Rmove UseIsolatedEnv from system.Command

This struct attribute is only ever set to `true` by the bosh-cli, and
the value if this use case is in question, see:
- cloudfoundry/bosh-cli#660
- cloudfoundry/bosh-cli#663
- cloudfoundry/bosh-cli#673

In addition the `UseIsolatedEnv` capability can be wholely handled
within the `bosh-cli` codebase itself without the need for this featuer
in `bosh-utils`.

Author: aramprice

system/cmd_runner_interface.go

@@ -6,10 +6,9 @@ import (
 )
 
 type Command struct {
-	Name           string
-	Args           []string
-	Env            map[string]string
-	UseIsolatedEnv bool
+	Name string
+	Args []string
+	Env  map[string]string
 
 	WorkingDir string
 

system/exec_cmd_runner.go

@@ -3,7 +3,6 @@ package system
 import (
 	"os"
 	"os/exec"
-	"runtime"
 	"strings"
 
 	boshlog "github.com/cloudfoundry/bosh-utils/logger"
@@ -80,15 +79,7 @@ func (r execCmdRunner) buildComplexCommand(cmd Command) *exec.Cmd {
 
 	execCmd.Dir = cmd.WorkingDir
 
-	var env []string
-	if !cmd.UseIsolatedEnv {
-		env = os.Environ()
-	}
-	if cmd.UseIsolatedEnv && runtime.GOOS == "windows" {
-		panic("UseIsolatedEnv is not supported on Windows")
-	}
-
-	execCmd.Env = mergeEnv(env, cmd.Env)
+	execCmd.Env = mergeEnv(os.Environ(), cmd.Env)
 
 	return execCmd
 }

system/exec_cmd_runner_test.go

@@ -126,7 +126,6 @@ var _ = Describe("execCmdRunner", func() {
 
 		It("run complex command with env", func() {
 			cmd := GetPlatformCommand("env")
-			cmd.UseIsolatedEnv = false
 			stdout, stderr, status, err := runner.RunComplexCommand(cmd)
 			Expect(err).ToNot(HaveOccurred())
 
@@ -137,23 +136,6 @@ var _ = Describe("execCmdRunner", func() {
 			Expect(status).To(Equal(0))
 		})
 
-		It("runs complex command with specific env", func() {
-			cmd := GetPlatformCommand("env")
-			cmd.UseIsolatedEnv = true
-			if runtime.GOOS == "windows" {
-				Expect(func() { runner.RunComplexCommand(cmd) }).To(Panic()) //nolint:errcheck
-			} else {
-				stdout, stderr, status, err := runner.RunComplexCommand(cmd)
-				Expect(err).ToNot(HaveOccurred())
-
-				envVars := parseEnvFields(stdout, true)
-				Expect(envVars).To(HaveKeyWithValue("FOO", "BAR"))
-				Expect(envVars).ToNot(HaveKey("PATH"))
-				Expect(stderr).To(BeEmpty())
-				Expect(status).To(Equal(0))
-			}
-		})
-
 		setupWindowsEnvTest := func(cmdVars map[string]string) (map[string]string, error) {
 			os.Setenv("_FOO", "BAR") //nolint:errcheck
 			defer os.Unsetenv("_FOO")
@@ -319,7 +301,6 @@ var _ = Describe("execCmdRunner", func() {
 
 		It("allows setting custom env variable in addition to inheriting process env variables", func() {
 			cmd := GetPlatformCommand("env")
-			cmd.UseIsolatedEnv = false
 
 			process, err := runner.RunComplexCommandAsync(cmd)
 			Expect(err).ToNot(HaveOccurred())