speculator: Tool to preview spec pull requests

Not the prettiest thing in the world, and horribly unperformant, but
useful :)
pull/977/head
Daniel Wagner-Hall 9 years ago
parent cf3475515e
commit 34091038f3

@ -0,0 +1,4 @@
speculator allows you to preview pull requests to the matrix.org specification.
To run it, you must install the `go` tool, and run:
`go run main.go`

@ -0,0 +1,220 @@
// speculator allows you to preview pull requests to the matrix.org specification.
// It serves two HTTP endpoints:
// - /spec/123 which renders the spec as html at pull request 123.
// - /diff/rst/123 which gives a diff of the spec's rst at pull request 123.
// It is currently woefully inefficient, and there is a lot of low hanging fruit for improvement.
package main
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"io"
"io/ioutil"
"log"
"math/rand"
"net/http"
"os"
"os/exec"
"path"
"strconv"
"strings"
"syscall"
)
type PullRequest struct {
Base Commit
Head Commit
User User
}
type Commit struct {
SHA string
Repo RequestRepo
}
type RequestRepo struct {
CloneURL string `json:"clone_url"`
}
type User struct {
Login string
}
var (
port = flag.Int("port", 9000, "Port on which to listen for HTTP")
allowedMembers map[string]bool
)
func gitClone(url string) (string, error) {
dst := path.Join("/tmp/matrix-doc", strconv.FormatInt(rand.Int63(), 10))
cmd := exec.Command("git", "clone", url, dst)
err := cmd.Run()
if err != nil {
return "", fmt.Errorf("error cloning repo: %v", err)
}
return dst, nil
}
func gitCheckout(path, sha string) error {
cmd := exec.Command("git", "checkout", sha)
cmd.Dir = path
err := cmd.Run()
if err != nil {
return fmt.Errorf("error checking out repo: %v", err)
}
return nil
}
func lookupPullRequest(prNumber string) (PullRequest, error) {
resp, _ := http.Get("https://api.github.com/repos/matrix-org/matrix-doc/pulls/" + prNumber)
defer resp.Body.Close()
dec := json.NewDecoder(resp.Body)
var pr PullRequest
_ = dec.Decode(&pr)
return pr, nil
}
func generate(dir string) error {
cmd := exec.Command("python", "gendoc.py", "--nodelete")
cmd.Dir = path.Join(dir, "scripts")
var b bytes.Buffer
cmd.Stderr = &b
err := cmd.Run()
if err != nil {
return fmt.Errorf("error generating spec: %v\nOutput from gendoc:\n%v", err, b.String())
}
return nil
}
func writeError(w http.ResponseWriter, err error) {
w.WriteHeader(500)
io.WriteString(w, fmt.Sprintf("%v\n", err))
}
// generateAt generates spec from repo at sha.
// Returns the path where the generation was done.
func generateAt(repo, sha string) (dst string, err error) {
dst, err = gitClone(repo)
if err != nil {
return
}
if err = gitCheckout(dst, sha); err != nil {
return
}
err = generate(dst)
return
}
func serveSpec(w http.ResponseWriter, req *http.Request) {
parts := strings.Split(req.URL.Path, "/")
if len(parts) != 3 {
w.WriteHeader(400)
io.WriteString(w, fmt.Sprintf("Invalid path passed: %v expect /pull/123", req.URL.Path))
return
}
pr, err := lookupPullRequest(parts[2])
if err != nil {
writeError(w, err)
return
}
if !allowedMembers[pr.User.Login] {
w.WriteHeader(403)
io.WriteString(w, fmt.Sprintf("%q is not a trusted pull requester", pr.User.Login))
return
}
dst, err := generateAt(pr.Head.Repo.CloneURL, pr.Head.SHA)
defer os.RemoveAll(dst)
if err != nil {
writeError(w, err)
return
}
b, err := ioutil.ReadFile(path.Join(dst, "scripts/gen/specification.html"))
if err != nil {
writeError(w, fmt.Errorf("Error reading spec: %v", err))
return
}
w.Write(b)
}
func serveRstDiff(w http.ResponseWriter, req *http.Request) {
parts := strings.Split(req.URL.Path, "/")
if len(parts) != 4 {
w.WriteHeader(400)
io.WriteString(w, fmt.Sprintf("Invalid path passed: %v expect /diff/rst/123", req.URL.Path))
return
}
pr, err := lookupPullRequest(parts[3])
if err != nil {
writeError(w, err)
return
}
if !allowedMembers[pr.User.Login] {
w.WriteHeader(403)
io.WriteString(w, fmt.Sprintf("%q is not a trusted pull requester", pr.User.Login))
return
}
base, err := generateAt(pr.Base.Repo.CloneURL, pr.Base.SHA)
defer os.RemoveAll(base)
if err != nil {
writeError(w, err)
return
}
head, err := generateAt(pr.Head.Repo.CloneURL, pr.Head.SHA)
defer os.RemoveAll(head)
if err != nil {
writeError(w, err)
return
}
diffCmd := exec.Command("diff", path.Join(base, "scripts", "tmp", "full_spec.rst"), path.Join(head, "scripts", "tmp", "full_spec.rst"))
var diff bytes.Buffer
diffCmd.Stdout = &diff
if err := ignoreExitCodeOne(diffCmd.Run()); err != nil {
writeError(w, fmt.Errorf("error running diff: %v", err))
return
}
w.Write(diff.Bytes())
}
func ignoreExitCodeOne(err error) error {
if err == nil {
return err
}
if exiterr, ok := err.(*exec.ExitError); ok {
if status, ok := exiterr.Sys().(syscall.WaitStatus); ok {
if status.ExitStatus() == 1 {
return nil
}
}
}
return err
}
func main() {
flag.Parse()
// It would be great to read this from github, but there's no convenient way to do so.
// Most of these memberships are "private", so would require some kind of auth.
allowedMembers = map[string]bool{
"dbkr": true,
"erikjohnston": true,
"illicitonion": true,
"Kegsay": true,
"NegativeMjark": true,
}
http.HandleFunc("/spec/", serveSpec)
http.HandleFunc("/diff/rst/", serveRstDiff)
log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", *port), nil))
}
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