feat(ops/besadii): Refactored tool to trigger sourcehut builds

Refactors //ops/sync-gcsr which was previously responsible for
synchronising the git repository between GCSR and the git.tazj.in cgit
instance to simply be responsible for triggering builds on sourcehut.

This program is intended to run as a git post-update hook.

Note: Not yet feature complete, as interpolation of concrete git
values and also sourcehut secrets is missing.

2 files changed, 127 insertions, 0 deletions

diff --git a/ops/besadii/default.nix b/ops/besadii/default.nix
new file mode 100644
index 000000000000..fc7b2286c7ee
--- /dev/null
+++ b/ops/besadii/default.nix
@@ -0,0 +1,8 @@
+# This program is used as a git post-update hook to trigger builds on
+# sourcehut.
+{ depot, ... }:
+
+depot.buildGo.program {
+  name = "besadii";
+  srcs = [ ./main.go ];
+}
diff --git a/ops/besadii/main.go b/ops/besadii/main.go
new file mode 100644
index 000000000000..e9feadd9538e
--- /dev/null
+++ b/ops/besadii/main.go
@@ -0,0 +1,119 @@
+// Copyright 2019 Google LLC.
+// SPDX-License-Identifier: Apache-2.0
+//
+// besadii is a small CLI tool that triggers depot builds on
+// builds.sr.ht
+//
+// It is designed to run as a post-update git hook on the server
+// hosting the depot.
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io/ioutil"
+	"log"
+	"net/http"
+	"os"
+)
+
+// 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 <the docs for
+// this are currently down>
+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://git.camden.tazj.in/"},
+
+		// 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 git.tazj.in
+cachix use tazjin
+cd git.tazj.in
+git checkout ` + commit},
+
+			{"build": `cd git.tazj.in
+nix-build ci-builds.nix > built-paths`},
+
+			{"cache": `cd git.tazj.in
+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(branch, commit string) {
+	build := Build{
+		Manifest: prepareManifest(commit),
+		Note:     fmt.Sprintf("Build of 'master' at '%s'", commit),
+		Tags: []string{
+			"depot", 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 {
+		log.Fatalln("[ERROR] failed to create an HTTP request:", err)
+	}
+
+	req.Header.Add("Authorization", fmt.Sprintf("token %s", os.Getenv("SRHT_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, do
+		// not fail the whole program.
+		log.Println("failed to send builds.sr.ht request:", err)
+		return
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != 200 {
+		respBody, err := ioutil.ReadAll(resp.Body)
+		log.Printf("received non-success response from builds.sr.ht: %s (%v)[%s]", respBody, resp.Status, err)
+	} else {
+		log.Println("triggered builds.sr.ht job for commit", commit)
+	}
+}
+
+func main() {
+	triggerBuild("master", "c5806a44a728d5a46878f54de7b695321a38559c")
+}