IPVS services periodic sync panics due to modprobe failure

[murali-reddy]

This is stack trace, need further investigation.

panic: Running modprobe ip_vs failed with message: ``, error: fork/exec /sbin/modprobe: too many open files

goroutine 95 [running]:
panic(0x15458e0, 0xc42118d990)
/usr/local/go/src/runtime/panic.go:500 +0x1a1
github.com/cloudnativelabs/kube-router/app/controllers.ipvsAddService(0xc42118c820, 0x10, 0x10, 0x101bb0006, 0xc42118d501, 0x4, 0x0)
/home/kube/go/src/github.com/cloudnativelabs/kube-router/app/controllers/network_services_controller.go:399 +0x964
github.com/cloudnativelabs/kube-router/app/controllers.(*NetworkServicesController).syncIpvsServices(0xc4203924d0, 0xc420a7ade0, 0xc420a7aed0)
/home/kube/go/src/github.com/cloudnativelabs/kube-router/app/controllers/network_services_controller.go:205 +0x3cb
github.com/cloudnativelabs/kube-router/app/controllers.(*NetworkServicesController).sync(0xc4203924d0)
/home/kube/go/src/github.com/cloudnativelabs/kube-router/app/controllers/network_services_controller.go:126 +0xbf
github.com/cloudnativelabs/kube-router/app/controllers.(*NetworkServicesController).Run(0xc4203924d0, 0xc42033a4e0, 0xc4202e27b0)
/home/kube/go/src/github.com/cloudnativelabs/kube-router/app/controllers/network_services_controller.go:106 +0x1d2
created by github.com/cloudnativelabs/kube-router/app.(*KubeRouter).Run
/home/kube/go/src/github.com/cloudnativelabs/kube-router/app/server.go:146 +0x4ec