| // Copyright 2019 The Fuchsia Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Package runner provides implementations for running commands in different environments. |
| package runner |
| |
| import ( |
| "context" |
| "io" |
| "os/exec" |
| "syscall" |
| |
| "go.fuchsia.dev/tools/logger" |
| ) |
| |
| // SubprocessRunner is a Runner that runs commands as local subprocesses. |
| type SubprocessRunner struct { |
| // Dir is the working directory of the subprocesses; if unspecified, that |
| // of the current process will be used. |
| Dir string |
| |
| // Env is the environment of the subprocess, following the usual convention of a list of |
| // strings of the form "<environment variable name>=<value>". |
| Env []string |
| } |
| |
| // Run runs a command until completion or until a context is canceled, in |
| // which case the subprocess is killed so that no subprocesses it spun up are |
| // orphaned. |
| func (r *SubprocessRunner) Run(ctx context.Context, command []string, stdout io.Writer, stderr io.Writer) error { |
| cmd := exec.Cmd{ |
| Path: command[0], |
| Args: command, |
| Stdout: stdout, |
| Stderr: stderr, |
| Dir: r.Dir, |
| Env: r.Env, |
| SysProcAttr: &syscall.SysProcAttr{Setpgid: true}, |
| } |
| logger.Infof(ctx, "environment of subprocess:\n%v", cmd.Env) |
| logger.Infof(ctx, "starting:\n%v", cmd.Args) |
| if err := cmd.Start(); err != nil { |
| return err |
| } |
| done := make(chan error) |
| go func() { |
| done <- cmd.Wait() |
| }() |
| select { |
| case err := <-done: |
| return err |
| case <-ctx.Done(): |
| syscall.Kill(-cmd.Process.Pid, syscall.SIGKILL) |
| return ctx.Err() |
| } |
| } |