Extract our default PATH value to a constant for great reuse

Docker-DCO-1.1-Signed-off-by: Andrew Page <admwiggin@gmail.com> (github: tianon)

buildfile.go

@@ -110,7 +110,7 @@ func (b *buildFile) CmdFrom(name string) error {
 		b.config = image.Config
 	}
 	if b.config.Env == nil || len(b.config.Env) == 0 {
-		b.config.Env = append(b.config.Env, "HOME=/", "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin")
+		b.config.Env = append(b.config.Env, "HOME=/", "PATH="+defaultPathEnv)
 	}
 	// Process ONBUILD triggers if they exist
 	if nTriggers := len(b.config.OnBuild); nTriggers != 0 {

container.go

@@ -23,6 +23,8 @@ import (
 	"time"
 )
 
+const defaultPathEnv = "/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
+
 var (
 	ErrNotATTY               = errors.New("The PTY is not a file")
 	ErrNoTTY                 = errors.New("No PTY found")
@@ -447,7 +449,7 @@ func (container *Container) Start() (err error) {
 	// Setup environment
 	env := []string{
 		"HOME=/",
-		"PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin",
+		"PATH=" + defaultPathEnv,
 		"HOSTNAME=" + container.Config.Hostname,
 	}
 

links/links.go

@@ -72,7 +72,7 @@ func (l *Link) ToEnv() []string {
 			if len(parts) != 2 {
 				continue
 			}
-			// Ignore a few variables that are added during docker build
+			// Ignore a few variables that are added during docker build (and not really relevant to linked containers)
 			if parts[0] == "HOME" || parts[0] == "PATH" {
 				continue
 			}