Depeg-ui

This repository contains the source code for web application to the Etherisc depeg-contracts.

When starting the application, the webapplication is exposed on port 3000 (or the port specified in the environment variable PORT) and path /. Additionally to the frontend, the application also exposes an API on path /api.

API services

The nextjs backend these services:

Bundles

• GET /api/bundles/update - retrieves all bundles and stores them in redis store
• GET /api/bundles/clear - purge all bundles from redis store
• GET /api/bundles/all - retrieves all bundles from redis store
• GET /api/bundles/active - retrieves all active bundles (which can be used to issue policies) from redis store

Prices

• GET /api/prices/fetch - retrieves all prices from the blockchain (up to the latest price already stored) and stores them in redis store
• GET /api/prices/clear - purge all prices from redis store
• GET /api/prices/all - retrieves all prices from redis store. Parameters
  • after - only return prices after this timestamp
  • count - only return this number of prices
  • page - only return prices for this page (page size is count)
• GET /api/prices/latest - retrieves the latest price from redis store

Dependencies

Redis

The application uses redis to store information. The redis modules search and JSON need to enabled. The application expects a environment variables called REDIS_URL to be set. The application will use the url'redis://redis:6379' if no connection is specified in the REDIS_URL.

The docker image redis/redis-stack can be used to run a redis instance with the required modules enabled.

Deployed contracts

The application expects that the depeg-contracts are deployed to the blockchain. Use the two environment variables NEXT_PUBLIC_DEPEG_CONTRACT_ADDRESS and NEXT_PUBLIC_STAKING_CONTRACT_ADDRESS to specify the addresses of the depeg product and staking contracts. The expected version of the contracts can be found in the package.json file (look for the package @etherisc/depeg-contracts).

IP Access limit

To limit access to the API to a list of IP addresses, the application expects a environment variable called API_IP_ALLOWED to be set. The variable should contain a comma separated list of IP addresses. If the variable is not set, no IP access limit is applied.

Run in development mode

The repository includes a vscode devcontainer that installs all the necessary dependencies to run the application.

Create a .env.local file in the root directory of the project. Have a look a the .env.example_local file for the required environment variables of a setup running again a local ganache chain. The minimum required variables are described below Then run the application in dev mode with npm run dev.

Configuration

General config

# Blockchain connection configuration
NEXT_PUBLIC_CHAIN_ID=80001
NEXT_PUBLIC_CHAIN_NAME=Polygon Mumbai
NEXT_PUBLIC_CHAIN_RPC_URL=https://polygon-testnet-rpc.allthatnode.com:8545
NEXT_PUBLIC_CHAIN_TOKEN_NAME=TEST-MATIC
NEXT_PUBLIC_CHAIN_TOKEN_SYMBOL=MATIC
NEXT_PUBLIC_CHAIN_TOKEN_DECIMALS=18
NEXT_PUBLIC_CHAIN_TOKEN_BLOCKEXPLORER_URL=https://mumbai.polygonscan.com/
NEXT_PUBLIC_CHAIN_TOKEN_FAUCET_URL=https://faucet.polygon.technology/

# private chain rpc url for backend
#BACKEND_CHAIN_RPC_URL=https://polygon-testnet-rpc.allthatnode.com:8545

# Depeg configuration
NEXT_PUBLIC_DEPEG_CONTRACT_ADDRESS=0x5930513a430E4D0171870aAe73c1e70edcc1917d
NEXT_PUBLIC_STAKING_CONTRACT_ADDRESS=0xe360b8B3abd807e7b02eCaCd8DfA083cFF0f4941
NEXT_PUBLIC_DEPEG_USD1=USDC
NEXT_PUBLIC_DEPEG_USD1_DECIMALS=6
NEXT_PUBLIC_DEPEG_USD2=USDT
NEXT_PUBLIC_DEPEG_USD2_DECIMALS=6
NEXT_PUBLIC_DEPECT_TOKEN_DISPLAY_PRECISION=2
NEXT_PUBLIC_DEPEG_LIFETIME_DAYS_MINIMUM=14
NEXT_PUBLIC_DEPEG_LIFETIME_DAYS_MAXIMUM=180
NEXT_PUBLIC_DEPEG_PROTECTED_AMOUNT_MINIMUM=1000
NEXT_PUBLIC_DEPEG_PROTECTED_AMOUNT_MAXIMUM=50000
NEXT_PUBLIC_DEPEG_COVERAGE_DURATION_DAYS_MINIMUM=7
NEXT_PUBLIC_DEPEG_COVERAGE_DURATION_DAYS_MAXIMUM=180
NEXT_PUBLIC_DEPEG_STAKED_AMOUNT_MINIMUM=25000
NEXT_PUBLIC_DEPEG_STAKED_AMOUNT_MAXIMUM=100000
NEXT_PUBLIC_DEPEG_ANNUAL_PCT_RETURN=5
NEXT_PUBLIC_DEPEG_ANNUAL_PCT_RETURN_MAXIMUM=10

Override Riskpool capacity limit

Check the riskpool capacity limit and show a warning if the limit is reached (works only if the configured limit is smaller than then limit defined in the smart contract).

• NEXT_PUBLIC_RISKPOOL_CAPACITY_LIMIT=250000 - configure the riskpool capacity limit to USD2 250000

Feature flags

Gasless transactions

Enable gasless transactions for the application

• NEXT_PUBLIC_FEATURE_GASLESS=true - enable gasless transactions
• Make sure the depeg-backend-processor service is running and connected to the same redis and product. The backend processor is responsible for sending the signed transactions to the blockchain.

Price

Show a page that displays the latest price of the protected coin and (if enabled) the price history of the protected coin.

• NEXT_PUBLIC_FEATURE_PRICE=true - show latest price of the protected coin
• NEXT_PUBLIC_FEATURE_PRICE_HISTORY=true - show price history of the protected coin
• NEXT_PUBLIC_FEATURE_PRICE_HISTORY_FAKE_DATA=true - enable loading of fake data for price history (for testing)

Backend bundle cache

The backend caches the current bundles from the blockchain in a local redis store. This information will be updated when a new bundle is created or a policy has been issued.

The detect outside changes (e.g. when a change to a bundle has been made from the blockchain explorer or a brownie shell) the backend api /api/bundles/update should be called on a regular basis (e.g. via a cron job that runs every 10 minutes) to ensure those updates are reflected in the redis store and the ui.

Backend price cache

The backend caches the prices from the blockchain in a local redis store.

The detect changes the backend api /api/prices/fetch should be called on a regular basis (e.g. via a cron job that runs every minute) to ensure availability of the latest prices in the ui.

Faucet

NEXT_PUBLIC_SHOW_FAUCET=true
NEXT_FAUCET_MNEMONIC=candy maple cake sugar pudding cream honey rich smooth crumble sweet treat
NEXT_PUBLIC_FAUCET_SYMBOL=USDT
NEXT_PUBLIC_FAUCET_COIN_ADDRESS=0x000Ea55EcF8E37477c2216B4416AB43147F32509
NEXT_FAUCET_SEND_ETHERS=true
NEXT_FAUCET_SEND_TESTCOIN=true

Fake depeg event on test systems

To initiate a fake depeg event these steps are required

1. Set environment variables
   • NEXT_PUBLIC_FEATURE_FAKE_DEPEG_ENABLED=true
   • NEXT_FAKE_DEPEG_PRODUCT_OWNER_MNEMONIC=...
   • NEXT_FAKE_DEPEG_PRODUCT_OWNER_HD_WALLET_INDEX=x - (optional) if the product owner is derived from a hd wallet
2. Use a PriceDataProvider that is fed through the depeg-monitor with fake prices
3. Trigger a depeg event by calling an HTTP PUT to /v1/feeder/set_state/triggered on the depeg monitor
4. Wait a bit for the price feed to go into triggered state (how long to wait depends in the price feed config)
5. Trigger a depeg event by calling an HTTP PUT to /v1/feeder/set_state/depegged on the depeg monitor
6. Wait a bit for the price feed to go into depegged state (how long to wait depends on price feed config)
7. Confirm depeg by calling the api /api/fake-depeg/confirm which will store the latest blocknumber as the time of depeg (technically not correct, but good enough for testing)
8. Execute some claims through the UI
9. Call the api /api/fake-depeg/process to process these claims and issue immediate payout
10. If you want to reset the system to be able to issue new policies, call an HTTP PUT to /v1/product/reactivate and /v1/feeder/set_state/stable on the monitor to reset the price feed.
11. Finally reset fake data in the api by calling /api/fake-depeg/reset

Run docker image locally with mumbai instance configuration

docker build -t depeg-ui --build-arg INSTANCE=mumbai .
docker run --rm -p 3002:3000 -e HOSTNAME=0.0.0.0 depeg-ui

open browser at http://localhost:3002

Deployment

Docker

The application can be run in a docker container. The docker image can be build via the provided Dockerfile. We do not currently provide a prebuilt docker image as the image includes static instance information that needs to be configured at build time.

The build process requires the following arguments:

• INSTANCE - the name of the instance to build the image for. The instance name is used to load the correct configuration from the .env.INSTANCE file in the root diretory of the project (see .env.mumbai as an example).

Dokku Deployment

We use dokku for deployment.

With the current setup (dokku repo is added as remote repo called dokku to the local git), deployment is triggered by running the following command in the root directory of the project:

npm version <major|minor|patch> 
git push && git push --tags
git push <dokku-remote-repo> <branch-to-deploy>:main

Initial instance setup

Replace application name (goerli-setup) with whatever fits your need. DNS is expected to be prepared in advance.

# create dokku application 
dokku apps:create goerli-depeg

# add new domain and remove default domain
dokku domains:add goerli-depeg depeg.goerli.etherisc.com
dokku domains:remove goerli-depeg goerli-depeg.depeg-test.etherisc.com

# configure dokku docker build to load correct instance environment during build
dokku docker-options:add goerli-depeg build --build-arg INSTANCE=goerli

# set correct proxy ports for http and https
dokku proxy:ports-add goerli-depeg https:443:3000
dokku proxy:ports-add goerli-depeg http:80:3000
dokku proxy:ports-remove goerli-depeg http:80:5000

# create redis service
dokku redis:create depeg-test-goerli-redis -i redis/redis-stack-server -I 7.2.0-v0

# now you need to manually enable redissearch and redisjson modules in the redis config (replace 'depeg-mumbai-redis' below with correct service name)
vi /var/lib/dokku/services/redis/depeg-mumbai-redis/config/redis.conf
# scroll down to the section 'MODULES' and paste the following two lines (remove the # in front of the lines)
# loadmodule /opt/redis-stack/lib/redisearch.so
# loadmodule /opt/redis-stack/lib/rejson.so

# restart redis service
dokku redis:restart depeg-mumbai-redis
# link the redis service to the app
dokku redis:link depeg-test-goerli-redis goerli-depeg

# now push deployment via git 
# 1. add new git remote 'git remote add dokku-goerli dokku@<host>:goerli-depeg'
# 2. 'git push dokku-goerli develop:main'

# enable let's encrypt for https certificates
dokku letsencrypt:enable goerli-depeg

# configure backend chain rpc url
dokku config:set goerli-depeg BACKEND_CHAIN_RPC_URL=<chain rpc url>
dokku config:set goerli-depeg HOSTNAME=0.0.0.0

# initial update of the bundle cache (probably empty)
curl https://<application-url>/api/bundles/update
# initial fetch of the price data (must be done twice the first time - if index is not initialized yet)
curl https://<application-url>/api/prices/fetch

# app should be ready now - open in browser

# do not forget to configure a cronjob to regularly update the bundles. e.g.
# '*/5 * * * * curl https://depeg.goerli.etherisc.com/api/bundles/update'
# '* * * * * curl https://depeg.goerli.etherisc.com/api/prices/fetch'

Dokku redis debug connection

Example using service depeg-mumbai-redis:

1. Expose redis port on dokku dokku redis:expose depeg-mumbai-redis
2. Find the exposed port in the output above or via dokku redis:info depeg-mumbai-redis
3. Open ssh tunnel with dokku redis port forward ssh -L 6479:localhost:15956 user@host
4. Now connect with redis client of choice (e.g. RedisInsight) using localhost:6479 as host and the password mentioned in redis info
5. When finished, close the ssh tunnel by logging out of the ssh shell and unexpose the redis port dokku redis:unexpose depeg-mumbai-redis

Dokku documentaton links:

• https://dokku.com/docs/deployment/application-deployment/
• https://dokku.com/docs/advanced-usage/docker-options/
• https://dokku.com/docs/configuration/domains/
• https://github.com/dokku/dokku-redis
• https://hub.docker.com/r/redis/redis-stack