Split implementations from generic code

controllers/nginx/pkg/cmd/controller/utils.go

@@ -0,0 +1,62 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package main
+
+import (
+	"io/ioutil"
+	"os"
+	"os/exec"
+
+	"k8s.io/kubernetes/pkg/util/sysctl"
+
+	"github.com/golang/glog"
+)
+
+// 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
+}
+
+func diff(b1, b2 []byte) ([]byte, error) {
+	f1, err := ioutil.TempFile("", "a")
+	if err != nil {
+		return nil, err
+	}
+	defer f1.Close()
+	defer os.Remove(f1.Name())
+
+	f2, err := ioutil.TempFile("", "b")
+	if err != nil {
+		return nil, err
+	}
+	defer f2.Close()
+	defer os.Remove(f2.Name())
+
+	f1.Write(b1)
+	f2.Write(b2)
+
+	out, _ := exec.Command("diff", "-u", f1.Name(), f2.Name()).CombinedOutput()
+	return out, nil
+}