Paul Bastide

Blog

  • Red Hat OpenShift Container Platform on IBM Power Systems: Exploring Red Hat’s Multi-Arch Tuning Operator

    The Red Hat Multi-Arch Tuning Operator optimizes workload placement within multi-architecture compute clusters. Pods run on the compute architecture for which the containers declare support. Where Operators, Deployments, ReplicaSets, Jobs, CronJob, Pods don’t declare a nodeAffinity, in most cases, the Pods that are generate are updated with the node affinity so it lands on the supported (declared) CPU Architecture.

    For version 1.1.0, the Red Hat Multi-Arch Team, @Prashanth684, @aleskandro, @AnnaZivkovic and IBM Power Systems team @pkenchap have worked together to give cluster administrators better control and flexibility. The feature adds a plugins field in ClusterPodPlacementConfig and have build a first plugin called nodeAffinityScoring.

    Per the docs, the nodeAffinityScoring plugin adds weights and influence to the scheduler with this process:

    1. Analyzing the Pod’s containers for the supported architectures
    2. Generate the Scheduling predicates for nodeAffinity, e.g., 75 weight on ppc64le
    3. Filter out nodes that do not meet the Pod requirements, using the Predicates
    4. Prioritizes the remaining nodes based on the architecture scores defined in the nodeAffinityScoring.platforms field.

    To take advantages of this feature, use the following to asymmetrically load the Power nodes with work.

    apiVersion: multiarch.openshift.io/v1beta1
kind: ClusterPodPlacementConfig
metadata:
  name: cluster
spec:
  logVerbosityLevel: Normal
  namespaceSelector:
    matchExpressions:
      - key: multiarch.openshift.io/exclude-pod-placement
        operator: Exists
  plugins:
    nodeAffinityScoring:
      enabled: true
      platforms:
        - architecture: ppc64le
          weight: 100
        - architecture: amd64
          weight: 50

    Best wishes, and looking forward to hearing how you use the Multi-Arch Tuning Operator on IBM Power with Multi-Arch Compute.

    References

    1. [RHOCP][TE] Multi-arch Tuning Operator: Cluster-wide architecture preferred/weighted affinity
    2. OpenShift 4.18 Docs: Chapter 4. Configuring multi-architecture compute machines on an OpenShift cluster
    3. OpenShift 4.18 Docs: 4.11. Managing workloads on multi-architecture clusters by using the Multiarch Tuning Operator
    4. Enhancement: Introducing the namespace-scoped PodPlacementConfig

  • nx-gzip requires active_mem_expansion_capable

    nx-gzip requires the licensed process caability active_mem_expansion_capable

    Login to your HMC

    for MACHINE in my-ranier1 my-ranier2
do
echo "MACHINE: ${MACHINE}"
for CAPABILITY in $(lssyscfg -r sys -F capabilities -m "${MACHINE}" | sed 's|,| |g' | sed 's|"||g')
do
echo "CAPABILITY: ${CAPABILITY}" | grep active_mem_expansion_capable
done
echo
done

    The following shows:

    MACHINE: my-ranier1
CAPABILITY: active_mem_expansion_capable
CAPABILITY: hardware_active_mem_expansion_capable
CAPABILITY: active_mem_mirroring_hypervisor_capable
CAPABILITY: cod_mem_capable
CAPABILITY: huge_page_mem_capable
CAPABILITY: persistent_mem_capable

MACHINE: my-ranier2
CAPABILITY: cod_mem_capable
CAPABILITY: huge_page_mem_capable
CAPABILITY: persistent_mem_capable

    Then you should be all set to use nx-gzip on my-ranier1

    Best wishes

  • Setting up nx-gzip in a non-privileged container

    In order to use nx-gzip on Power Systems with a non-privileged container, use the following recipe:

    On each of the nodes, create the selinux power-nx-gzip.cil:

    (block nx
    (blockinherit container)
    (allow process container_file_t ( chr_file ( map )))
)

    Install the CIL on each worker node

    sudo semodule -i power-nx-gzip.cil /usr/share/udica/templates/base_container.cil

    I ran the following:

    podman run -it --security-opt label=type:nx.process --device=/dev/crypto/nx-gzip registry.access.redhat.com/ubi9/ubi@sha256:a1804302f6f53e04cc1c6b20bc2204d5c9ae6e5a664174b38fbeeb30f7983d4e sh

    I copied the files into the container using the container CONTAINER ID:

    podman ps
podman cp temp 6a4d967f3b6b:/tmp
podman cp gzfht_test 6a4d967f3b6b:/tmp

    Then running in the container:

    sh-5.1# cd /tmp
sh-5.1# ./gzfht_test temp
file temp read, 1048576 bytes
compressed 1048576 to 1105922 bytes total, crc32 checksum = 3c56f054

    You can use ausearch -m avc -ts recent | audit2allow to track down missing permissions

    Hope this helps you…

    Reference

    https://github.com/libnxz/power-gzip

  • Helpful Tool – mtr

    I was not aware of the mtr which Network diagnostic tool combining 'traceroute' and 'ping'.

    You can quickly install on RHEL/Centos with sudo dnf install -y mtr

    The output is super helpful to where you have drops:

     mtr --report bastide.org
Start: 2025-04-04T12:44:43-0400
HOST: nx-gzip-d557-bastion-0.x Loss%   Snt   Last   Avg  Best  Wrst StDev
  1.|-- 10.20.176.3                0.0%    10    1.9   1.2   0.9   1.9   0.3
  2.|-- 172.16.32.4                0.0%    10    0.7   0.7   0.7   0.8   0.0
  3.|-- att-vc-srx-interconnect.p  0.0%    10   30.2  33.9  25.4  62.6  11.0
  4.|-- XX.5.16.XXX                0.0%    10   11.8  11.8  11.7  12.0   0.1
  5.|-- po97.prv-leaf6a.net.unifi  0.0%    10   62.5  63.2  62.5  67.5   1.5

  • DNS Resolver Hangs with OpenVPN

    Running multiple OpenVPN on the mac, sometimes my DNS hangs and I can’t get the VPNs. I use this hack to get around it.

    ❯ sudo networksetup -setdnsservers Wi-Fi "Empty"

  • Help… My Ingress is telling me OAuthServerRouteEndpointAccessibleControllerDegraded

    My teammate hit an issue with Ingress Certificates not being valid:

    oc get co ingress -oyaml
    message: |-
      OAuthServerRouteEndpointAccessibleControllerDegraded: Get "https://oauth-openshift.apps.mycluster.local/healthz": tls: failed to verify certificate: x509: certificate has expired or is not yet valid: current time 2025-04-02T17:58:35Z is after 2025-02-13T20:04:16Z
      RouterCertsDegraded: secret/v4-0-config-system-router-certs.spec.data[apps.mycluster.local] -n openshift-authentication: certificate could not validate route hostname oauth-openshift.apps.mycluster.local: x509: certificate has expired or is not yet valid: current time 2025-04-02T17:58:33Z is after 2025-02-13T20:04:16Z

    The Red Hat docs and tech articles are great. I found How to redeploy/renew an expired default ingress certificate in RHOCP4?

    I ran the following on a non-production cluster:

    1. Renewed the ingress CA:
    oc get secret router-ca -oyaml -n openshift-ingress-operator> router-ca-2025-04-02.yaml
oc delete secret router-ca -n openshift-ingress-operator
oc delete pod --all -n openshift-ingress-operator
wait 30
oc get secret router-ca -n openshift-ingress-operator
oc get po -n openshift-ingress-operator
    1. Recreate the wild-card ingress certificate using the new ingress CA:
    oc get secret router-certs-default -o yaml -n openshift-ingress > router-certs-default-2025-04-02.yaml
oc delete secret router-certs-default -n openshift-ingress 
oc delete pod --all -n openshift-ingress 
wait 30
oc get secret router-certs-default -n openshift-ingress 
oc get po -n openshift-ingress
    1. Checked the ingress
    curl -v https://oauth-openshift.apps.mycluster.local/healthz -k
*  subject: CN=*.apps.mycluster.local
*  start date: Apr  2 19:08:33 2025 GMT
*  expire date: Apr  2 19:08:34 2027 GMT
    1. Update ca-trust
    oc -n openshift-ingress-operator get secret router-ca -o jsonpath="{ .data.tls\.crt }" | base64 -d -i > ingress-ca-2025-04-02.crt
cp /root/ingress-ca-2025-04-02.crt /etc/pki/ca-trust/source/anchors/
update-ca-trust
    1. Login now works
    oc login -u kubeadmin -p YOUR_PASSWORD https://api.mycluster.local:6443

    You’ve seen how to recreate the cert.

    You should use the cert-manager operator from Red Hat.

  • Multi-Arch Tuning Operator 1.1.0 Released

    The Red Hat team has released a new version of the Multi-Arch Tuning Operator.

    In Multi-Arch Compute clusters, the Multiarch Tuning Operator influences the scheduling of Pods, so application run on the supported architecture.

    You can learn more about it at https://catalog.redhat.com/software/containers/multiarch-tuning/multiarch-tuning-operator-bundle/661659e9c5bced223a7f7244

    Addendum

    My colleague, Punith, worked with the Red Hat team to add NodeAffinityScoring and plugin support to the Multi-Arch Tuning Operator and ClusterPodPlacementConfig. This feature allows users to define cluster-wide preferences for specific architectures, influencing how the Kubernetes scheduler places pods. It helps optimize workload distribution based on preferred node architecture.

    	Spec:
	    Plugins:
		NodeAffinityScoring:
		   enabled: true
		   platforms:
		   - architecture: ppc64le
		     weight: 100
		   - architecture: amd64
		     weight: 50

  • FIPS support in Go 1.24

    Kudos to the Red Hat team. link

    The benefits of native FIPS support in Go 1.24

    The introduction of the FIPS Cryptographic Module in Go 1.24 marks a watershed moment for the language’s security capabilities. This new module provides FIPS 140-3-compliant implementations of cryptographic algorithms, seamlessly integrated into the standard library. What makes this particularly noteworthy is its transparent implementation. Existing Go applications can leverage FIPS-compliant cryptography without requiring code changes.

    Build-time configuration through the GOFIPS140 environment variable, allowing developers to select specific versions of the Go Cryptographic Module.

    GOFIPS140=true go build

    Runtime control via the fips140 GODEBUG setting, enabling dynamic FIPS mode activation.

    GODEBUG=

    Keep these in your toolbox along with GOARCH=ppc64le

  • Updates to Open Source Container images for Power on IBM Container Registry

    The IBM Linux on Power team pushed new images to their public open source container images in the IBM Container Registry (ICR). This should assure end users that IBM has authentically built these containers in a secure environment.

    The new container images are:

    Image NameTag NameProject LicensesImage Pull CommandLast Published
    fluentd-kubernetes-daemonsetv1.14.3-debian-forward-1.0Apache-2.0podman pull icr.io/ppc64le-oss/fluentd-kubernetes-daemonset:v1.14.3-debian-forward-1.0March 17, 2025
    cloudnative-pg/pgbouncer1.23.0Apache-2.0podman pull icr.io/ppc64le-oss/cloudnative-pg/pgbouncer:1.23.0March 17, 2025

  • Red Hat OpenShift Container Platform 4.18 Now Available on IBM Power

    Red Hat OpenShift 4.18 Now Available on IBM Power Red Hat® OpenShift® 4.18 has been released and adds improvements and new capabilities to OpenShift Container Platform components. Based on Kubernetes 1.31 and CRI-O 1.31, Red Hat OpenShift 4.18 focused on core improvements with enhanced network flexibility.

    You can download 4.18.1 from the mirror at https://mirror.openshift.com/pub/openshift-v4/multi/clients/ocp/4.18.1/ppc64le/