nicolaka/netshoot:v0.11 (the pinned tag actually in use) is built on
Alpine 3.18.0, where ip6tables is packaged separately from iptables;
this image's Dockerfile only installs the latter, so ip6tables does
not exist in the container at all (confirmed live: "ip6tables: not
found", and against Alpine's own v3.18 package index, not master's).
Write 1 to /proc/sys/net/ipv6/conf/all/disable_ipv6 instead - per the
kernel's own ip-sysctl docs this is equivalent to also setting
conf/default/disable_ipv6 and every existing per-interface
disable_ipv6 (lo/eth0/net1) at once, and is strictly stronger than an
iptables DROP policy would have been: no IPv6 activity happens on any
interface at all, not just filtered output. Needs no capability beyond
the NET_ADMIN the guard init container already has.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Diagnosed the vlan50-canary FailedCreatePodSandBox->net1-timeout failure
as a stale Pod artifact of the Multus DaemonSet rollout race (sandbox
created via a transient daemon/shim state mid-rollout; the current,
fully-settled daemon's own logs show no ADD for that UID, only a DEL).
No defect found in 02-daemonset.yaml or 10-nad-vlan50.yaml; both are
unchanged.
Independent of that diagnosis, harden the shared guard script per
review: print safe interface/address/route diagnostics before every
FATAL exit; validate net1 actually carries the workload's expected
static /24 address rather than just existing; add arping-based
duplicate-address and gateway-reachability checks before installing
the net1 default route (exit-code semantics verified against arping's
own source). Requires EXPECTED_VLAN50_IP and NET_RAW (for arping's raw
ARP sockets) on every consumer - wired into 20-canary.yaml now,
qbittorrent.yaml/jdownloader.yaml need the same when they're migrated.
Document the canary's Pod lifecycle: restartPolicy: Never means a
Failed canary never reruns on its own, and Argo "Synced" only reflects
manifest match, not runtime success - recreate it (new UID) after any
Multus/CNI change before trusting its result. Recommend keeping it a
manually recreated, controller-less Pod rather than a Job/Deployment,
since unattended auto-retry risks a duplicate-address race on its
static .100 IP - the exact class of bug this diagnosis just walked
through.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
k3s deliberately ships only the plugins its own flannel networking
needs (bandwidth, bridge, firewall, flannel, host-local, loopback,
portmap — confirmed against k3s's own build script; macvlan's absence
is an intentional upstream scope decision, k3s-io/k3s#9224). Multus's
macvlan delegate for the vlan50 NAD therefore had nothing to exec even
after the binDir/mount fixes.
Add a cni-plugins init container mirroring Rancher's own official
rke2-multus Helm chart (the fix k3s's own docs recommend for this
exact gap): rancher/hardened-cni-plugins, digest-pinned, writing into
our existing cnibin mount instead of the image's hardcoded
/opt/cni/bin, with SKIP_CNI_BINARIES=flannel so it doesn't overwrite
k3s's already-working flannel plugin.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
binDir alone (previous commit) wasn't sufficient: k3s's plugin bin dir
is a directory of symlinks into a content-hash-named sibling directory,
and the narrow cnibin mount didn't cover that sibling. FindInPath's
os.Stat follows symlinks, so it failed inside the container even though
the same path resolves fine on the real host. Mount the parent
(k3s-cni-data) into the main container instead so the symlinks resolve;
the init container keeps the narrower cnibin mount since it only writes
files and never follows them.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Root cause: Multus's ChrootExec resolves a delegate plugin's absolute
path from the daemon container's own filesystem view, then execs that
exact path string after chrooting into the real host root. binDir
defaulted to /opt/cni/bin, which is valid inside the container (bind-
mounted to k3s's real bin dir) but doesn't exist on the actual host, so
every pod attaching to the VLAN 50 NAD failed FailedCreatePodSandBox
trying to delegate to flannel. Confirmed against multus-cni's source at
the exact pinned v4.3.0 tag, not assumed. Sets binDir explicitly to
k3s's real path and matches the cnibin mount path to it on both sides of
the chroot boundary (main container and the install_multus init
container).
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
CRD, RBAC, thick-plugin DaemonSet (nik-debian only, k3s CNI paths,
digest-pinned), the VLAN 50 NAD (macvlan bridge on enp1s0.50), the
shared pod egress-guard script, a temporary canary pod, and the
not-yet-deployed browser-vpn-proxy workload (kept in reserved/, outside
this Application's non-recursive source path).
Referenced by argocd/apps/multus.yaml (already pushed) but not deployed
by it — that Application has no syncPolicy.automated, so this still
needs an explicit selective sync per resource.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
