NervesHub device config

nerves_hub.ex

# Error

# 401 Unauthorized when connecting to NervesHub
{:error, {:upgrade_failure, %{
  reason: %Mint.WebSocket.UpgradeFailureError{status_code: 401, ...},
  status_code: 401
}}}

# Configuration Files

# config/nerves_hub.exs:
# Using SharedSecret authentication
config :nerves_hub_link,
  host: System.get_env("NERVESHUB_HOST", "devices.nervescloud.com"),
  connect: true,
  remote_iex: true,
  shared_secret: [
    product_key: System.get_env("NERVESHUB_PRODUCT_KEY"),
    product_secret: System.get_env("NERVESHUB_PRODUCT_SECRET")
  ],
  configurator: NervesHubLink.Configurator.SharedSecret,
  socket: [
    json_library: Jason,
    heartbeat_interval: 45_000
  ],
  client: ScoutHub.NervesHubClient

# config/runtime.exs:
# Sets device identifier at runtime
config :nerves_hub_link,
  device_identifier: Nerves.Runtime.serial_number()

"""
Environment Variables (from .env.nerveshub):
- NERVESHUB_PRODUCT_KEY
- NERVESHUB_PRODUCT_SECRET
- Host: defaults to devices.nervescloud.com
"""