Add healthz tests

pkg/ingress/controller/util.go

@@ -17,11 +17,14 @@ limitations under the License.
 package controller
 
 import (
+	"syscall"
+
 	"github.com/golang/glog"
 
 	"github.com/imdario/mergo"
 
 	api "k8s.io/api/core/v1"
+	"k8s.io/kubernetes/pkg/util/sysctl"
 
 	"k8s.io/ingress-nginx/pkg/ingress"
 )
@@ -53,3 +56,38 @@ func mergeLocationAnnotations(loc *ingress.Location, anns map[string]interface{}
 		glog.Errorf("unexpected error merging extracted annotations in location type: %v", err)
 	}
 }
+
+// sysctlSomaxconn returns the value of net.core.somaxconn, i.e.
+// maximum number of connections that can be queued for acceptance
+// http://nginx.org/en/docs/http/ngx_http_core_module.html#listen
+func sysctlSomaxconn() int {
+	maxConns, err := sysctl.New().GetSysctl("net/core/somaxconn")
+	if err != nil || maxConns < 512 {
+		glog.V(3).Infof("system net.core.somaxconn=%v (using system default)", maxConns)
+		return 511
+	}
+
+	return maxConns
+}
+
+// sysctlFSFileMax returns the value of fs.file-max, i.e.
+// maximum number of open file descriptors
+func sysctlFSFileMax() int {
+	var rLimit syscall.Rlimit
+	err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &rLimit)
+	if err != nil {
+		glog.Errorf("unexpected error reading system maximum number of open file descriptors (RLIMIT_NOFILE): %v", err)
+		// returning 0 means don't render the value
+		return 0
+	}
+	return int(rLimit.Max)
+}
+
+func intInSlice(i int, list []int) bool {
+	for _, v := range list {
+		if v == i {
+			return true
+		}
+	}
+	return false
+}