kind: [WSL2] Sync failed errors in kube-proxy for Service with SessionAffinity: ClientIP

What happened: iptables fail to be updated on the nodes after a Service with sessionAffinity: ClientIP is created. The issue manifests in requests beeing dropped to any Services that were created after the Service with session affinity.

kube-proxy pod is logging the following error:

E0720 14:29:10.934607       1 proxier.go:1507] Failed to execute iptables-restore: exit status 2 (iptables-restore v1.8.3 (legacy): Couldn't load match `recent':No such file or directory

Error occurred at line: 96
Try `iptables-restore -h' or 'iptables-restore --help' for more information.
)
I0720 14:29:10.934636       1 proxier.go:779] Sync failed; retrying in 30s

What you expected to happen: iptables to be updated correctly so that requests could be routed to any Service in the cluster.

How to reproduce it (as minimally and precisely as possible): Create a Service with sessionAffinity: ClientIP

apiVersion: v1
kind: Service
metadata:
  labels:
    alertmanager: main
  name: alertmanager-main
  namespace: monitoring
spec:
  ports:
  - name: web
    port: 9093
    targetPort: web
  selector:
    alertmanager: main
    app: alertmanager
  sessionAffinity: ClientIP

Anything else we need to know?: Issue is reproducible with both kubeProxyMode: iptables (default) and kubeProxyMode: ipvs

Environment:

• kind version:
  • kind v0.8.1 go1.13.8 linux/amd64
  • kind v0.9.0-alpha+95753c11434213 go1.15beta1 linux/amd64
• Kubernetes version:
  • Server Version: version.Info{Major:"1", Minor:"17", GitVersion:"v1.17.5", GitCommit:"e0fccafd69541e3750d460ba0f9743b90336f24f", GitTreeState:"clean", BuildDate:"2020-05-01T02:11:15Z", GoVersion:"go1.13.9", Compiler:"gc", Platform:"linux/amd64"}
  • also tried v1.18.2 (default with kind v0.8.1) and v1.18.6 (default with kind v0.9.0-alpha)
• Docker version: Docker Desktop with WSL2

Client:
 Debug Mode: false

Server:
 Containers: 1
  Running: 1
  Paused: 0
  Stopped: 0
 Images: 1
 Server Version: 19.03.8
 Storage Driver: overlay2
  Backing Filesystem: <unknown>
  Supports d_type: true
  Native Overlay Diff: true
 Logging Driver: json-file
 Cgroup Driver: cgroupfs
 Plugins:
  Volume: local
  Network: bridge host ipvlan macvlan null overlay
  Log: awslogs fluentd gcplogs gelf journald json-file local logentries splunk syslog
 Swarm: inactive
 Runtimes: runc
 Default Runtime: runc
 Init Binary: docker-init
 containerd version: 7ad184331fa3e55e52b890ea95e65ba581ae3429
 runc version: dc9208a3303feef5b3839f4323d9beb36df0a9dd
 init version: fec3683
 Security Options:
  seccomp
   Profile: default
 Kernel Version: 4.19.104-microsoft-standard
 Operating System: Docker Desktop
 OSType: linux
 Architecture: x86_64
 CPUs: 24
 Total Memory: 25GiB
 Name: docker-desktop
 ID: D4I2:L4Y5:PGPS:CEUY:H3TU:C33L:HASQ:VZKB:53SE:SHQG:OOQV:BZMQ
 Docker Root Dir: /var/lib/docker
 Debug Mode: true
  File Descriptors: 48
  Goroutines: 57
  System Time: 2020-07-20T15:35:34.5632783Z
  EventsListeners: 3
 Registry: https://index.docker.io/v1/
 Labels:
 Experimental: false
 Insecure Registries:
  127.0.0.0/8
 Live Restore Enabled: false
 Product License: Community Engine

WARNING: bridge-nf-call-iptables is disabled
WARNING: bridge-nf-call-ip6tables is disabled

• OS: Windows 10 (Build: 19041.388)