Add command.Addwriter() support

pkg/command/command.go

@@ -30,7 +30,8 @@ import (
 
 // A generic command abstraction
 type Command struct {
-	cmds []*command
+	cmds                         []*command
+	stdErrWriters, stdOutWriters []io.Writer
 }
 
 // The internal command representation
@@ -64,6 +65,8 @@ func NewWithWorkDir(workDir, cmd string, args ...string) *Command {
 			Cmd:        cmdWithDir(workDir, cmd, args...),
 			pipeWriter: nil,
 		}},
+		stdErrWriters: []io.Writer{},
+		stdOutWriters: []io.Writer{},
 	}
 }
 
@@ -88,6 +91,29 @@ func (c *Command) Pipe(cmd string, args ...string) *Command {
 	return c
 }
 
+// AddWriter can be used to add an additional output (stdout) and error
+// (stderr) writer to the command, for example when having the need to log to
+// files.
+func (c *Command) AddWriter(writer io.Writer) *Command {
+	c.AddOutputWriter(writer)
+	c.AddErrorWriter(writer)
+	return c
+}
+
+// AddErrorWriter can be used to add an additional error (stderr) writer to the
+// command, for example when having the need to log to files.
+func (c *Command) AddErrorWriter(writer io.Writer) *Command {
+	c.stdErrWriters = append(c.stdErrWriters, writer)
+	return c
+}
+
+// AddOutputWriter can be used to add an additional output (stdout) writer to
+// the command, for example when having the need to log to files.
+func (c *Command) AddOutputWriter(writer io.Writer) *Command {
+	c.stdOutWriters = append(c.stdOutWriters, writer)
+	return c
+}
+
 // Run starts the command and waits for it to finish. It returns an error if
 // the command execution was not possible at all, otherwise the Status.
 // This method prints the commands output during execution
@@ -190,8 +216,12 @@ func (c *Command) run(printOutput bool) (res *Status, err error) {
 
 			var stdOutWriter, stdErrWriter io.Writer
 			if printOutput {
-				stdOutWriter = io.MultiWriter(os.Stdout, stdOutBuffer)
-				stdErrWriter = io.MultiWriter(os.Stderr, stdErrBuffer)
+				stdOutWriter = io.MultiWriter(append(
+					[]io.Writer{os.Stdout, stdOutBuffer}, c.stdOutWriters...,
+				)...)
+				stdErrWriter = io.MultiWriter(append(
+					[]io.Writer{os.Stderr, stdErrBuffer}, c.stdErrWriters...,
+				)...)
 			} else {
 				stdOutWriter = stdOutBuffer
 				stdErrWriter = stdErrBuffer

pkg/command/command_test.go

@@ -17,6 +17,9 @@ limitations under the License.
 package command
 
 import (
+	"bytes"
+	"io/ioutil"
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/require"
@@ -197,3 +200,103 @@ func TestFailureRunSilentSuccessOutput(t *testing.T) {
 	require.NotNil(t, err)
 	require.Nil(t, res)
 }
+
+func TestSuccessLogWriter(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	res, err := New("echo", "Hello World").AddWriter(f).RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Output(), string(content))
+}
+
+func TestSuccessLogWriterMultiple(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+	b := &bytes.Buffer{}
+
+	res, err := New("echo", "Hello World").
+		AddWriter(f).
+		AddWriter(b).
+		RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Output(), string(content))
+	require.Equal(t, res.Output(), b.String())
+}
+
+func TestSuccessLogWriterSilent(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	err = New("echo", "Hello World").AddWriter(f).RunSilentSuccess()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Empty(t, content)
+}
+
+func TestSuccessLogWriterStdErr(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	res, err := New("bash", "-c", ">&2 echo error").
+		AddWriter(f).RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Error(), string(content))
+}
+
+func TestSuccessLogWriterStdErrAndStdOut(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	res, err := New("bash", "-c", ">&2 echo stderr; echo stdout").
+		AddWriter(f).RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Output()+res.Error(), string(content))
+}
+
+func TestSuccessLogWriterStdErrAndStdOutOnlyStdErr(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	res, err := New("bash", "-c", ">&2 echo stderr; echo stdout").
+		AddErrorWriter(f).RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Error(), string(content))
+}
+
+func TestSuccessLogWriterStdErrAndStdOutOnlyStdOut(t *testing.T) {
+	f, err := ioutil.TempFile("", "log")
+	require.Nil(t, err)
+	defer func() { require.Nil(t, os.Remove(f.Name())) }()
+
+	res, err := New("bash", "-c", ">&2 echo stderr; echo stdout").
+		AddOutputWriter(f).RunSuccessOutput()
+	require.Nil(t, err)
+
+	content, err := ioutil.ReadFile(f.Name())
+	require.Nil(t, err)
+	require.Equal(t, res.Output(), string(content))
+}

pkg/gcp/build/build.go

@@ -20,7 +20,6 @@ import (
 	"fmt"
 	"io/ioutil"
 	"os"
-	"os/exec"
 	"path"
 	"path/filepath"
 	"strconv"
@@ -232,7 +231,7 @@ func RunSingleJob(o *Options, jobName, uploaded, version string, subs map[string
 		args = append(args, diskSizeArg)
 	}
 
-	cmd := exec.Command("gcloud", args...)
+	cmd := command.New("gcloud", args...)
 
 	if o.LogDir != "" {
 		p := path.Join(o.LogDir, strings.ReplaceAll(jobName, "/", "-")+".log")
@@ -243,16 +242,11 @@ func RunSingleJob(o *Options, jobName, uploaded, version string, subs map[string
 		}
 
 		defer f.Close()
-
-		cmd.Stdout = f
-		cmd.Stderr = f
-	} else {
-		cmd.Stdout = os.Stdout
-		cmd.Stderr = os.Stderr
+		cmd.AddWriter(f)
 	}
 
-	if err := cmd.Run(); err != nil {
-		return errors.Wrapf(err, "error running %s", cmd.Args)
+	if err := cmd.RunSuccess(); err != nil {
+		return errors.Wrapf(err, "error running %s", cmd.String())
 	}
 
 	return nil