Current Status: Experimental
This document discusses the installer support for an IPI (Installer Provisioned Infrastructure) install for bare metal hosts. This includes platform support for the management of bare metal hosts, as well as some automation of DNS and load balancing to bring up the cluster.
The upstream project that provides Kubernetes-native management of bare metal hosts is metal3.io.
For UPI (User Provisioned Infrastructure) based instructions for bare metal deployments, see install_upi.md.
It is assumed that all hosts have at least 2 NICs, used for the following purposes:
-
NIC #1 - External Network
- This network is the main network used by the cluster, including API traffic and application traffic.
- DHCP
- External DHCP is assumed on this network. It is strongly recommended to set up DHCP reservations for each of the hosts in the cluster to ensure that they retain stable IP addresses.
- A pool of dynamic addresses should also be available on this network, as the provisioning host and temporary bootstrap VM will also need addresses on this network.
- NTP
- A time source must be accessible from this network.
- Reserved VIPs (Virtual IPs) - 3 IP addresses must be reserved on this
network for use by the cluster. Specifically, these IPs will serve the
following purposes:
- API - This IP will be used to reach the cluster API.
- Ingress - This IP will be used by cluster ingress traffic
- DNS - This IP will be used internally by the cluster for automating internal DNS requirements.
- External DNS - While the cluster automates the internal DNS
requirements, two external DNS records must be created in whatever DNS
server is appropriate for this environment.
api.<cluster-name>.<base-domain>
- pointing to the API VIP*.apps.<cluster-name>.<base-domain>
- pointing to the Ingress VIP
-
NIC #2 - Provisioning Network
- A private network used for PXE based provisioning.
- DHCP is automated for this network by default, to rely on external
DHCP, set the platform's
provisioningDHCPExternal
option totrue
- Addressing for this network defaults to
172.22.0.0/24
, but is configurable by setting theprovisioningNetworkCIDR
option. - Two IP's are required to be available for use, one for the bootstrap
host, and one as a provisioning IP in the running cluster. By
default, these are the 2nd and 3rd addresses in the
provisioningNetworkCIDR
(e.g. 172.22.0.2, and 172.22.0.3). - To specify the name of the provisioning network interface,
set the
provisioningNetworkInterface
option. This is the network interface on a master that is connected to the provisioning network.
-
Out-of-band Management Network
- Servers will typically have an additional NIC used by the onboard management controllers (BMCs). These BMCs must be accessible and routed to the host.
The installer must be run from a host that is attached to the same networks as the cluster, as described in the previous section. We refer to this host as the provisioning host. The easiest way to provide a provisioning host is to use one of the hosts that is intended to later become a worker node in the same cluster. That way it is already connected to the proper networks.
It is recommended that the provisioning host be a bare metal host, as it must be able to use libvirt to launch the OpenShift bootstrap VM locally.
The architecture is intended to support a wide variety of hardware. This was one of the reasons Ironic is used as an underlying technology. However, so far development and testing has focused on PXE based provisioning using IPMI for out-of-band management of hosts. Other provisioning approaches will be added, tested, and documented over time.
Once an environment has been prepared according to the documented pre-requisites, the install process is the same as other IPI based platforms.
openshift-install create cluster
However, it is recommended to prepare an install-config.yaml
file in advance,
containing all of the details of the bare metal hosts to be provisioned.
The install-config.yaml
file requires some additional details. Most of the
information is teaching the installer and the resulting cluster enough about
the available hardware so that it is able to fully manage it.
Here is an example install-config.yaml
with the required baremetal
platform
details.
IMPORTANT NOTE: The current install configuration for the baremetal
platform should be considered experimental and still subject to change without
backwards compatibility. In particular, some items likely to change soon
include:
- The
hardwareProfile
is currently exposed as a way to allow specifying different hardware parameters for deployment. By default, we will deploy RHCOS to the first disk, but that may not be appropriate for all hardware. ThehardwareProfile
is the field we have available to change that. This interface is subject to change. In the meantime, hardware profiles can be found here: https://github.com/metal3-io/baremetal-operator/blob/master/pkg/hardware/profile.go#L48
apiVersion: v1
baseDomain: test.metalkube.org
metadata:
name: ostest
networking:
machineNetwork:
- cidr: 192.168.111.0/24
compute:
- name: worker
replicas: 1
controlPlane:
name: master
replicas: 3
platform:
baremetal: {}
platform:
baremetal:
apiVIP: 192.168.111.5
ingressVIP: 192.168.111.4
dnsVIP: 192.168.111.3
hosts:
- name: openshift-master-0
role: master
bmc:
address: ipmi://192.168.111.1:6230
username: admin
password: password
bootMACAddress: 00:11:07:4e:f6:68
hardwareProfile: default
- name: openshift-master-1
role: master
bmc:
address: ipmi://192.168.111.1:6231
username: admin
password: password
bootMACAddress: 00:11:07:4e:f6:6c
hardwareProfile: default
- name: openshift-master-2
role: master
bmc:
address: ipmi://192.168.111.1:6232
username: admin
password: password
bootMACAddress: 00:11:07:4e:f6:70
hardwareProfile: default
- name: openshift-worker-0
role: worker
bmc:
address: ipmi://192.168.111.1:6233
username: admin
password: password
bootMACAddress: 00:11:07:4e:f6:71
hardwareProfile: default
pullSecret: ...
sshKey: ...
Integration of the baremetal
platform is still a work-in-progress across
various parts of OpenShift. This section discusses key items that are not yet
fully integrated, and their workarounds.
Note that once this work moves into the openshift/installer
repository, new
issues will get created or existing issues will be moved to track these gaps
instead of the leaving the existing issues against the KNI fork of the installer.
openshift-install destroy cluster
is not supported for the baremetal
platform.
openshift-metal3/kni-installer#74
When an installation fails, openshift-install
will attempt to gather debug
information from hosts. This is not yet supported by the baremetal
platform.
openshift-metal3/kni-installer#79
There are some install-config parameters to control templating of the provisioning network configuration, but fully supporting alternative subnets for the provisioning network is incomplete.
General troubleshooting for OpenShift installations can be found here.
The bootstrap VM by default runs on the same host as the installer. This bootstrap VM runs the Ironic services needed to provision the control plane. Ironic being available is dependent on having successfully downloaded the machine OS and Ironic agent images. In some cases, this may fail, and the installer will report a timeout waiting for the Ironic API.
To login to the bootstrap VM, you will need to ssh to the VM using the
core
user, and the SSH key defined in your install config.
The VM obtains an IP address from your DHCP server on the external
network. When using a development environment with
dev-scripts, it uses
the baremetal
libvirt network unless an override is specified. The IP
can be retrieved with virsh net-dhcp-leases baremetal
. If the install
is far enough along to have brought up the provisioning network, you may
use the provisioning bootstrap IP which defaults to 172.22.0.2.
Viewing the virtual machine's console with virt-manager may also be helpful.
You can view the Ironic logs by sshing to the bootstrap VM, and
examining the logs of the ironic
service, journalctl -u ironic
. You
may also view the logs of the individual containers:
podman logs ipa-downloader
podman logs coreos-downloader
podman logs ironic
podman logs ironic-inspector
podman logs ironic-dnsmasq
Once Ironic is available, the installer will provision the three control plane hosts. For early failures, it may be useful to look at the console (using virt-manager if emulating baremetal with vbmc, or through the BMC like iDRAC) and see if there are any errors reported.
Additionally, if the cluster comes up enough that the bootstrap is destroyed,
but commands like oc get clusteroperators
shows degraded operators, it
may be useful to examine the logs of the pods within the
openshift-kni-infra
namespace.
You may want to examine Ironic itself and look at the state of the hosts. The below file, when named clouds.yaml and placed in the current working directory, can be used to communicate with Ironic using the openstack commandline utilities.
clouds:
metal3-bootstrap:
auth_type: none
baremetal_endpoint_override: http://172.22.0.2:6385
baremetal_introspection_endpoint_override: http://172.22.0.2:5050
metal3:
auth_type: none
baremetal_endpoint_override: http://172.22.0.3:6385
baremetal_introspection_endpoint_override: http://172.22.0.3:5050
If bootstrap is still up, you can use metal3-bootstrap, otherwise use metal3 to examine Ironic running in the control plane:
export OS_CLOUD=metal3-bootstrap
/usr/local/bin/openstack baremetal node list