Files
storage-appliance/internal/infra/osexec/osexec.go
2025-12-13 15:31:52 +00:00

143 lines
4.1 KiB
Go

package osexec
import (
"context"
"errors"
"fmt"
"os/exec"
"regexp"
"time"
)
// Typed errors
var (
ErrTimeout = errors.New("command timeout")
)
// ErrExitNonZero is returned when a command returned a non-zero exit status.
type ErrExitNonZero struct {
ExitCode int
Stdout string
Stderr string
}
func (e ErrExitNonZero) Error() string {
return fmt.Sprintf("command exit status %d", e.ExitCode)
}
// Runner defines the behavior for executing a command. Implementations can be injected for tests.
type Runner interface {
Run(ctx context.Context, name string, args ...string) (stdout string, stderr string, exitCode int, err error)
}
// DefaultMaxOutputBytes limits stdout/stderr returned by Exec.
const DefaultMaxOutputBytes = 64 * 1024
// DefaultRunner executes real OS commands.
type DefaultRunner struct {
RedactPatterns []*regexp.Regexp
MaxOutputBytes int
}
func NewDefaultRunner(patterns []string) *DefaultRunner {
var compiled []*regexp.Regexp
for _, p := range patterns {
r, err := regexp.Compile(p)
if err == nil {
compiled = append(compiled, r)
}
}
return &DefaultRunner{RedactPatterns: compiled, MaxOutputBytes: DefaultMaxOutputBytes}
}
func (r *DefaultRunner) redact(s string) string {
if len(r.RedactPatterns) == 0 {
return s
}
out := s
for _, re := range r.RedactPatterns {
out = re.ReplaceAllString(out, "[REDACTED]")
}
return out
}
func (r *DefaultRunner) truncate(s string) (string, bool) {
max := r.MaxOutputBytes
if max <= 0 || len(s) <= max {
return s, false
}
return s[:max] + "... (truncated)", true
}
// Run executes a command using os/exec and returns captured output and exit code.
func (r *DefaultRunner) Run(ctx context.Context, name string, args ...string) (string, string, int, error) {
start := time.Now()
// use exec.CommandContext to respect context deadlines
cmd := exec.CommandContext(ctx, name, args...)
outBytes, err := cmd.Output() // only captures stdout; we rely on combined output for simplicity
var stderr []byte
if err != nil {
if ee, ok := err.(*exec.ExitError); ok {
stderr = ee.Stderr
}
}
// If context timed out
if ctx.Err() == context.DeadlineExceeded || ctx.Err() == context.Canceled {
return string(outBytes), string(stderr), -1, ErrTimeout
}
stdout := string(outBytes)
sErrStr := string(stderr)
// Truncate outputs if needed
stdout, _ = r.truncate(stdout)
sErrStr, _ = r.truncate(sErrStr)
// If command failed with non-zero exit
if err != nil {
if exitErr, ok := err.(*exec.ExitError); ok {
code := exitErr.ExitCode()
return stdout, sErrStr, code, ErrExitNonZero{ExitCode: code, Stdout: stdout, Stderr: sErrStr}
}
return stdout, sErrStr, -1, err
}
_ = time.Since(start) // measure duration; can be logged by caller
return stdout, sErrStr, 0, nil
}
// Exec runs using DefaultRunner; default patterns are warmed up empty
var Default = NewDefaultRunner(nil)
// Exec is a convenience function using the Default runner.
func Exec(ctx context.Context, name string, args ...string) (string, string, int, error) {
return Default.Run(ctx, name, args...)
}
// ExecWithRunner uses the provided Runner to execute and normalizes errors.
func ExecWithRunner(r Runner, ctx context.Context, name string, args ...string) (string, string, int, error) {
out, errOut, code, err := r.Run(ctx, name, args...)
// timeout
if ctx.Err() == context.DeadlineExceeded || ctx.Err() == context.Canceled {
return out, errOut, -1, ErrTimeout
}
// runner returned an error
if err != nil {
// If error implements ErrExitNonZero (already constructed by runner), return as is
var exitErr ErrExitNonZero
if errors.As(err, &exitErr) {
return exitErr.Stdout, exitErr.Stderr, exitErr.ExitCode, exitErr
}
// If it's an exec.ExitError, wrap in ErrExitNonZero
var execExit *exec.ExitError
if errors.As(err, &execExit) {
return out, errOut, execExit.ExitCode(), ErrExitNonZero{ExitCode: execExit.ExitCode(), Stdout: out, Stderr: errOut}
}
return out, errOut, code, err
}
// no error, but a non-zero exit code
if code != 0 {
return out, errOut, code, ErrExitNonZero{ExitCode: code, Stdout: out, Stderr: errOut}
}
return out, errOut, code, nil
}