Overview

EdgeFlow supports Over-the-Air (OTA) firmware updates from the cloud. Firmware binaries are uploaded to S3-compatible storage (MinIO/AWS S3), verified with SHA256 checksums, and distributed to devices via time-limited presigned URLs. Updates can target individual devices or entire fleets using rolling and canary strategies.

Update Flow

Cloud                                    Device
  │                                         │
  │  1. Upload firmware binary to S3        │
  │  (SHA256 checksum verification)         │
  │                                         │
  │  2. Initiate OTA update                 │
  │  (target device or fleet)               │
  │                                         │
  │  3. Send update command via tunnel      │
  │────────────────────────────────────────>│
  │                                         │
  │  4. Device downloads firmware           │
  │     (presigned URL, 1hr expiry)         │
  │                                         │
  │  5. Verify checksum                     │
  │                                         │
  │  6. Apply update and reboot             │
  │                                         │
  │  7. Report new version                  │
  │<────────────────────────────────────────│
  │                                         │
  │  8. Update device record                │

Firmware Storage

Firmware binaries are stored in S3-compatible object storage with organization-scoped paths:

# S3 key format
firmware/{organization_id}/{version}/{sha256_checksum}.bin

# Example
firmware/org_xyz789/1.3.0/a1b2c3d4e5f6...abc.bin

Upload Requirements

Binary firmware file (.bin format)
SHA256 checksum for integrity verification
Semantic version number
Release notes (optional)

Update Strategies

Single Device Update

Update a specific device to a target firmware version:

Checks current firmware version on device
Verifies device is online and reachable
Generates presigned download URL (1-hour expiry)
Queues update job via async worker

Bulk Fleet Update

Update multiple devices using deployment strategies:

Strategy	Description
All-at-Once	Push firmware to all target devices simultaneously
Rolling	Update devices in sequential batches
Canary	Update a small percentage first, then the rest

Update Status

Status	Description
`idle`	No update in progress
`updating`	Firmware download/install in progress
`completed`	Update applied successfully
`failed`	Update failed (device remains on previous version)

OTA Device Record

{
  "device_id": "dev_abc123",
  "current_version": "1.2.3",
  "target_version": "1.3.0",
  "ota_status": "updating",
  "progress": 65,
  "last_update_at": "2026-02-21T12:00:00Z"
}

Rollback

If an update fails or causes issues, EdgeFlow supports rolling back to the previous firmware version. The rollback process re-initiates an OTA update using the last known good firmware binary, which remains stored in S3.

Force Update

By default, OTA updates skip devices already running the target version. Use the force flag to override version checks and re-apply the firmware, useful for recovering from corrupted installations.

Security

SHA256 Checksums — Every firmware binary is verified before and after download
Presigned URLs — Download links expire after 1 hour
Organization Scoping — Firmware is isolated per organization in S3
TLS Transport — All downloads use HTTPS