This Pocketbase hook demonstrates how to fetch a Gravatar image for a user's email and save it to the filesystem after user creation. If the associated email has no Gravatar image, the hook will do nothing.

pocketbase-gravatar-hook.go

package main

import (
	"crypto/sha256"
	"encoding/hex"
	"fmt"
	"io"
	"net/http"
	"os"
	"path/filepath"

	"github.com/pocketbase/pocketbase"
	"github.com/pocketbase/pocketbase/core"
	"github.com/pocketbase/pocketbase/tools/filesystem"
)

func main() {
	app := pocketbase.New()

	app.OnRecordAfterCreateRequest("users").Add(func(event *core.RecordCreateEvent) error {
		user := event.Record

		// Generate SHA256 hash of the user's email for Gravatar URL
		email := user.GetString("email")
		emailHash := sha256.New()
		emailHash.Write([]byte(email))
		emailHashHex := hex.EncodeToString(emailHash.Sum(nil))
		gravatarUrl := fmt.Sprintf("https://gravatar.com/avatar/%s?s=512&d=404", emailHashHex)

		// Retrieve the image from Gravatar
		resp, err := http.Get(gravatarUrl)
		if err != nil {
			fmt.Printf("Warning: failed to fetch gravatar for email %s: %v\n", email, err)
			return nil
		}
		defer resp.Body.Close()

		if resp.StatusCode != http.StatusOK {
			fmt.Printf("no Gravatar found for email: %s", email)
			return nil
		}

		// Read the image data
		fileData, err := io.ReadAll(resp.Body)
		if err != nil {
			return fmt.Errorf("failed to read gravatar image: %v", err)
		}

		// Define the file path
		baseFilesPath := user.BaseFilesPath()
		fileName := "avatar.jpg" // You can change this to dynamic file names if needed
		filePath := filepath.Join(baseFilesPath, fileName)

		// Save the image to the filesystem
		fs, err := app.NewFilesystem()
		if err != nil {
			return fmt.Errorf("failed to create filesystem")
		}
		newFile, err := filesystem.NewFileFromBytes(fileData, fileName)
		if err != nil {
			return fmt.Errorf("failed to create fileFromBytes")
		}
		if err := fs.UploadFile(newFile, filePath); err != nil {
			return fmt.Errorf("failed to upload file: %v", err)
		}

		// Update the user record with the avatar file name
		user.Set("avatar", fileName)

		// Save the updated user record
		if err := app.Dao().SaveRecord(user); err != nil {
			return fmt.Errorf("failed to save user record: %v", err)
		}

		return nil
	})

	if err := app.Start(); err != nil {
		fmt.Println("Error starting PocketBase server:", err)
		os.Exit(1)
	}
}