forgejo/modules/markup/external/external.go
zeripath 302e8b6d02
Prevent zombie processes (#16314)
Unfortunately go doesn't always ensure that execd processes are completely
waited for. On linux this means that zombie processes can occur.

This PR ensures that these are waited for by using signal notifier in serv and
passing a context elsewhere.

Signed-off-by: Andrew Thornton <art27@cantab.net>
2021-06-30 22:07:23 +02:00

122 lines
3.2 KiB
Go

// Copyright 2017 The Gitea Authors. All rights reserved.
// Use of this source code is governed by a MIT-style
// license that can be found in the LICENSE file.
package external
import (
"context"
"fmt"
"io"
"io/ioutil"
"os"
"os/exec"
"runtime"
"strings"
"code.gitea.io/gitea/modules/log"
"code.gitea.io/gitea/modules/markup"
"code.gitea.io/gitea/modules/process"
"code.gitea.io/gitea/modules/setting"
"code.gitea.io/gitea/modules/util"
)
// RegisterRenderers registers all supported third part renderers according settings
func RegisterRenderers() {
for _, renderer := range setting.ExternalMarkupRenderers {
if renderer.Enabled && renderer.Command != "" && len(renderer.FileExtensions) > 0 {
markup.RegisterRenderer(&Renderer{renderer})
}
}
}
// Renderer implements markup.Renderer for external tools
type Renderer struct {
*setting.MarkupRenderer
}
// Name returns the external tool name
func (p *Renderer) Name() string {
return p.MarkupName
}
// NeedPostProcess implements markup.Renderer
func (p *Renderer) NeedPostProcess() bool {
return p.MarkupRenderer.NeedPostProcess
}
// Extensions returns the supported extensions of the tool
func (p *Renderer) Extensions() []string {
return p.FileExtensions
}
// SanitizerRules implements markup.Renderer
func (p *Renderer) SanitizerRules() []setting.MarkupSanitizerRule {
return p.MarkupSanitizerRules
}
func envMark(envName string) string {
if runtime.GOOS == "windows" {
return "%" + envName + "%"
}
return "$" + envName
}
// Render renders the data of the document to HTML via the external tool.
func (p *Renderer) Render(ctx *markup.RenderContext, input io.Reader, output io.Writer) error {
var (
urlRawPrefix = strings.Replace(ctx.URLPrefix, "/src/", "/raw/", 1)
command = strings.NewReplacer(envMark("GITEA_PREFIX_SRC"), ctx.URLPrefix,
envMark("GITEA_PREFIX_RAW"), urlRawPrefix).Replace(p.Command)
commands = strings.Fields(command)
args = commands[1:]
)
if p.IsInputFile {
// write to temp file
f, err := ioutil.TempFile("", "gitea_input")
if err != nil {
return fmt.Errorf("%s create temp file when rendering %s failed: %v", p.Name(), p.Command, err)
}
tmpPath := f.Name()
defer func() {
if err := util.Remove(tmpPath); err != nil {
log.Warn("Unable to remove temporary file: %s: Error: %v", tmpPath, err)
}
}()
_, err = io.Copy(f, input)
if err != nil {
f.Close()
return fmt.Errorf("%s write data to temp file when rendering %s failed: %v", p.Name(), p.Command, err)
}
err = f.Close()
if err != nil {
return fmt.Errorf("%s close temp file when rendering %s failed: %v", p.Name(), p.Command, err)
}
args = append(args, f.Name())
}
processCtx, cancel := context.WithCancel(ctx.Ctx)
defer cancel()
pid := process.GetManager().Add(fmt.Sprintf("Render [%s] for %s", commands[0], ctx.URLPrefix), cancel)
defer process.GetManager().Remove(pid)
cmd := exec.CommandContext(processCtx, commands[0], args...)
cmd.Env = append(
os.Environ(),
"GITEA_PREFIX_SRC="+ctx.URLPrefix,
"GITEA_PREFIX_RAW="+urlRawPrefix,
)
if !p.IsInputFile {
cmd.Stdin = input
}
cmd.Stdout = output
if err := cmd.Run(); err != nil {
return fmt.Errorf("%s render run command %s %v failed: %v", p.Name(), commands[0], args, err)
}
return nil
}