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Capture StdErr in command execution error #35

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Capture StdErr in command execution error #35

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970cd62
Initial commit to include stderr in error returned by executing command
mayankdaruka-msft May 23, 2024
df075ed
Fix test
mayankdaruka-msft May 23, 2024
0654652
Fix test
mayankdaruka-msft May 23, 2024
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16 changes: 10 additions & 6 deletions pkg/commandhandler/cmd.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3,13 +3,14 @@
package commandhandler

import (
"github.com/Azure/azure-extension-platform/pkg/constants"
"github.com/Azure/azure-extension-platform/pkg/logging"
"github.com/pkg/errors"
"io"
"os"
"os/exec"
"path/filepath"

"github.com/Azure/azure-extension-platform/pkg/constants"
"github.com/Azure/azure-extension-platform/pkg/logging"
"github.com/pkg/errors"
)

type ICommandHandler interface {
Expand Down Expand Up @@ -70,10 +71,13 @@ func execCmdInDirWithAction(cmd, workingDir, logDir string, waitForCompletion bo
stdOutFile.Close()
}

stdErrFile, err3 := os.OpenFile(errFileName, os.O_RDONLY, constants.FilePermissions_UserOnly_ReadWrite)
stdErrContents, err3 := os.ReadFile(errFileName)
if err3 == nil {
el.InfoFromStream("stderr:", stdErrFile)
stdErrFile.Close()
el.Info("stderr: %s", stdErrContents)
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@jscalev jscalev May 23, 2024

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Unfortunately, my fear here is that we've dodged a security issue with a bug that causes these events to not reach Kusto. There's a high likelihood that these events will contain security credentials.

Please check with Norberto and Simon on whether there's any plan to scrub these generically for creds. Otherwise, I fear we may have to replicate the logic we have for the BI data to scrub them here.


if execErr != nil {
return exitCode, errors.Wrap(execErr, string(stdErrContents))
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@jscalev jscalev May 23, 2024

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We probably shouldn't fail the command if we can't read the standard error, right?

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@mayankdaruka-msft mayankdaruka-msft May 23, 2024

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Yeah, I didn't change the behavior with regards to that.
If the command execution results in an error, and we are able to read the standard error, then we return a combined error. Otherwise, we just return the original error at the end of the function.

}
}

} else {
Expand Down
17 changes: 16 additions & 1 deletion pkg/commandhandler/cmd_linux_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,11 +4,13 @@ package commandhandler

import (
"encoding/json"
"github.com/stretchr/testify/assert"
"io/ioutil"
"os"
"path"
"strings"
"testing"

"github.com/stretchr/testify/assert"
)

const (
Expand Down Expand Up @@ -97,3 +99,16 @@ func TestCommandWithEnvironmentVariableEmpty(t *testing.T) {
assert.NoError(t, err, "stdout file should be read")
assert.Contains(t, string(fileInfo), "", "stdout message should be as expected")
}

func TestNonExistingCommand(t *testing.T) {
defer cleanupTest()
cmd := New()
retcode, err := cmd.Execute("command_does_not_exist", workingDir, workingDir, true, extensionLogger)
assert.Equal(t, commandNotExistReturnCode, retcode)
assert.Error(t, err, "command execution should fail")
assert.Contains(t, err.Error(), "command_does_not_exist: not found", "error returned by cmd.Execute should include stderr")

fileInfo, err := os.ReadFile(path.Join(workingDir, "stderr"))
assert.NoError(t, err, "stderr file should be read")
assert.Contains(t, string(fileInfo), "command_does_not_exist: not found", "stderr message should be as expected")
}
13 changes: 3 additions & 10 deletions pkg/commandhandler/cmd_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3,13 +3,14 @@
package commandhandler

import (
"github.com/Azure/azure-extension-platform/pkg/logging"
"github.com/stretchr/testify/assert"
"io/ioutil"
"os"
"path"
"strings"
"testing"

"github.com/Azure/azure-extension-platform/pkg/logging"
"github.com/stretchr/testify/assert"
)

var workingDir = path.Join(".", "testdir", "currentWorkingDir")
Expand Down Expand Up @@ -43,11 +44,3 @@ func TestStderr(t *testing.T) {
stdoutResult := strings.TrimSuffix(strings.TrimSuffix(string(fileBytes), lineReturnCharacter), " ")
assert.Equal(t, "1 2 3 4", stdoutResult)
}

func TestNonExistingCommand(t *testing.T) {
defer cleanupTest()
cmd := New()
retcode, err := cmd.Execute("command_does_not_exist", workingDir, workingDir, true, extensionLogger)
assert.Equal(t, commandNotExistReturnCode, retcode)
assert.Error(t, err)
}
16 changes: 15 additions & 1 deletion pkg/commandhandler/cmd_windows_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -4,12 +4,13 @@ package commandhandler

import (
"encoding/json"
"github.com/stretchr/testify/assert"
"io/ioutil"
"os"
"path"
"testing"
"time"

"github.com/stretchr/testify/assert"
)

const (
Expand Down Expand Up @@ -140,3 +141,16 @@ func TestDoesntWaitForCompletionEnvironmentVariable(t *testing.T) {
duration := endTime.Sub(startTime)
assert.Less(t, duration, time.Second, "execute shouldn't block")
}

func TestNonExistingCommand(t *testing.T) {
defer cleanupTest()
cmd := New()
retcode, err := cmd.Execute("command_does_not_exist", workingDir, workingDir, true, extensionLogger)
assert.Equal(t, commandNotExistReturnCode, retcode)
assert.Error(t, err, "command execution should fail")
assert.Contains(t, err.Error(), "is not recognized as an internal or external command", "error returned by cmd.Execute should include stderr")

fileInfo, err := os.ReadFile(path.Join(workingDir, "stderr"))
assert.NoError(t, err, "stderr file should be read")
assert.Contains(t, string(fileInfo), "is not recognized as an internal or external command", "stderr message should be as expected")
}