API endpoint to set a channel fee

[rakanalh]

Abstract

Currently, Raiden implements ActionChannelSetFee which is currently used when the --flat-fee and --proportional-fee CLI flags are used to set the fee amounts for all channels.

raiden/raiden/raiden_service.py

Lines 976 to 1011 in 36b1fa0

	def _initialize_channel_fees(self) -> None:
	""" Initializes the fees of all open channels to the latest set values.
	This includes a recalculation of the dynamic rebalancing fees.
	"""
	chain_state = views.state_from_raiden(self)
	fee_config: MediationFeeConfig = self.config["mediation_fees"]
	token_addresses = views.get_token_identifiers(
	chain_state=chain_state, token_network_registry_address=self.default_registry.address
	)
	for token_address in token_addresses:
	channels = views.get_channelstate_open(
	chain_state=chain_state,
	token_network_registry_address=self.default_registry.address,
	token_address=token_address,
	)
	for channel in channels:
	# get the flat fee for this network if set, otherwise the default
	flat_fee = fee_config.get_flat_fee(channel.token_network_address)
	log.info(
	"Updating channel fees",
	channel=channel.canonical_identifier,
	flat_fee=flat_fee,
	proportional_fee=fee_config.proportional_fee,
	proportional_imbalance_fee=fee_config.proportional_imbalance_fee,
	)
	state_change = actionchannelupdatefee_from_channelstate(
	channel_state=channel,
	flat_fee=flat_fee,
	proportional_fee=fee_config.proportional_fee,
	proportional_imbalance_fee=fee_config.proportional_imbalance_fee,
	)
	self.handle_and_track_state_changes([state_change])

raiden/raiden/blockchain/decode.py

Lines 328 to 344 in 36b1fa0

	def actionchannelupdatefee_from_channelstate(
	channel_state: NettingChannelState,
	flat_fee: FeeAmount,
	proportional_fee: ProportionalFeeAmount,
	proportional_imbalance_fee: ProportionalFeeAmount,
	) -> ActionChannelUpdateFee:
	imbalance_penalty = calculate_imbalance_fees(
	channel_capacity=get_capacity(channel_state),
	proportional_imbalance_fee=proportional_imbalance_fee,
	)
	return ActionChannelUpdateFee(
	canonical_identifier=channel_state.canonical_identifier,
	fee_schedule=FeeScheduleState(
	flat=flat_fee, proportional=proportional_fee, imbalance_penalty=imbalance_penalty
	),
	)

There should be a way for the user to be able to set fee parameters for each channel individually and through the WebUI.

Specification

• Implement an API endpoint which allows for setting the fee parameters similar to the code above.
• Write new tests cover this new endpoint.
• Create an issue in the WebUI repo to integrate this endpoint.