Add commander for excuting commands

Author: arunvelsriram

pkg/commander/commander.go

@@ -0,0 +1,28 @@
+package commander
+
+import (
+	"os"
+	"os/exec"
+)
+
+// Commander is an interface to execute commands
+type Commander interface {
+	Execute(cmd string, args []string) ([]string, error)
+}
+
+// Default is a Commander implementation that
+// can execute commands on a actual machine
+type Default struct{}
+
+// Execute executes a command on the actual machine
+func (Default) Execute(cmdStr string, args []string, envs []string) (string, error) {
+	cmd := exec.Command(cmdStr, args...)
+	cmd.Env = os.Environ()
+	cmd.Env = append(cmd.Env, envs...)
+	out, err := cmd.Output()
+	if err != nil {
+		return string(out), err
+	}
+
+	return string(out), nil
+}

pkg/commander/commander_test.go

@@ -0,0 +1,34 @@
+package commander_test
+
+import (
+	"testing"
+
+	"github.com/arunvelsriram/kube-tmuxp/pkg/commander"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestExecute(t *testing.T) {
+	t.Run("should execute command on the machine", func(t *testing.T) {
+		cmdr := commander.Default{}
+		out, err := cmdr.Execute("echo", []string{"-n", "test"}, []string{})
+
+		assert.Nil(t, err)
+		assert.Equal(t, "test", out)
+	})
+
+	t.Run("should be able to set env variables for a command", func(t *testing.T) {
+		cmdr := commander.Default{}
+		out, err := cmdr.Execute("env", []string{}, []string{"TEST_ENV=test"})
+
+		assert.Nil(t, err)
+		assert.Contains(t, out, "TEST_ENV=test")
+	})
+
+	t.Run("should return error if execution fails", func(t *testing.T) {
+		cmdr := commander.Default{}
+		out, err := cmdr.Execute("invalid-cmd", []string{}, []string{})
+
+		assert.NotNil(t, err)
+		assert.Equal(t, "", out)
+	})
+}