Interchain query relayer implementation for Neutron.

More on relayer in neutron-docs

Running in development

Natively

• export environment you need (e.g. export $(grep -v '^#' .env.example | xargs) note: change rpc addresses to actual)
• make dev

For more configuration parameters see Environment section.

In Docker

1. Build docker image make build-docker
2. Run docker run --env-file .env.example -v $PWD/../neutron/data:/data -p 9999:9999 neutron-org/neutron-query-relayer
   • note: this command uses relative path to mount keys, run this from root path of neutron-query-relayer
   • note: with local chains use host.docker.internal in RELAYER_NEUTRON_CHAIN_RPC_ADDR and RELAYER_TARGET_CHAIN_RPC_ADDR instead of localhost/127.0.0.1
   • note: on Linux machines it is necessary to pass --add-host=host.docker.internal:host-gateway to Docker in order to make container able to access host network

Testing

Run unit tests

$ make test

Testing with 2 neutron-chains (easier for development) via cli

prerequisites

Clone the following repositories to the same folder where the neutron-query-relayer folder is located:

1. git clone git@github.com:neutron-org/neutron.git
2. git clone git@github.com:neutron-org/neutron-dev-contracts.git
3. git clone git@github.com:neutron-org/neutron-integration-tests.git for testing using docker

terminal 1

1. cd neutron
2. make build && make init && make start-rly

terminal 2

1. cd neutron-dev-contracts
2. run test_*.sh files from the root of the neutron-dev-contracts project (e.g. ./test_tx_query_result.sh).

terminal 3

1. cp .env.example.dev .env, edit .env if desired
2. export $(grep -v '^#' .env | xargs) && make dev

Testing via docker

1. cd neutron-integration-tests
2. read and run preparation steps described in the README.md file
3. run tests as described in the README.md file

In case of unexpected behaviour (e.g. tests failure) you can inspect neutron and relayer logs by doing the following:

Neutron:

1. docker ps
2. find the neutron container id
3. docker exec -it neutron_id bash
4. cd /opt/neutron/data
5. observe neutron logs in file test-1.log

Relayer:

1. docker ps
2. find the relayer container id
3. docker logs -f relayer_id

Configuration

Environment

Key	type	description	optional
RELAYER_NEUTRON_CHAIN_RPC_ADDR	string	rpc address of neutron chain	required
RELAYER_NEUTRON_CHAIN_REST_ADDR	string	rest address of neutron chain	required
RELAYER_NEUTRON_CHAIN_HOME_DIR	string	path to keys directory	required
RELAYER_NEUTRON_CHAIN_SIGN_KEY_NAME	string	key name	required
RELAYER_NEUTRON_CHAIN_TIMEOUT	time	timeout of neutron chain provider	optional
RELAYER_NEUTRON_CHAIN_GAS_PRICES	string	specifies how much the user is willing to pay per unit of gas, which can be one or multiple denominations of token	required
RELAYER_NEUTRON_CHAIN_GAS_LIMIT	string	the maximum price a relayer user is willing to pay for relayer's paid blockchain actions	required
RELAYER_NEUTRON_CHAIN_GAS_ADJUSTMENT	float	used to scale gas up in order to avoid underestimating. For example, users can specify their gas adjustment as 1.5 to use 1.5 times the estimated gas	required
RELAYER_NEUTRON_CHAIN_CONNECTION_ID	string	neutron chain connection ID	required
RELAYER_NEUTRON_CHAIN_DEBUG	bool	flag to run neutron chain provider in debug mode	optional
RELAYER_NEUTRON_CHAIN_KEYRING_BACKEND	string	see	required
RELAYER_NEUTRON_CHAIN_OUTPUT_FORMAT	json OR yaml	neutron chain provider output format	required
RELAYER_NEUTRON_CHAIN_SIGN_MODE_STR	string	see also consider use short variation, e.g. direct	optional
RELAYER_TARGET_CHAIN_RPC_ADDR	string	rpc address of target chain	required
RELAYER_TARGET_CHAIN_ACCOUNT_PREFIX	string	target chain account prefix	required
RELAYER_TARGET_CHAIN_VALIDATOR_ACCOUNT_PREFIX	string	target chain validator account prefix	required
RELAYER_TARGET_CHAIN_TIMEOUT	time	timeout of target chain provider	optional
RELAYER_TARGET_CHAIN_DEBUG	bool	flag to run target chain provider in debug mode	optional
RELAYER_TARGET_CHAIN_OUTPUT_FORMAT	json or yaml	target chain provider output format	optional
RELAYER_REGISTRY_ADDRESSES	string	a list of comma-separated smart-contract addresses for which the relayer processes interchain queries	required
RELAYER_ALLOW_TX_QUERIES	bool	if true relayer will process tx queries (if false, relayer will drop them)	required
RELAYER_ALLOW_KV_CALLBACKS	bool	if true, will pass proofs as sudo callbacks to contracts	required
RELAYER_MIN_KV_UPDATE_PERIOD	uint	minimal period of queries execution and submission (not less than n blocks)	optional
RELAYER_STORAGE_PATH	string	path to leveldb storage, will be created on given path if doesn't exists (required if RELAYER_ALLOW_TX_QUERIES is true)	optional
RELAYER_CHECK_SUBMITTED_TX_STATUS_DELAY	uint	delay in seconds to wait before transaction is checked for commit status	optional
RELAYER_QUERIES_TASK_QUEUE_CAPACITY	int	capacity of the channel that is used to send messages from subscriber to relayer (better set to a higher value to avoid problems with Tendermint websocket subscriptions).	optional
RELAYER_INITIAL_TX_SEARCH_OFFSET	uint	if set to non zero and no prior search height exists, it will initially set to (last_height - X). Set this if you have lots of old tx's on first start you don't need.	optional
RELAYER_LISTEN_ADDR	string	listener address for webserver json api you can query and prometheus metrics	optional

Logging

We are using a little modified zap.Logger, the modification can be seen at the neutron-logger repository. The default version of the logger used in the application is a little bit modified zap.NewProduction. The logger level can be set via the LOGGER_LEVEL env variable. If there is a need for a more significant customisation of the logger behaviour, see the neutron-logger repository readme.

Generate Openapi

The relayer uses a generated swagger client to retrieve queries information from Neutron. You can re-generate the Go client from ./internal/subscriber/querier/openapi.yml by running:

make generate-openapi

The swagger specs can be taken from the Neutron repo (you need to remove most of the generated specification).

Querying api server

You can query any running relayer as an api webserver.

Print available queries:

go run ./cmd/neutron_query_relayer query