uminio is a MicroPython library designed to facilitate uploading files directly from a MicroPython-enabled device (like an ESP32 or ESP8266) to MinIO object storage. It implements the necessary AWS Signature Version 4 for an S3 PUT Object request. This allows you to store data, sensor readings, images, or any other files from your microcontroller projects in the cloud.

Forked from uboto3 https://github.com/DanielMilstein/uboto3

• Direct S3 Upload: Upload files directly to an MinIO bucket without needing an intermediary server.
• AWS Signature V4: Implements the required request signing process.
• HMAC-SHA256: Includes a MicroPython-compatible HMAC-SHA256 implementation for signing.
• Time Synchronization: Includes a helper function to synchronize the device's time using NTP, which is crucial for MinIO request signing.
• Minimal Dependencies: Built with standard MicroPython libraries like urequests, uhashlib, ubinascii, utime, and network.

• MicroPython firmware flashed on your device.
• Network connectivity (WiFi) configured on the device.
• The following MicroPython libraries:
  • urequests
  • uhashlib
  • ubinascii
  • utime
  • network
  • ntptime (for time synchronization)

1. Copy __init__.py: Create a uminio folder in the /lib directory of your MicroPython device and copy the __init__.py file into it.

2. MinIO Credentials & Configuration: Import the MinioClient class in your MicroPython script and configure it with your MinIO server details. You can do this by setting the following variables in your script:

   from uminio import MinioClient
   # --- MinIO Client Configuration ---
   MINIO_ENDPOINT = "192.168.1.100:9000"  # Your MinIO server IP address and port
   MINIO_ACCESS_KEY = "YOUR_ACCESS_KEY"      # Your MinIO access key
   MINIO_SECRET_KEY = "YOUR_SECRET_KEY"      # Your MinIO secret key
   MINIO_REGION = "eu-east-1"                # The region for your MinIO server
   MINIO_USE_HTTPS = False               # Set to True if your MinIO server uses HTTPS
   
   mc = MinioClient(
       endpoint=MINIO_ENDPOINT,
       access_key=MINIO_ACCESS_KEY,
       secret_key=MINIO_SECRET_KEY,
       region=MINIO_REGION,
       use_https=MINIO_USE_HTTPS,
   )

   Important Security Note: Hardcoding credentials directly into the script is generally not recommended for production environments. Consider alternative methods for managing secrets on your device if security is a major concern.

3. IAM Permissions: Ensure the MinIO user associated with the MINIO_ACCESS_KEY and MINIO_SECRET_KEY has the necessary permissions to put objects into the specified bucket.

Here's how to use uminio to upload a local file from your MicroPython device to MinIO:

import network
import time
from uminio import MinioClient
# --- MinIO Client Configuration ---
MINIO_ENDPOINT = "192.168.1.100:9000"  # Your MinIO server IP address and port
MINIO_ACCESS_KEY = "YOUR_ACCESS_KEY"      # Your MinIO access key
MINIO_SECRET_KEY = "YOUR_SECRET_KEY"      # Your MinIO secret key
MINIO_REGION = "eu-east-1"                # The region for your MinIO server
MINIO_USE_HTTPS = False               # Set to True if your MinIO server uses HTTPS

mc = MinioClient(
    endpoint=MINIO_ENDPOINT,
    access_key=MINIO_ACCESS_KEY,
    secret_key=MINIO_SECRET_KEY,
    region=MINIO_REGION,
    use_https=MINIO_USE_HTTPS,
)
# --- Network Configuration (Example for ESP32/ESP8266) ---
WIFI_SSID = "YOUR_WIFI_SSID"
WIFI_PASSWORD = "YOUR_WIFI_PASSWORD"

def connect_wifi():
    sta_if = network.WLAN(network.STA_IF) #
    if not sta_if.isconnected():
        print("Connecting to WiFi...")
        sta_if.active(True)
        sta_if.connect(WIFI_SSID, WIFI_PASSWORD)
        while not sta_if.isconnected():
            time.sleep(1)
    print("Network Config:", sta_if.ifconfig())

# --- Main Application ---
def main():
    # 1. Connect to WiFi
    connect_wifi()

    # 2. Synchronize time (critical for MinIO authentication)
    mc.sync_time() #

    # 3. Create a dummy file to upload (or use an existing file)
    local_file_to_upload = "data.txt"
    bucket_name = "my_bucket" # Ensure this bucket exists in MinIO
    s3_object_name = "my_device_data/data.txt" # Desired path and name in S3
    content_type = "text/plain" #

    try:
        with open(local_file_to_upload, "w") as f:
            f.write("Hello from MicroPython!\n")
            f.write(f"Timestamp: {time.time()}\n")
        print(f"Created dummy file: {local_file_to_upload}")
    except OSError as e:
        print(f"Error creating file: {e}")
        return

    # 4. Upload the file
    print(f"Attempting to upload '{local_file_to_upload}' to MinIO bucket '{bucket_name}' as '{s3_object_name}'...")
    if mc.upload_file(local_file_to_upload, bucket_name, s3_object_name, content_type): #
        print("Upload successful!")
    else:
        print("Upload failed.")

if __name__ == "__main__":
    main()

Feel free to fork this repository, submit issues, and create pull requests if you have improvements or bug fixes.

This project is licensed under the MIT License - see the LICENSE file for details.