// Copyright 2019-2020 Google LLC.
// SPDX-License-Identifier: Apache-2.0
//
// besadii is a small CLI tool that runs as a Gerrit hook (currently
// 'ref-updated') to trigger various actions:
//
// - sr.ht CI builds
// - SourceGraph (cs.tvl.fyi) repository index updates
package main
import (
"bytes"
"encoding/json"
"flag"
"fmt"
"io/ioutil"
"log/syslog"
"net/http"
"os"
"path"
"strings"
)
var branchPrefix = "refs/heads/"
// Represents an updated branch, as passed to besadii by Gerrit.
//
// https://gerrit.googlesource.com/plugins/hooks/+/HEAD/src/main/resources/Documentation/hooks.md#ref_updated
type branchUpdate struct {
project string
branch string
commit string
submitter string
}
// Represents a builds.sr.ht build object as described on
// https://man.sr.ht/builds.sr.ht/api.md
type Build struct {
Manifest string `json:"manifest"`
Note string `json:"note"`
Tags []string `json:"tags"`
}
// Represents a build trigger object as described on
// https://man.sr.ht/builds.sr.ht/triggers.md
type Trigger struct {
Action string `json:"action"`
Condition string `json:"condition"`
To string `json:"to"`
}
// Represents a build manifest for sourcehut.
type Manifest struct {
Image string `json:"image"`
Sources []string `json:"sources"`
Secrets []string `json:"secrets"`
Tasks [](map[string]string) `json:"tasks"`
Triggers []Trigger `json:"triggers"`
}
func prepareManifest(commit string) string {
m := Manifest{
Image: "nixos/latest",
Sources: []string{"https://code.tvl.fyi/"},
// secret for cachix/tazjin
Secrets: []string{"f7f02546-4d95-44f7-a98e-d61fdded8b5b"},
Tasks: [](map[string]string){
{"setup": `# sourcehut does not censor secrets in builds, hence this hack:
echo -n 'export CACHIX_SIGNING_KEY=' >> ~/.buildenv
cat ~/.cachix-tazjin >> ~/.buildenv
nix-env -iA third_party.cachix -f code.tvl.fyi
cachix use tazjin
cd code.tvl.fyi
git checkout ` + commit},
{"build": `cd code.tvl.fyi
nix-build ci-builds.nix > built-paths`},
{"cache": `cd code.tvl.fyi
cat built-paths | cachix push tazjin`},
},
Triggers: []Trigger{
Trigger{Action: "email", Condition: "failure", To: "mail@tazj.in"},
},
}
j, _ := json.Marshal(m)
return string(j)
}
// Trigger a build of a given branch & commit on builds.sr.ht
func triggerBuild(log *syslog.Writer, token string, update *branchUpdate) error {
build := Build{
Manifest: prepareManifest(update.commit),
Note: fmt.Sprintf("build of %q at %q, submitted by %q", update.branch, update.commit, update.submitter),
Tags: []string{
// my branch names tend to contain slashes, which are not valid
// identifiers in sourcehut.
"depot", strings.ReplaceAll(update.branch, "/", "_"),
},
}
body, _ := json.Marshal(build)
reader := ioutil.NopCloser(bytes.NewReader(body))
req, err := http.NewRequest("POST", "https://builds.sr.ht/api/jobs", reader)
if err != nil {
return fmt.Errorf("failed to create an HTTP request: %w", err)
}
req.Header.Add("Authorization", "token "+token)
req.Header.Add("Content-Type", "application/json")
resp, err := http.DefaultClient.Do(req)
if err != nil {
// This might indicate a temporary error on the sourcehut side.
return fmt.Errorf("failed to send builds.sr.ht request: %w", err)
}
defer resp.Body.Close()
if resp.StatusCode != 200 {
respBody, _ := ioutil.ReadAll(resp.Body)
log.Err(fmt.Sprintf("received non-success response from builds.sr.ht: %s (%v)", respBody, resp.Status))
} else {
fmt.Fprintf(log, "triggered builds.sr.ht job for branch %q at commit %q", update.branch, update.commit)
}
return nil
}
// Trigger a Sourcegraph repository index update on cs.tvl.fyi.
//
// https://docs.sourcegraph.com/admin/repo/webhooks
func triggerIndexUpdate(token string) error {
req, err := http.NewRequest("POST", "https://cs.tvl.fyi/.api/repos/depot/-/refresh", nil)
if err != nil {
return err
}
req.Header.Add("Authorization", "token "+token)
_, err = http.DefaultClient.Do(req)
return err
}
func branchUpdateFromFlags() (*branchUpdate, error) {
if path.Base(os.Args[0]) != "ref-updated" {
return nil, fmt.Errorf("besadii must be invoked as the 'ref-updated' hook")
}
var update branchUpdate
flag.StringVar(&update.project, "project", "", "Gerrit project")
flag.StringVar(&update.commit, "newrev", "", "new revision")
flag.StringVar(&update.submitter, "submitter-username", "", "Submitter username")
ref := flag.String("refname", "", "updated reference name")
// Gerrit passes more flags than we want, but Rob Pike decided[0] in
// 2013 that the Go art project will not allow users to ignore flags
// because he "doesn't like it". The following code ignores the
// flags.
//
// [0]: https://github.com/golang/go/issues/6112#issuecomment-66083768
var _old, _submitter string
flag.StringVar(&_old, "oldrev", "", "")
flag.StringVar(&_submitter, "submitter", "", "")
flag.Parse()
if update.project == "" || *ref == "" || update.commit == "" || update.submitter == "" {
// If we get here, the user is probably being a dummy and invoking
// this manually - but incorrectly.
return nil, fmt.Errorf("'ref-updated' hook invoked without required arguments")
}
if update.project != "depot" {
// this is not an error, but also not something we handle.
return nil, nil
}
if !strings.HasPrefix(*ref, branchPrefix) {
return nil, fmt.Errorf("besadii only supports branch updates at the moment")
}
update.branch = strings.TrimPrefix(*ref, branchPrefix)
return &update, nil
}
func main() {
log, err := syslog.New(syslog.LOG_INFO|syslog.LOG_USER, "besadii")
if err != nil {
fmt.Printf("failed to open syslog: %s\n", err)
os.Exit(1)
}
srhtToken, err := ioutil.ReadFile("/etc/secrets/srht-token")
if err != nil {
log.Alert("sourcehut token could not be read")
os.Exit(1)
}
sourcegraphToken, err := ioutil.ReadFile("/etc/secrets/sourcegraph-token")
if err != nil {
log.Alert("sourcegraph token could not be read")
os.Exit(1)
}
update, err := branchUpdateFromFlags()
if err != nil {
log.Err(fmt.Sprintf("failed to parse ref update: %s", err))
os.Exit(1)
}
if update == nil { // the project was not 'depot'
os.Exit(0)
}
err = triggerBuild(log, string(srhtToken), update)
if err != nil {
log.Err(fmt.Sprintf("failed to trigger sr.ht build: %s", err))
}
err = triggerIndexUpdate(string(sourcegraphToken))
if err != nil {
log.Err(fmt.Sprintf("failed to trigger sourcegraph index update: %s", err))
}
}
