watcher-ts/docs

Watcher Documentation

This document is specifically focused on standing up a minimal core version of the Laconic Stack without using Stack Orchestrator. If this is your first foray into the stack, start with Stack Orchestrator. To understand what is going on under the hood or to make contributions to this repo, this is a good place to start.

There are 3 main components to setting up an environment for running watchers:

• core services
• configure postgres
• edit config file

After which you should be able to navigate to the README.md of any watcher and run through its demo using yarn. The common yarn CLI commands for watchers are documented here.

Core services

The following core services should be setup and running on localhost:

• cerc-io/go-ethereum v1.10.26-statediff-4.2.2-alpha on port 8545

• cerc-io/ipld-eth-server v4.2.2-alpha with native GQL API enabled, on port 8082

• cerc-io/ipld-eth-db v4.2.2-alpha is the postgres schema required for ipld-eth-server

Setup Postgres

In this example, we use the erc20-watcher; for another watcher substitute with its name.

Create a postgres database for the watcher:

sudo su - postgres
createdb erc20-watcher

Create a postgres database for the job queue:

sudo su - postgres
createdb erc20-watcher-job-queue

Enable the pgcrypto extension on the job queue database.

postgres@tesla:~$ psql -U postgres -h localhost erc20-watcher-job-queue
Password for user postgres:
psql (12.7 (Ubuntu 12.7-1.pgdg18.04+1))
SSL connection (protocol: TLSv1.3, cipher: TLS_AES_256_GCM_SHA384, bits: 256, compression: off)
Type "help" for help.

erc20-watcher-job-queue=# CREATE EXTENSION pgcrypto;
CREATE EXTENSION
erc20-watcher-job-queue=# exit

Config File

In each watchers' directory is a config file: packages/<watcher>/environments/local.toml:

• Update the database connection settings.
• Update the upstream config and provide the ipld-eth-server GraphQL API endpoint.
• Select "active" vs. "lazy" watcher depending on its kind.

For example:

[server]
  kind = "active"

[database]
  type = "postgres"
  host = "localhost"
  port = 5432
  database = "erc20-watcher"
  username = "postgres"
  password = "postgres"

[jobQueue]
  dbConnectionString = "postgres://postgres:postgres@localhost/erc20-watcher-job-queue"

[upstream]
  [upstream.ethServer]
    gqlApiEndpoint = "http://127.0.0.1:8082/graphql"
    rpcProviderEndpoint = "http://127.0.0.1:8081"

Now that your environment is setup, you can test run any watcher!