add CNI config validation to getDefaultCNINetwork

[mars1024]

What type of PR is this?

/kind bug

What this PR does / why we need it:

If we use a CNI config file contains plugins ptp and bandwidth, just like

{
  "cniVersion": "0.3.1",
  "name": "mynet",
  "plugins": [
    {
      "type": "ptp",
      "ipam": {
          "type": "host-local",
          "subnet": "10.0.0.0/24"
      }
    },
    {
      "name": "slowdown",
      "type": "bandwidth",
      "capabilities": {
      	"bandwidth": true
      }
    }
  ]
}

and bandwidth plugin is not on disk.

cniNetworkPlugin.SetUpPod will fail because we can't find bandwidth plugin, then cniNetworkPlugin.TearDownPod will be called to recycle container network, we all know plugins are called in reverse order in CNI DEL, so teardown will fail in calling bandwidth plugin without calling ptp plugin, so CNI DEL of ptp plugin is actually not done for container, this leads to some problems, one of these is IP leak.

So I use CNI validation to check the presence of plugins before setup/teardown pods, which can prevent the happening above.

NONE

[k8s-ci-robot]

Hi @mars1024. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[dcbw]

/ok-to-test

[dcbw]

@squeed

[yue9944882]

/retest

[squeed]

By the way, thanks a lot for implementing this. I wrote ValidatePluginList() with the intention of adding it to dockershim, then never had time to do it. I'm really glad you did :-).

[mars1024]

By the way, thanks a lot for implementing this. I wrote ValidatePluginList() with the intention of adding it to dockershim, then never had time to do it. I'm really glad you did :-).

My pleasure :), and thanks for your contributions in libcni.

[mars1024]

/retest

[mars1024]

Updated! PTAL, thanks ! @dcbw @rramkumar1 cc @squeed

[squeed]

/lgtm

[mars1024]

/assign @dcbw

[mars1024]

@dcbw @freehan Do you have time to promote this PR? Thanks

[zuoxiu-antfinancial]

/retest

[mars1024]

@dcbw @freehan Any suggestions or approves? Looking forward to your reply ~

[mars1024]

@squeed Squash make label lgtm removed, could you do me a favor to add it back ? No code changes expect a commits squash.

[squeed]

/lgtm

[mars1024]

/retest

[mars1024]

@dcbw @freehan @thockin Could you help to approve this PR?

[mars1024]

/assign @thockin

[thockin]

Thanks!

/approve

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: mars1024, thockin

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