uboto3

uboto3 is a MicroPython library designed to facilitate uploading files directly from a MicroPython-enabled device (like an ESP32 or ESP8266) to Amazon Web Services (AWS) S3 or to a S3-compatible provider. 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.

Features

• Direct S3 Upload: Upload files directly to an S3 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 AWS request signing.
• Minimal Dependencies: Built with standard MicroPython libraries like urequests, uhashlib, ubinascii, utime, and network.

Requirements

• 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)

Setup

1. Copy uboto3.py: Create a uboto3 directory file into the the /lib directory of your MicroPython device and copy the __init__.py file into it.

2. AWS Credentials & Configuration: Import the S3Client class from uboto3 and set your AWS credentials and S3 bucket details in your script:

   from uboto3 import S3Client
   # --- AWS Configuration ---
   PROVIDER = "amazonaws.com" # or "backblazeb2.com" or other S3 compatible provider
   AWS_ACCESS_KEY = "YOUR_AWS_ACCESS_KEY_ID"  
   AWS_SECRET_KEY = "YOUR_AWS_SECRET_ACCESS_KEY"
   AWS_REGION = "your-s3-bucket-region" 
   
   client = S3Client(
       provider=PROVIDER,
       access_key=AWS_ACCESS_KEY,
       secret_key=AWS_SECRET_KEY,
       region=AWS_REGION,
   )
   

   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 AWS IAM user associated with the AWS_ACCESS_KEY and AWS_SECRET_KEY has the necessary permissions to put objects into the specified S3 bucket. A minimal policy would look like this:

   {
       "Version": "2012-10-17",
       "Statement": [
           {
               "Effect": "Allow",
               "Action": [
                   "s3:PutObject"
               ],
               "Resource": [
                   "arn:aws:s3:::your-s3-bucket-name/*"
               ]
           }
       ]
   }
   

   Replace "your-s3-bucket-name" with your actual bucket name.

Usage Example

Here's how to use uboto3 to upload a local file from your MicroPython device to S3:

import network
import time
from uboto3 import S3Client
# --- 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())

PROVIDER = "amazonaws.com" # or "backblazeb2.com" or other S3 compatible provider
AWS_ACCESS_KEY = "YOUR_AWS_ACCESS_KEY_ID"  
AWS_SECRET_KEY = "YOUR_AWS_SECRET_ACCESS_KEY"
AWS_REGION = "your-s3-bucket-region" 

client = S3Client(
    provider=PROVIDER,
    access_key=AWS_ACCESS_KEY,
    secret_key=AWS_SECRET_KEY,
    region=AWS_REGION,
)

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

    # 2. Synchronize time (critical for AWS authentication)
    client.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 S3
    s3_object_name = "my_device_data/data.txt" # Desired path and name in S3
    content_type = "bucket_nametext/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 S3 bucket '{bucket_name}' as '{s3_object_name}'...")
    if client.upload_to_s3(local_file_to_upload, bucket_name, s3_object_name, content_type):
        print("Upload successful!")
    else:
        print("Upload failed.")

if __name__ == "__main__":
    main()

Contributing

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

License

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