add indexer docs

src/SUMMARY.md

@@ -46,6 +46,7 @@
   - [Full Node Setup](./infrastructure-full-node-setup.md)
   - [Collator Setup](./infrastructure-collator-setup.md)
   - [Public Rpc Setup](./infrastructure-rpc-setup.md) 
+  - [Indexer](./infrastructure-indexer.md)
 - [Support Us](./support-us.md)
   - [Donate](./support-us-donate.md)
   - [Nominate](./support-us-nominate.md)

src/infrastructure-indexer.md

@@ -0,0 +1,91 @@
+# Indexer
+
+If you run your own node, you may want to run your own indexer for better privacy and autonomy.
+
+## LiteScan
+
+Encointer uses a very simple low-level indexer called [LiteScan](https://github.com/pifragile/litescan) and extends it with its own types.
+
+### Setup 
+
+We assume you're running your node on the same ubuntu 22.04 machine. We want to run the indexer as a service, feeding into a mongodb database.
+
+```bash
+sudo apt install -y mongodb-org curl
+```
+To run a node program as a service, install [PM2](https://pm2.io/docs/runtime/guide/installation/)
+```bash
+sudo npm install pm2 -g
+```
+
+Install nvm and node >=20
+```bash
+curl -o- https://raw.githubusercontent.com/nvm-sh/nvm/v0.40.1/install.sh | bash
+nvm install 20
+```
+
+
+```bash
+git clone https://github.com/brenzi/litescan.git
+cd litescan
+git checkout encointer
+npm install
+```
+
+### MongoDB
+
+We encourage you to pick strong passwords in the following steps. We will create the `admin` user and `litescan`with r/w permission as well as `encointer`with read permission for queries 
+
+```bash
+sudo service mongod start
+mongosh
+use admin
+db.createUser( { user: "admin", pwd: "*****", roles: [ { role: "userAdminAnyDatabase", db: "admin" } ] } )
+use encointer-kusama
+db.createUser({user: "litescan", pwd: "******", roles: [{ role: "readWrite", db: "encointer-kusama" }]})
+db.createUser({user: "encointer", pwd: "*******", roles: [{ role: "read", db: "encointer-kusama" }]})
+```
+
+### Test Indexer
+
+Now we need to configure the indexer. Create a `.env` file in the repo root. Make sure to adjust according to your setup.
+
+```bash 
+DB_URL=mongodb://litescan:*******@localhost:27017/?authSource=encointer-kusama
+NUM_CONCURRENT_JOBS=1000
+START_BLOCK=508439
+DB_NAME=encointer-kusama
+RPC_NODE=ws://127.0.0.1:9944
+```
+
+Now you can run the indexer
+
+```bash
+node index.js
+```
+
+you should see block sync happening
+
+### Run as Service
+
+To make sure the indexer is always up, we run it as a service. 
+
+```bash
+pm2 start index.js --name encointer-indexer
+pm2 save
+pm2 startup
+```
+And execute the suggested command to make the service start on boot.
+
+
+## Querying
+
+You can now run any [MongoDB Query](https://www.mongodb.com/docs/manual/tutorial/query-documents/) against the database. 
+
+We recommend [mongodb compass](https://www.mongodb.com/products/tools/compass) to browse the database
+
+As a simple cli example, let's query the highest indexed block:
+
+```bash
+mongosh --username encointer --eval "db.blocks.find().sort({height: -1}).limit(1)" encointer-kusama
+```