

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JM1 commented Nov 1, 2023

/test okd-e2e-agent-compact-ipv4

@andfasano
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/test okd-e2e-agent-compact-ipv4

@andfasano
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Let's try also ha flavor:

/test okd-e2e-agent-ha-dualstack

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/test okd-e2e-agent-ha-dualstack

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/test okd-e2e-agent-compact-ipv4

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@andfasano
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/test okd-e2e-agent-compact-ipv4

@andfasano
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/test okd-e2e-agent-compact-ipv4

@andfasano
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Latest agent compact failures was due etcd operator being degraded, not sure it's related to the current patch

/test okd-e2e-agent-compact-ipv4

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All the okd agent jobs are green

/approve

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openshift-ci bot commented Nov 6, 2023

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andfasano

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@openshift-ci openshift-ci bot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Nov 6, 2023
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openshift-ci bot commented Nov 10, 2023

@JM1: The following tests failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name Commit Details Required Rerun command
ci/prow/e2e-metal-single-node-live-iso f8d29c5 link false /test e2e-metal-single-node-live-iso
ci/prow/e2e-metal-ipi-sdn-virtualmedia f8d29c5 link false /test e2e-metal-ipi-sdn-virtualmedia
ci/prow/e2e-metal-assisted f8d29c5 link false /test e2e-metal-assisted
ci/prow/okd-e2e-vsphere f8d29c5 link false /test okd-e2e-vsphere
ci/prow/okd-scos-e2e-vsphere f8d29c5 link false /test okd-scos-e2e-vsphere
ci/prow/altinfra-e2e-aws-ovn-upi f8d29c5 link true /test altinfra-e2e-aws-ovn-upi

Full PR test history. Your PR dashboard.

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JM1 commented Nov 16, 2023

Code works as expected. Closing PR and continuing in original PRs.

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