Bring back update-contributors but in go (#3512)

I think it is a nice to have this appreciation, but we haven't updated
in a while, as the nodejs of the old tools no longer maintained.

Just threw some go together quickly.

.github/workflows/update-contributors.yml

@@ -0,0 +1,29 @@
+name: Update Contributors in README
+
+on:
+  push:
+    branches: [main]
+
+jobs:
+  update-contributors:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: '1.22'
+      - name: Update contributors
+        run: make update-contributors
+
+      - uses: stefanzweifel/git-auto-commit-action@v5
+        with:
+          # these are credentials for https://github.com/pyroscopebot
+          token: ${{ secrets.BOT_GITHUB_TOKEN }}
+          commit_user_name: Pyroscope Bot
+          commit_user_email: dmitry+bot@pyroscope.io
+          commit_author: 'Pyroscope Bot <dmitry+bot@pyroscope.io>'
+          commit_message: 'docs: updates the list of contributors in README'
+          file_pattern: README.md
+        env:
+          GITHUB_TOKEN: ${{ secrets.BOT_GITHUB_TOKEN }}

Makefile

@@ -146,6 +146,10 @@ go/lint: $(BIN)/golangci-lint
 	$(BIN)/golangci-lint run
 	$(GO) vet ./...
 
+.PHONY: update-contributors
+update-contributors: ## Update the contributors in README.md
+	go run ./tools/update-contributors
+
 .PHONY: go/mod
 go/mod: $(foreach P,$(GO_MOD_PATHS),go/mod_tidy/$P)
 

tools/update-contributors/main.go

@@ -0,0 +1,136 @@
+package main
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"log"
+	"net/http"
+	"os"
+	"strings"
+)
+
+type contributor struct {
+	Login     string `json:"login"`
+	AvatarURL string `json:"avatar_url"`
+	HTMLURL   string `json:"html_url"`
+}
+
+func fetchContributors(ctx context.Context, owner, repo string) ([]contributor, error) {
+	url := fmt.Sprintf("https://api.github.com/repos/%s/%s/contributors?per_page=200", owner, repo)
+	req, err := http.NewRequest("GET", url, nil)
+	if err != nil {
+		return nil, err
+	}
+	req = req.WithContext(ctx)
+
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, fmt.Errorf("unexpected status code %d", resp.StatusCode)
+	}
+
+	var contributors []contributor
+	if err := json.NewDecoder(resp.Body).Decode(&contributors); err != nil {
+		return nil, err
+	}
+
+	return contributors, nil
+}
+
+func generateContributors() (string, error) {
+	ctx := context.Background()
+	contributors, err := fetchContributors(ctx, "grafana", "pyroscope")
+	if err != nil {
+		return "", err
+	}
+
+	sb := strings.Builder{}
+
+	limit := 9 * 7
+
+	for _, c := range contributors {
+		// filter bots
+		if strings.HasSuffix(c.Login, "[bot]") || c.Login == "pyroscopebot" {
+			continue
+		}
+		sb.WriteString(`<a href="`)
+		sb.WriteString(c.HTMLURL)
+		sb.WriteString(`"><img src="`)
+		sb.WriteString(c.AvatarURL)
+		sb.WriteString(`" title="`)
+		sb.WriteString(c.Login)
+		sb.WriteString(`" width="80" height="80"></a>`)
+		sb.WriteByte('\n')
+		limit--
+		if limit == 0 {
+			break
+		}
+	}
+
+	return sb.String(), nil
+}
+
+const (
+	marker     = "[//]: contributor-faces"
+	readmeFile = "README.md"
+)
+
+func replaceReadme() error {
+	b, err := os.ReadFile(readmeFile)
+	if err != nil {
+		return err
+	}
+	s := string(b)
+
+	start := strings.Index(s, marker)
+	if start == -1 {
+		return fmt.Errorf("could not find marker %q", marker)
+	}
+	start += len(marker) + 1
+
+	end := strings.Index(s[start:], marker)
+	if end == -1 {
+		return fmt.Errorf("could not find end marker %q", marker)
+	}
+	end += start
+
+	contributor, err := generateContributors()
+	if err != nil {
+		return err
+	}
+
+	f, err := os.Create(readmeFile)
+	if err != nil {
+		return err
+	}
+
+	defer f.Close()
+
+	_, err = f.WriteString(s[:start])
+	if err != nil {
+		return err
+	}
+
+	_, err = f.WriteString(contributor)
+	if err != nil {
+		return err
+	}
+
+	_, err = f.WriteString(s[end:])
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func main() {
+	if err := replaceReadme(); err != nil {
+		log.Fatal(err)
+	}
+}