Remove util package, it was only used by cli/main.go

`util` is not a great name, it has no context and can quickly become a
place where we put everything and anything.

cli/main.go

@@ -33,7 +33,9 @@ import (
 	"log"
 	"os"
 	"os/exec"
+	"os/signal"
 	"path/filepath"
+	"syscall"
 
 	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
@@ -48,7 +50,6 @@ import (
 	"github.com/docker/api/cli/cmd/run"
 	apicontext "github.com/docker/api/context"
 	"github.com/docker/api/context/store"
-	"github.com/docker/api/util"
 )
 
 var (
@@ -129,7 +130,7 @@ func main() {
 		logrus.SetLevel(logrus.DebugLevel)
 	}
 
-	ctx, cancel := util.NewSigContext()
+	ctx, cancel := newSigContext()
 	defer cancel()
 
 	config, err := apicontext.LoadConfigFile(opts.Config, "config.json")
@@ -167,6 +168,17 @@ func main() {
 	}
 }
 
+func newSigContext() (context.Context, func()) {
+	ctx, cancel := context.WithCancel(context.Background())
+	s := make(chan os.Signal)
+	signal.Notify(s, syscall.SIGTERM, syscall.SIGINT)
+	go func() {
+		<-s
+		cancel()
+	}()
+	return ctx, cancel
+}
+
 func execMoby(ctx context.Context) {
 	currentContext := apicontext.CurrentContext(ctx)
 	s := store.ContextStore(ctx)

util/util.go

@@ -1,48 +0,0 @@
-/*
-	Copyright (c) 2020 Docker Inc.
-
-	Permission is hereby granted, free of charge, to any person
-	obtaining a copy of this software and associated documentation
-	files (the "Software"), to deal in the Software without
-	restriction, including without limitation the rights to use, copy,
-	modify, merge, publish, distribute, sublicense, and/or sell copies
-	of the Software, and to permit persons to whom the Software is
-	furnished to do so, subject to the following conditions:
-
-	The above copyright notice and this permission notice shall be
-	included in all copies or substantial portions of the Software.
-
-	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
-	EXPRESS OR IMPLIED,
-	INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
-	IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
-	HOLDERS BE LIABLE FOR ANY CLAIM,
-	DAMAGES OR OTHER LIABILITY,
-	WHETHER IN AN ACTION OF CONTRACT,
-	TORT OR OTHERWISE,
-	ARISING FROM, OUT OF OR IN CONNECTION WITH
-	THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
-*/
-
-package util
-
-import (
-	"context"
-	"os"
-	"os/signal"
-	"syscall"
-)
-
-// NewSigContext is a context that is canceled when a signal is
-// sent to the process
-func NewSigContext() (context.Context, func()) {
-	ctx, cancel := context.WithCancel(context.Background())
-	s := make(chan os.Signal)
-	signal.Notify(s, syscall.SIGTERM, syscall.SIGINT)
-	go func() {
-		<-s
-		cancel()
-	}()
-	return ctx, cancel
-}