feat: initial commit of vps-commander release v1.0.0

internal/executor/executor.go

@@ -0,0 +1,79 @@
+package executor
+
+import (
+	"bytes"
+	"context"
+	"os/exec"
+	"strings"
+	"syscall"
+	"time"
+)
+
+type Result struct {
+	ExitCode   int
+	Stdout     string
+	Stderr     string
+	DurationMS int64
+}
+
+type Local struct{ MaxOutput int }
+
+type cappedBuffer struct {
+	buf bytes.Buffer
+	max int
+}
+
+func (b *cappedBuffer) Write(p []byte) (int, error) {
+	if b.max <= 0 {
+		return len(p), nil
+	}
+	if b.buf.Len() < b.max {
+		n := b.max - b.buf.Len()
+		if n > len(p) {
+			n = len(p)
+		}
+		_, _ = b.buf.Write(p[:n])
+	}
+	return len(p), nil
+}
+
+func (e Local) Run(ctx context.Context, command, workdir string) Result {
+	start := time.Now()
+	if e.MaxOutput <= 0 {
+		e.MaxOutput = 1024 * 1024
+	}
+	cmd := exec.Command("/bin/sh", "-c", command)
+	cmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}
+	if workdir != "" {
+		cmd.Dir = workdir
+	}
+	var stdout, stderr cappedBuffer
+	stdout.max, stderr.max = e.MaxOutput, e.MaxOutput
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+	if err := cmd.Start(); err != nil {
+		return Result{ExitCode: 1, Stderr: err.Error(), DurationMS: time.Since(start).Milliseconds()}
+	}
+	waitCh := make(chan error, 1)
+	go func() { waitCh <- cmd.Wait() }()
+	timedOut := false
+	var err error
+	select {
+	case err = <-waitCh:
+	case <-ctx.Done():
+		timedOut = true
+		_ = syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL)
+		err = <-waitCh
+	}
+	code := 0
+	if err != nil {
+		code = 1
+		if ee, ok := err.(*exec.ExitError); ok {
+			code = ee.ExitCode()
+		}
+	}
+	if timedOut || ctx.Err() != nil {
+		code = 124
+	}
+	return Result{code, stdout.buf.String(), strings.TrimSpace(stderr.buf.String()), time.Since(start).Milliseconds()}
+}