The iptables rules in the nat table POTROUTING chain are out of order

[opengers]

The iptables rules in the nat table POTROUTING chain are out of order

Current Behavior

As above, it's a kubernetes node, the last 4 rules are out of order, The normal order should be RETURN, then MASQUERADE, then RETURN, then MASQUERADE

Steps to Reproduce (for bugs)

This problem occurs randomly, so I cannot reproduce it

Context

The temporary workaround is to manually delete a rule, and then wait for flannel to set a new correct rule.

And I found that the version of iptables in the image of gcr/coreos-flannel:v0.9.1 is 1.4.21, iptables does not use the lock file when running, as shown below

Your Environment

• Flannel version: 0.9.1
• vxlan
• Kubernetes version: 1.13.5 + canal(calico, flannel)
• Operating System and version: ubuntu16.04