chore: add readme for indexer (#12)

* chore: add readme for indexer

README.md

@@ -1 +1,91 @@
-# babylon-staking-indexer
+# Babylon BTC Staking Indexer
+
+## Overview
+
+The **Babylon BTC Staking Indexer** is a core component of the 
+Babylon blockchain’s staking architecture, responsible for syncing delegation 
+and finality provider events from both the **Babylon blockchain (BBN)** and 
+**Bitcoin (BTC)**. It processes, stores, and transforms on-chain events into 
+API-friendly data structures, enabling the Babylon Staking API to efficiently 
+serve staking-related data to the frontend.
+
+### Key Responsibilities
+
+- **Delegation Sync**: Syncs delegation and Babylon&BTC-related events, storing them in 
+MongoDB for easy retrieval.
+- **Finality Provider Sync**: Tracks and updates the state of finality providers
+ (FPs), including status changes, creation, and edits.
+- **Global Parameters Sync**: Syncs global parameters necessary for the staking 
+mechanism.
+- **Event Replay(pending)**: Allows manual operations like event replays, triggered by 
+the Admin Portal or CLI, to recover or adjust state after chain forks or re-orgs.
+
+## Architecture
+
+The Babylon Indexer interacts with the following components:
+
+- **BBN (Babylon Blockchain)**: Receives delegation and finality provider events
+ via Cosmos CometBFT `/block_results` (over gRPC for better performance), as well
+ as websocket subscription on events.
+- **BTC (Bitcoin)**: Syncs withdrawal transactions and other BTC-related events.
+- **MongoDB**: Serves as the storage layer where delegation, global parameters 
+and finality provider data is stored.
+- **API Event Queue**: The indexer pushes API-related events into a queue 
+(RabbitMQ), consumed by the Babylon API for frontend-facing operations.
+- **Admin Portal/CLI**: Provides interfaces for triggering event replays and 
+other manual interactions with the indexer.
+- **Data Transformation Service (Optional)**: Transforms delegation data from 
+the indexer into other formats to backfill or migrate data for API as needed.
+
+![Architecture Diagram](./doc/diagram.jpg)
+
+## Synchronization Process
+
+The workflow involves:
+
+1. **Bootstrap Process**: The indexer starts by syncing all events from the 
+last processed Babylon block height to the latest height. 
+This is a continuous process until it catches up with the most recent block.
+2. **Real-time Sync**: After catching up, the indexer subscribes to 
+real-time WebSocket events for ongoing synchronization.
+3. **Raw Data Synchronization**: The indexer primarily handles the 
+synchronization of:
+   - **Delegation**: Storing and tracking delegation data.
+   - **Finality Provider**: Monitoring state changes and updates for 
+   finality providers.
+   - **Global Parameters**: Syncing parameters relevant to staking, unbonding, 
+   and slashing.
+
+4. **RabbitMQ Messaging**: When a state change occurs in any delegation, 
+the indexer emits a message into RabbitMQ. This allows the Babylon API to 
+perform metadata and statistical calculations, such as total value locked (TVL) 
+computations.
+5. **Bitcoin Node Sync**: The indexer also syncs with the Bitcoin node to 
+check if delegations are in a withdrawn state, ensuring accurate tracking of 
+withdrawal transactions.
+
+## Installation & Setup
+
+### Requirements
+
+- **Go**: Version `1.23.2` or higher is required.
+- **MongoDB**: A MongoDB instance with replica sets enabled is required
+
+1. Clone the repository
+
+```bash
+git clone git@github.com:babylonlabs-io/babylon-staking-indexer.git
+cd babylon-staking-indexer
+```
+
+2. Install dependencies
+
+```bash
+go mod tidy
+```
+
+3. Run the service
+
+```bash
+make run-local
+```

bin/local-startup.sh

@@ -1,13 +1,13 @@
 #!/bin/bash
 
 # Check if the MongoDB container is already running
-MONGO_CONTAINER_NAME="mongodb"
+MONGO_CONTAINER_NAME="indexer-mongodb"
 if [ $(docker ps -q -f name=^/${MONGO_CONTAINER_NAME}$) ]; then
-    echo "MongoDB container already running. Skipping MongoDB startup."
+    echo "Indexer mongoDB container already running. Skipping MongoDB startup."
 else
-    echo "Starting MongoDB"
-    # Start MongoDB
-    docker compose up -d mongodb
+    echo "Starting indexer mongoDB"
+    # Start indexer mongoDB
+    docker compose up -d indexer-mongodb
 fi
 
 # Check if the RabbitMQ container is already running

config/config-docker.yml

@@ -4,7 +4,7 @@ poller:
 db:
   username: root
   password: example
-  address: "mongodb://localhost:27017"
+  address: "mongodb://indexer-mongodb:27017/?directConnection=true"
   db-name: babylon-staking-indexer
 btc:
   endpoint: localhost:18332

docker-compose.yml

@@ -12,8 +12,8 @@ services:
       - ./config/config-docker.yml:/home/babylon-staking-indexer/config.yml:Z
   mongodb:
     image: mongo:latest
-    container_name: mongodb
-    hostname: mongodb
+    container_name: indexer-mongodb
+    hostname: indexer-mongodb
     ports:
       - "27017:27017"
     environment: