executor调用cni插件时没有进行错误判断，导致cni调用失败时触发executor异常[bug]

[abstractmj]

问题描述

bk-bcs/bcs-mesos/bcs-container-executor/network/cni/cni.go
代码没有进行错误处理，导致cni插件如果返回error，executor会出现空指针错误，虽然executor有对runtime error的recover，但是会造成list taskgroup时显示bcs-executor is down，造成误解
func (plugin *CNIPlugin) addNetworkV2(runConf *libcni.RuntimeConf) (*current.Result, error) {
var err error
var r cnitypes.Result
if plugin.isCniList {
r, err = plugin.cniNet.AddNetworkList(plugin.netConfList, runConf)

} else {
	r, err = plugin.cniNet.AddNetwork(plugin.netConf, runConf)
}

重现方法

• 调用cni插件返回错误时，可以耗尽IP地址，也可以将cni的conf文件修改成错的

./bcs-container-executor --version 输出的内容:
Version :1.13.2-alpha-19.07.02
Tag :1.13.2-alpha
BuildTime: 2019-07-02T15:23:25+0800
GitHash: 9097082

2019/07/11 17:33:48 BcsExecutor init pod success.
2019/07/11 17:33:48 CNI plugin manager ADD pod c9e885877b25db3f35885b9dbcf4ad0927f2976d9fad0ae3a18bb84b6f717029 network with bcs-qcloud
2019/07/11 17:33:48 CNI plugin bcs-qcloud set conf {"ContainerID":"c9e885877b25db3f35885b9dbcf4ad0927f2976d9fad0ae3a18bb84b6f717029","NetNS":"/proc/15264/ns/net","IfName":"eth1","Args":[["IgnoreUnknown","true"]],"CapabilityArgs":null}
2019/07/11 17:33:48 Lauch panic: runtime error: invalid memory address or nil pointer dereference
2019/07/11 17:33:48 CNIPod prepare to stop 0 running containers
2019/07/11 17:33:48 CNIPod stop 0 running containers done
2019/07/11 17:33:48 Task 1562837627857764032.0.2.test.test.10000 Update Status TASK_FAILED, Message: bcs executor down