Files
bluejay-infra/apps/multus/multus.yaml
Codex eb8693e1ce fix(multus): bump kube-multus-ds memory 50Mi/50Mi -> 1Gi/512Mi (prevent OOM cascade)
Cluster outage 2026-05-10T17:43 through 2026-05-11 ~10:30 (~21h). Root cause:
FlowerCore.RemoteDesktop emitted 219 orphan rd-browser-only-* pods in fc-desktop
(missing OwnerReferences — see companion fix in FlowerCore.RemoteDesktop).
Kubelet's continuous CNI ADD retries for those pending pods drove a request
queue that exceeded the upstream default 50Mi limit on kube-multus-ds. Multus
OOMKilled (exit 137), restarted with an even bigger backlog, OOMKilled again,
positive feedback loop. Restart counts climbed to 276 / 412 / 261 across the
3 RKE2 nodes.

Downstream blast radius: both Traefik pods stuck ContainerCreating (101m +
4h35m), all Longhorn CSI attacher/provisioner/instance-manager stuck, every
Prometheus blackbox probe for *.iamworkin.lan failing, UpdateCenterPublicEdgeDown
critical on update.flowercore.io, every ArgoCD app showing sync=Unknown
because repo-server lost git connectivity. 45 firing Prometheus alerts.

Recovery sequence (Q-MR-1 from FlowerCore.Notes morning routine):
1. kubectl patch kube-multus-ds memory live (this commit locks it in git so
   ArgoCD doesn't revert on next sync)
2. Force-delete the 219 orphan pods (kubectl --grace-period=0 --force) to
   break the avalanche
3. Rollout restart kube-multus-ds — STABLE after restart with new limit
4. Restart Traefik + Longhorn CSI to clear stuck ContainerCreating
5. Verify update.flowercore.io returns 200 + ArgoCD apps reconcile

Tested incrementally: 256Mi limit was insufficient (still OOMed on catchup
burst), 512Mi was insufficient on rke2-agent1 (most pods concentrated there),
1Gi/512Mi handled the full 200+ pending pod CNI catchup cleanly with 0 multus
restarts after rollout. Nodes are 64GB with <25% used in steady-state, so the
~256Mi typical working-set is well within the new limit.

Companion change: FlowerCore.RemoteDesktop must set OwnerReferences on every
worker pod so future operator crashes don't leak orphans (Q-MR-2). Preventive
alerts (Q-MR-3) MultusMemoryPressure + NamespacePendingPodBacklog are coming
in a follow-up commit to apps/monitoring/.

Memory: feedback_multus_50mi_limit_oom_orphan_pod_avalanche
Decisions card: docs/dashboards/decisions-waiting.html Q-MR-1..3

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-11 10:30:05 -05:00

298 lines
9.9 KiB
YAML

# =============================================================================
# Multus CNI — Meta-CNI for multi-network attachment to pods/VMs
# =============================================================================
# Purpose: enable KubeVirt VMs (and any future workload) to attach additional
# network interfaces beyond the default Calico-managed pod network. Required
# for ci1 (Windows Server 2025 KubeVirt VM) to bridge onto PROD VLAN 57.
#
# Source: upstream k8snetworkplumbingwg/multus-cni v4.2.2
# https://github.com/k8snetworkplumbingwg/multus-cni/blob/v4.2.2/deployments/multus-daemonset-thick.yml
#
# Inlined verbatim (with project header + version pin annotation) for
# reproducibility and air-gap safety. Bumping versions = edit this file +
# git push. ArgoCD picks up via the bluejay-infra ApplicationSet
# (apps/* directory generator on main).
#
# Why thick plugin (not thin):
# - Thick = daemon + thin shim binary; daemon handles NAD watch + CRD reads
# centrally so each pod's CNI ADD doesn't hit the K8s API server. Better
# for clusters with many NAD-using pods.
# - Thin = each CNI ADD process directly contacts K8s API. Simpler but
# scales worse and has more failure modes.
# - KubeVirt + multi-VM workload pattern fits thick perfectly.
#
# Cluster context (verified 2026-05-08):
# - RKE2 v1.34.5 on 3 nodes (rke2-server, rke2-agent1, rke2-agent2)
# - Calico CNI (Tigera-managed) at /etc/cni/net.d + /opt/cni/bin (default)
# - openSUSE Leap 16, kernel 6.12, containerd 2.1.5
# - host bridge for PROD VLAN 57 = `br-prod` (PUPPET HOST WORK — see Phase 1.5
# in docs/infrastructure/windows-server-build-runner-plan.md)
#
# Version pin: snapshot-thick → pinning to v4.2.2 release tag at deploy time
# would require a private mirror of the image. Upstream `snapshot-thick` tag
# is updated on every release, so for now we trust upstream + Calico's
# established pattern. Pin to a specific SHA256 once we mirror to Gitea OCI.
#
# Apply (once committed to bluejay-infra main, ApplicationSet auto-syncs):
# git add apps/multus/multus.yaml && git commit && git push origin main
# # ArgoCD `infra-multus` Application appears within 3 min via ApplicationSet
#
# Verify:
# kubectl -n kube-system get ds kube-multus-ds
# kubectl -n kube-system rollout status ds kube-multus-ds
# kubectl get crd network-attachment-definitions.k8s.cni.cncf.io
# =============================================================================
---
apiVersion: apiextensions.k8s.io/v1
kind: CustomResourceDefinition
metadata:
name: network-attachment-definitions.k8s.cni.cncf.io
annotations:
bluejay.iamworkin.lan/source: "k8snetworkplumbingwg/multus-cni v4.2.2"
spec:
group: k8s.cni.cncf.io
scope: Namespaced
names:
plural: network-attachment-definitions
singular: network-attachment-definition
kind: NetworkAttachmentDefinition
shortNames:
- net-attach-def
versions:
- name: v1
served: true
storage: true
schema:
openAPIV3Schema:
description: 'NetworkAttachmentDefinition is a CRD schema specified by the Network Plumbing
Working Group to express the intent for attaching pods to one or more logical or physical
networks. More information available at: https://github.com/k8snetworkplumbingwg/multi-net-spec'
type: object
properties:
apiVersion:
type: string
kind:
type: string
metadata:
type: object
spec:
description: 'NetworkAttachmentDefinition spec defines the desired state of a network attachment'
type: object
properties:
config:
description: 'NetworkAttachmentDefinition config is a JSON-formatted CNI configuration'
type: string
---
kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: multus
rules:
- apiGroups: ["k8s.cni.cncf.io"]
resources:
- '*'
verbs:
- '*'
- apiGroups:
- ""
resources:
- pods
- pods/status
verbs:
- get
- list
- update
- watch
- apiGroups:
- ""
- events.k8s.io
resources:
- events
verbs:
- create
- patch
- update
---
kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1
metadata:
name: multus
roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: multus
subjects:
- kind: ServiceAccount
name: multus
namespace: kube-system
---
apiVersion: v1
kind: ServiceAccount
metadata:
name: multus
namespace: kube-system
---
kind: ConfigMap
apiVersion: v1
metadata:
name: multus-daemon-config
namespace: kube-system
labels:
tier: node
app: multus
data:
daemon-config.json: |
{
"chrootDir": "/hostroot",
"cniVersion": "0.3.1",
"logLevel": "verbose",
"logToStderr": true,
"cniConfigDir": "/host/etc/cni/net.d",
"multusAutoconfigDir": "/host/etc/cni/net.d",
"multusConfigFile": "auto",
"socketDir": "/host/run/multus/"
}
---
apiVersion: apps/v1
kind: DaemonSet
metadata:
name: kube-multus-ds
namespace: kube-system
labels:
tier: node
app: multus
name: multus
spec:
selector:
matchLabels:
name: multus
updateStrategy:
type: RollingUpdate
template:
metadata:
labels:
tier: node
app: multus
name: multus
spec:
hostNetwork: true
hostPID: true
tolerations:
- operator: Exists
effect: NoSchedule
- operator: Exists
effect: NoExecute
serviceAccountName: multus
containers:
- name: kube-multus
image: ghcr.io/k8snetworkplumbingwg/multus-cni:snapshot-thick
command: [ "/usr/src/multus-cni/bin/multus-daemon" ]
# 2026-05-11: upstream default of 50Mi memory limit OOM-cascades when
# an operator-owned namespace accumulates >100 pending pods retrying
# CNI ADD. RemoteDesktop emitted 219 orphan rd-browser-only pods
# (missing OwnerReferences), kubelet's CNI ADD avalanche pushed multus
# over 50Mi, OOMKilled, restarted with even bigger backlog → loop.
# 21h cluster outage. See FlowerCore.Notes:
# feedback_multus_50mi_limit_oom_orphan_pod_avalanche.md
# 1Gi limit / 512Mi request comfortably handles a 200+ pod CNI
# catchup burst on 64GB nodes (nodes are <25% used in steady-state).
# Drop back toward 256Mi only after MultusMemoryPressure alert
# proves steady-state working set sits well below 200Mi.
resources:
requests:
cpu: "100m"
memory: "512Mi"
limits:
cpu: "100m"
memory: "1Gi"
securityContext:
privileged: true
terminationMessagePolicy: FallbackToLogsOnError
volumeMounts:
- name: cni
mountPath: /host/etc/cni/net.d
# multus-daemon expects that cnibin path must be identical between pod and container host.
# e.g. if the cni bin is in '/opt/cni/bin' on the container host side, then it should be mount to '/opt/cni/bin' in multus-daemon,
# not to any other directory, like '/opt/bin' or '/usr/bin'.
- name: cnibin
mountPath: /opt/cni/bin
- name: host-run
mountPath: /host/run
- name: host-var-lib-cni-multus
mountPath: /var/lib/cni/multus
- name: host-var-lib-kubelet
mountPath: /var/lib/kubelet
mountPropagation: HostToContainer
- name: host-run-k8s-cni-cncf-io
mountPath: /run/k8s.cni.cncf.io
- name: host-run-netns
mountPath: /run/netns
mountPropagation: HostToContainer
- name: multus-daemon-config
mountPath: /etc/cni/net.d/multus.d
readOnly: true
- name: hostroot
mountPath: /hostroot
mountPropagation: HostToContainer
- mountPath: /etc/cni/multus/net.d
name: multus-conf-dir
env:
- name: MULTUS_NODE_NAME
valueFrom:
fieldRef:
fieldPath: spec.nodeName
initContainers:
- name: install-multus-binary
image: ghcr.io/k8snetworkplumbingwg/multus-cni:snapshot-thick
command:
- "sh"
- "-c"
- "cp /usr/src/multus-cni/bin/multus-shim /host/opt/cni/bin/multus-shim && cp /usr/src/multus-cni/bin/passthru /host/opt/cni/bin/passthru"
resources:
requests:
cpu: "10m"
memory: "15Mi"
securityContext:
privileged: true
terminationMessagePolicy: FallbackToLogsOnError
volumeMounts:
- name: cnibin
mountPath: /host/opt/cni/bin
mountPropagation: Bidirectional
terminationGracePeriodSeconds: 10
volumes:
- name: cni
hostPath:
path: /etc/cni/net.d
- name: cnibin
hostPath:
path: /opt/cni/bin
- name: hostroot
hostPath:
path: /
- name: multus-daemon-config
configMap:
name: multus-daemon-config
items:
- key: daemon-config.json
path: daemon-config.json
- name: host-run
hostPath:
path: /run
- name: host-var-lib-cni-multus
hostPath:
path: /var/lib/cni/multus
- name: host-var-lib-kubelet
hostPath:
path: /var/lib/kubelet
- name: host-run-k8s-cni-cncf-io
hostPath:
path: /run/k8s.cni.cncf.io
- name: host-run-netns
hostPath:
path: /run/netns/
- name: multus-conf-dir
hostPath:
path: /etc/cni/multus/net.d