Create new hyperkube package.

This is the start of an uber-binary that can morph into any server.  Eventually we'll want this to be able to launch multiple servers from a single command line.

pkg/hyperkube/hyperkube.go

@@ -0,0 +1,184 @@
+/*
+Copyright 2014 Google Inc. All rights reserved.
+
+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 hyperkube
+
+import (
+	"errors"
+	"flag"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"path"
+
+	"github.com/GoogleCloudPlatform/kubernetes/pkg/util"
+
+	"github.com/spf13/pflag"
+)
+
+// HyperKube represents a single binary that can morph/manage into multiple
+// servers.
+type HyperKube struct {
+	Name string // The executable name, used for help and soft-link invocation
+	Long string // A long description of the binary.  It will be world wrapped before output.
+
+	servers     []Server
+	baseFlags   *pflag.FlagSet
+	out         io.Writer
+	helpFlagVal bool
+}
+
+// AddServer adds a server to the HyperKube object.
+func (hk *HyperKube) AddServer(s *Server) {
+	hk.servers = append(hk.servers, *s)
+	hk.servers[len(hk.servers)-1].hk = hk
+}
+
+// FindServer will find a specific server named name.
+func (hk *HyperKube) FindServer(name string) (*Server, error) {
+	for _, s := range hk.servers {
+		if s.Name() == name {
+			return &s, nil
+		}
+	}
+	return nil, fmt.Errorf("Server not found: %s", name)
+}
+
+// Servers returns a list of all of the registred servers
+func (hk *HyperKube) Servers() []Server {
+	return hk.servers
+}
+
+// Flags returns a flagset for "global" flags.
+func (hk *HyperKube) Flags() *pflag.FlagSet {
+	if hk.baseFlags == nil {
+		hk.baseFlags = pflag.NewFlagSet(hk.Name, pflag.ContinueOnError)
+		hk.baseFlags.SetOutput(ioutil.Discard)
+		hk.baseFlags.BoolVarP(&hk.helpFlagVal, "help", "h", false, "help for "+hk.Name)
+
+		// These will add all of the "global" flags (defined with both the
+		// flag and pflag packages) to the new flag set we have.
+		util.AddFlagSetToPFlagSet(flag.CommandLine, hk.baseFlags)
+		util.AddPFlagSetToPFlagSet(pflag.CommandLine, hk.baseFlags)
+
+	}
+	return hk.baseFlags
+}
+
+// Out returns the io.Writer that is used for all usage/error information
+func (hk *HyperKube) Out() io.Writer {
+	if hk.out == nil {
+		hk.out = os.Stderr
+	}
+	return hk.out
+}
+
+// SetOut sets the output writer for all usage/error information
+func (hk *HyperKube) SetOut(w io.Writer) {
+	hk.out = w
+}
+
+// Print is a convenience method to Print to the defined output
+func (hk *HyperKube) Print(i ...interface{}) {
+	fmt.Fprint(hk.Out(), i...)
+}
+
+// Println is a convenience method to Println to the defined output
+func (hk *HyperKube) Println(i ...interface{}) {
+	str := fmt.Sprintln(i...)
+	hk.Print(str)
+}
+
+// Printf is a convenience method to Printf to the defined output
+func (hk *HyperKube) Printf(format string, i ...interface{}) {
+	str := fmt.Sprintf(format, i...)
+	hk.Print(str)
+}
+
+// Run the server.  This will pick the appropriate server and run it.
+func (hk *HyperKube) Run(args []string) error {
+	// If we are called directly, parse all flags up to the first real
+	// argument.  That should be the server to run.
+	baseCommand := path.Base(args[0])
+	serverName := baseCommand
+	if serverName == hk.Name {
+		args = args[1:]
+
+		baseFlags := hk.Flags()
+		baseFlags.SetInterspersed(false) // Only parse flags up to the next real command
+		err := baseFlags.Parse(args)
+		if err != nil || hk.helpFlagVal {
+			if err != nil {
+				hk.Println("Error:", err)
+			}
+			hk.Usage()
+			return err
+		}
+		args = baseFlags.Args()
+		if len(args) > 0 && len(args[0]) > 0 {
+			serverName = args[0]
+			baseCommand = baseCommand + " " + serverName
+			args = args[1:]
+		} else {
+			err = errors.New("No server specified")
+			hk.Println("Error", err)
+			hk.Usage()
+			return err
+		}
+	}
+
+	s, err := hk.FindServer(serverName)
+	if err != nil {
+		hk.Println("Error:", err)
+		hk.Usage()
+		return err
+	}
+
+	util.AddPFlagSetToPFlagSet(hk.Flags(), s.Flags())
+	err = s.Flags().Parse(args)
+	if err != nil || hk.helpFlagVal {
+		if err != nil {
+			hk.Println("Error:", err)
+		}
+		s.Usage()
+		return err
+	}
+
+	util.InitLogs()
+	err = s.Run(s, s.Flags().Args())
+	if err != nil {
+		hk.Println("Error:", err)
+	}
+
+	return err
+}
+
+// Usage will write out a summary for all servers that this binary supports.
+func (hk *HyperKube) Usage() {
+	tt := `{{if .Long}}{{.Long | trim | wrap ""}}
+{{end}}Usage
+
+  {{.Name}} <server> [flags]
+
+Servers
+{{range .Servers}}
+  {{.Name}}
+{{.Long | trim | wrap "    "}}{{end}}
+Call '{{.Name}} <server> --help' for help on a specific server.
+`
+	util.ExecuteTemplate(hk.Out(), tt, hk)
+}