Don't touch ipv6 sysctls when there are no v6 addresses

[squeed]

Sometimes ipv6 is disabled (e.g. via kernel command line)

[squeed]

This was fixed.

[qrpike]

What version of CNI was this released in? I have ipv6 disabled at the kernel. I'm am using CNI v0.6.0
with flannel v0.10.0 and I'm getting the following:

Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547096    2062 remote_runtime.go:92] RunPodSandbox from runtime service failed: rpc error: code = Unknown desc = NetworkPlugin cni failed to set up pod "node-problem-detector-xqp5k_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory
Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547148    2062 kuberuntime_sandbox.go:54] CreatePodSandbox for pod "node-problem-detector-xqp5k_kube-system(7d585c3f-fbee-11e7-b6ee-1eb535d7075a)" failed: rpc error: code = Unknown desc = NetworkPlugin cni failed to set up pod "node-problem-detector-xqp5k_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory
Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547165    2062 kuberuntime_manager.go:647] createPodSandbox for pod "node-problem-detector-xqp5k_kube-system(7d585c3f-fbee-11e7-b6ee-1eb535d7075a)" failed: rpc error: code = Unknown desc = NetworkPlugin cni failed to set up pod "node-problem-detector-xqp5k_kube-system" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory
Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547236    2062 pod_workers.go:186] Error syncing pod 7d585c3f-fbee-11e7-b6ee-1eb535d7075a ("node-problem-detector-xqp5k_kube-system(7d585c3f-fbee-11e7-b6ee-1eb535d7075a)"), skipping: failed to "CreatePodSandbox" for "node-problem-detector-xqp5k_kube-system(7d585c3f-fbee-11e7-b6ee-1eb535d7075a)" with CreatePodSandboxError: "CreatePodSandbox for pod \"node-problem-detector-xqp5k_kube-system(7d585c3f-fbee-11e7-b6ee-1eb535d7075a)\" failed: rpc error: code = Unknown desc = NetworkPlugin cni failed to set up pod \"node-problem-detector-xqp5k_kube-system\" network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory"
Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547441    2062 cni.go:259] Error adding network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory
Jan 29 22:42:34 blade02 kubelet-wrapper[2062]: E0130 03:42:34.547461    2062 cni.go:227] Error while adding to cni network: open /proc/sys/net/ipv6/conf/eth0/accept_dad: no such file or directory

[squeed]

It's not yet been released; we hope to cut a release this week.

[smallem]

Is this fix released now? if Yes, any references as to which flannel-cni version has this fix. I'm using kubespray to deploy kubernetes 1.9.2 using ubuntu 16.04

[PaulFurtado]

@smallem This fix was merged in #62
And it's in the v0.7.0 release: v0.6.0...v0.7.0