price-oracle

Aggregates and caches price data feeds from external data providers.

Usage

Configuration

Description of the emeris-price-oracle.toml setting file.

Key Feature Settings

• interval: The delay time of the function for an external price provider api request.
• whitelistfiats : List of fiats you want to request (default currency is USD)
• coinmarketcapapikey : This is the api-key of the provider.
• fixerapikey : This is the api-key of the provider.
• Provider : The endpoint address of the price provider.

For Binance, apikey does not exist.

example(Local exec)

#kubectl port-forward service/cockroachdb-public 26257
DatabaseConnectionURL = "postgres://[email protected]:26257?sslmode=disable"
ListenAddr = "127.0.0.1:9898"
Debug = true
LogPath = "/home/ubuntu/log"
interval = "10s"
whitelistfiats = ["EUR","KRW","CHF"]
#Not currently used, but may be used in the future
coinmarketcapapikey =""
fixerapikey = ""

Local exec DB

database/schema Set the cockroach DB to the local cluster, connect to the local DB, and run schema as it is.

*The cns version brunch does not require a separate run.

Build

# build
go build

# executable
./navigator-price-oracle

Use

Given an exchange API, the price oracle will periodically check with it prices of the tokens we're interested in monitoring, and cache the result until the next period:

1. At startup, oracle will grab data from the API and expose it on GET /prices
2. Once every 10 seconds, new data will be downloaded and cached
3. Once every 5minutes, 1 hour and 24 hour historical data will be collected from the Coin-gecko
4. Historical data will be exposed via GET /chart:id, this api takes one parameter named days and one optional parameter named vs_currency (default usd).

Oracle must return prices of all the tokens that it is configured to fetch.

An API to provide tokens configuration must be provided on POST /tokens:

{
	"tokens": [
		"ATOMUSDT",
		"KAVAUSDT"
	]
}

The same must be done for FIAT currencies on POST /fiats:

{
	"fiats": [
		"USDEUR",
		"USDKRW"
	]
}

Possible Problems

If you have multiple copy of in-memory cockroach db, it can happen that when you run

testserver.NewTestServer() it can stuck at waiting for download of SOME TMP DIR

Solution: if this happens manually delete ALL instances of test server from your machine.

Known issue

When try to download some private module from emerishq you can get: fatal: could not read Username for 'https://github.com': terminal prompts disabled

Solution: Set the goprivate env variable.

go env -w GOPRIVATE="github.com/emerishq/{module}"

Dependencies & Licenses

The list of non-{Cosmos, AiB, Tendermint} dependencies and their licenses are:

Module	License
alicebob/miniredis	MIT
gin-contrib/zap	MIT
gin-gonic/gin	MIT
go-playground/validator	MIT
go-playground/validator	MIT
go.uber.org/zap	MIT
jackc/pgx	MIT
jmoiron/sqlx	MIT
lib/pq	Open use
sigs.k8s.io/controller-runtime	MIT
sony/sonyflake	MIT
superoo7/go-gecko	MIT