Simple implementation of the tillerless mode (#531)

Ref #449

helmexec/runner.go

@@ -1,7 +1,9 @@
 package helmexec
 
 import (
+	"os"
 	"os/exec"
+	"strings"
 )
 
 const (
@@ -11,7 +13,7 @@ const (
 
 // Runner interface for shell commands
 type Runner interface {
-	Execute(cmd string, args []string) ([]byte, error)
+	Execute(cmd string, args []string, env map[string]string) ([]byte, error)
 }
 
 // ShellRunner implemention for shell commands
@@ -20,8 +22,34 @@ type ShellRunner struct {
 }
 
 // Execute a shell command
-func (shell ShellRunner) Execute(cmd string, args []string) ([]byte, error) {
+func (shell ShellRunner) Execute(cmd string, args []string, env map[string]string) ([]byte, error) {
 	preparedCmd := exec.Command(cmd, args...)
 	preparedCmd.Dir = shell.Dir
+	preparedCmd.Env = mergeEnv(os.Environ(), env)
 	return preparedCmd.CombinedOutput()
 }
+
+func mergeEnv(orig []string, new map[string]string) []string {
+	wanted := env2map(orig)
+	for k, v := range new {
+		wanted[k] = v
+	}
+	return map2env(wanted)
+}
+
+func map2env(wanted map[string]string) []string {
+	result := []string{}
+	for k, v := range wanted {
+		result = append(result, k+"="+v)
+	}
+	return result
+}
+
+func env2map(env []string) map[string]string {
+	wanted := map[string]string{}
+	for _, cur := range env {
+		pair := strings.SplitN(cur, "=", 2)
+		wanted[pair[0]] = pair[1]
+	}
+	return wanted
+}