Signature V4 requires AWS credentials for request signing when using MinIO with objectfs

[MohammadTaghipour]

When configuring Moodle with the tool_objectfs plugin to use MinIO (S3-compatible storage), the following error occurs:

Exception - Could not resolve an authentication scheme: Signature V4 requires AWS credentials for request signing

Expected behavior
The plugin should connect successfully to MinIO using the provided S3 credentials (Access key / Secret key).

Actual behavior
Connection fails with the exception above, as if no AWS credentials were being passed to the request signer.

Environment

Moodle version: 5.0.2

tool_objectfs version: 2025040900

Deployment: Docker

Additional context

Using Moodle version 4.3 works fine but was not working with 5.0.2 and 4.5.

All plugins are updated to the latest version.

[MohammadTaghipour]

Here is my setup:

docker-compose.yml

services:
  moodle:
    image: bitnami/moodle:latest
    container_name: moodle
    ports:
      - "9090:8080"
    environment:
      - MOODLE_DATABASE_TYPE=pgsql
      - MOODLE_DATABASE_HOST=postgres
      - MOODLE_DATABASE_PORT_NUMBER=5432
      - MOODLE_DATABASE_USER=moodle
      - MOODLE_DATABASE_PASSWORD=moodlepass
      - MOODLE_DATABASE_NAME=moodle
      - MOODLE_USERNAME=admin
      - MOODLE_PASSWORD=adminpass
      - MOODLE_EMAIL=admin@example.com
    depends_on:
      - postgres
      - minio
    volumes:
      - moodle_data:/bitnami/moodle
    networks:
      moodle-net:
        aliases:
          - mymoodle.minio

  postgres:
    image: postgres:15
    container_name: postgres
    environment:
      - POSTGRES_USER=moodle
      - POSTGRES_PASSWORD=moodlepass
      - POSTGRES_DB=moodle
    ports:
      - "5431:5432"
    volumes:
      - postgres_data:/var/lib/postgresql/data
    networks:
      - moodle-net

  minio:
    image: minio/minio:latest
    container_name: minio
    command: server /data --console-address ":9001"
    ports:
      - "9000:9000"   
      - "9001:9001"  
    environment:
      - MINIO_ROOT_USER=admin
      - MINIO_ROOT_PASSWORD=adminpass
      - MINIO_DOMAIN=minio
    volumes:
      - minio_data:/data
    networks:
      moodle-net:
        aliases:
          - mymoodle.minio

volumes:
  moodle_data:
  postgres_data:
  minio_data:

networks:
  moodle-net:
    driver: bridge

Config.php

<?php  // Moodle configuration file

unset($CFG);
global $CFG;
$CFG = new stdClass();

$CFG->dbtype    = 'pgsql';
$CFG->dblibrary = 'native';
$CFG->dbhost    = 'postgres';
$CFG->dbname    = 'moodle';
$CFG->dbuser    = 'moodle';
$CFG->dbpass    = 'moodlepass';
$CFG->prefix    = 'mdl_';
$CFG->dboptions = array (
  'dbpersist' => 0,
  'dbport' => 5432,
  'dbsocket' => '',
);

if (empty($_SERVER['HTTP_HOST'])) {
  $_SERVER['HTTP_HOST'] = '127.0.0.1:8080';
}
if (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on') {
  $CFG->wwwroot   = 'https://' . $_SERVER['HTTP_HOST'];
} else {
  $CFG->wwwroot   = 'http://' . $_SERVER['HTTP_HOST'];
}
$CFG->dataroot  = '/bitnami/moodledata';
$CFG->admin     = 'admin';

$CFG->directorypermissions = 02775;

$CFG->alternative_file_system_class = '\tool_objectfs\s3_file_system';

require_once(__DIR__ . '/lib/setup.php');

// There is no php closing tag in this file,
// it is intentional because it prevents trailing whitespace problems!

Also the objectfs config is: