Building & Deploying Subgraph (local node)

This tutorial will demonstrate how to build a subgraph and deploy it locally

Install the graph-cli

https://github.com/graphprotocol/graph-cli#installation

Build your own graph-indexer local node

Copy paste the below docker-compose file and replace services.graph-node.environment.ethereum accordingly to the network: mainnet s0 : mainnet:archive,traces:https://a.api.s0.t.hmny.io mainnet s1 : mainnet:archive,traces:https://a.api.s1.t.hmny.io

mainnet s0

version: "3"
services:
  graph-node:
    container_name: hmy_indexer
    image: graphprotocol/graph-node:latest
    ports:
      - "8000:8000"
      - "8001:8001"
      - "8020:8020"
      - "8030:8030"
      - "8040:8040"
    depends_on:
      - ipfs
      - postgres
    environment:
      postgres_host: postgres
      postgres_user: graph-node
      postgres_pass: let-me-in
      postgres_db: graph-node
      ipfs: "ipfs:5001"
      GRAPH_ETH_CALL_BY_NUMBER: 1
      GRAPH_ALLOW_NON_DETERMINISTIC_IPFS: 1
      ethereum: "mainnet:archive,traces:https://a.api.s0.t.hmny.io"
      RUST_LOG: info
  ipfs:
    container_name: ipfs
    image: ipfs/go-ipfs:v0.4.23
    ports:
      - "5001:5001"
    volumes:
      - ./data/ipfs:/data/ipfs
  postgres:
    image: postgres
    ports:
      - "5432:5432"
    command: ["postgres", "-cshared_preload_libraries=pg_stat_statements"]
    environment:
      POSTGRES_USER: graph-node
      POSTGRES_PASSWORD: let-me-in
      POSTGRES_DB: graph-node
    volumes:
      - ./data/postgres:/var/lib/postgresql/data

mainnet s1

and run your indexer node

docker-compose up -d
Creating network "thegraph_default" with the default driver
Creating ipfs ...
Creating postgres ...
Creating postgres done
Creating ipfs ... done
Creating indexer ... 
Creating indexer ... done

docker logs hmy_indexer -f should show the indexer synching with the harmony chain

docker logs hmy_indexer -f
Jul 29 05:33:22.849 INFO Graph Node version: 0.23.1 (2021-06-23)
Jul 29 05:33:22.861 INFO Generating configuration from command line arguments
Jul 29 05:33:22.909 INFO Starting up
Jul 29 05:33:22.911 INFO Trying IPFS node at: http://ipfs:5001/
Jul 29 05:33:22.928 INFO Creating transport, capabilities: archive, traces, url: https://api.s0.pops.one, provider: mainnet-rpc-0
Jul 29 05:33:22.948 INFO Successfully connected to IPFS node at: http://ipfs:5001/
Jul 29 05:33:23.680 INFO Connecting to Postgres, weight: 1, conn_pool_size: 10, url: postgresql://graph-node:HIDDEN_PASSWORD@postgres:5432/graph-node, pool: main, shard: primary
Jul 29 05:33:23.716 INFO Pool successfully connected to Postgres, pool: main, shard: primary, component: Store
Jul 29 05:33:23.721 INFO Setting up fdw, pool: main, shard: primary, component: ConnectionPool
Jul 29 05:33:23.728 INFO Running migrations, pool: main, shard: primary, component: ConnectionPool
Jul 29 05:33:24.748 INFO Migrations finished, pool: main, shard: primary, component: ConnectionPool
Jul 29 05:33:24.748 INFO Mapping primary, pool: main, shard: primary, component: ConnectionPool
Jul 29 05:33:24.767 INFO Connecting to Ethereum to get network identifier, capabilities: archive, traces, provider: mainnet-rpc-0
Jul 29 05:33:25.030 INFO Connected to Ethereum, capabilities: archive, traces, network_version: 0x6357d2e0, provider: mainnet-rpc-0
Jul 29 05:33:25.117 INFO Creating LoadManager in disabled mode, component: LoadManager
Jul 29 05:33:25.119 INFO Starting block ingestors
Jul 29 05:33:25.119 INFO Starting block ingestor for network, network_name: mainnet
Jul 29 05:33:25.120 INFO Starting job runner with 1 jobs, component: JobRunner
Jul 29 05:33:25.126 INFO Starting JSON-RPC admin server at: http://localhost:8020, component: JsonRpcServer
Jul 29 05:33:25.130 INFO Starting GraphQL HTTP server at: http://localhost:8000, component: GraphQLServer
Jul 29 05:33:25.130 INFO Starting index node server at: http://localhost:8030, component: IndexNodeServer
Jul 29 05:33:25.130 INFO Started all subgraphs, component: SubgraphRegistrar
Jul 29 05:33:25.130 INFO Starting metrics server at: http://localhost:8040, component: MetricsServer
Jul 29 05:33:25.131 INFO Starting GraphQL WebSocket server at: ws://localhost:8001, component: SubscriptionServer
Jul 29 05:33:25.258 INFO Downloading latest blocks from Ethereum. This may take a few minutes..., provider: mainnet-rpc-0, component: BlockIngestor
Jul 29 05:33:33.600 INFO Syncing 4 blocks from Ethereum., code: BlockIngestionStatus, blocks_needed: 4, blocks_behind: 4, latest_block_head: 12886125, current_block_head: 12886121, provider: mainnet-rpc-0, component: BlockIngestor
Jul 29 05:33:35.252 INFO Syncing 1 blocks from Ethereum., code: BlockIngestionStatus, blocks_needed: 1, blocks_behind: 1, latest_block_head: 12886126, current_block_head: 12886125, provider: mainnet-rpc-0, component: BlockIngestor

A few component are installed

Management: https://localhost:8020/ where subgraph are being created/deployed/deleted

Metrics / playground: https://localhost:8030/

Visit your playground using the URL http://127.0.0.1:8030/graphql/playground and start playing around with graphQL API.

An example of query you can use to show subgraph currently being indexed would be :

query {
  indexingStatuses {
    subgraph
    entityCount
    fatalError {
      handler
    }
    nonFatalErrors {
      handler
    }
    chains {
      network
      latestBlock {
        number
      }
      chainHeadBlock {
        number
      }
      lastHealthyBlock {
        number
      }
    }
  }
}

Right now of course, the result is empty

{
  "data": {
    "indexingStatuses": []
  }
}

Our first subgraph

lets use blocklytics/ethereum-blocks subgraph as example

git clone https://github.com/blocklytics/ethereum-blocks
cd ethereum-blocks

Edit package.json file and add these lines

"create-harmony": "graph create --node http://localhost:8020 harmony/blocks",
"deploy-harmony": "graph deploy --node http://localhost:8020 --ipfs http://localhost:5001 harmony/blocks",

It is highly recommended to minimize the number of blocks to be indexed to avoid putting load on the RPCs and to speed up the usage of your subgraph/application

Update the manifest

Update the manifest subgraph.yaml file datasources[0]['network'] from rinkeby to mainnet or testnet accordingly to how you edited the network in your docker-compose.yaml if there is no need to index the entire blockchain, you can add an attribute startBlock to speed up the sync : datasources[0]['source']['startBlock']

Also, update the subgraph.yaml apiVersion: 0.0.5

It is highly recommended to minimize the number of blocks to be indexed to avoid putting load on the RPCs and to speed up the usage of your subgraph/application

Create and deploy the subgraph

yarn codegen
yarn build
yarn create-harmony 
yarn deploy-harmony

Sync begins and you are good to query your subgraph http://localhost:8000/subgraphs/name/harmony/blocks/graphql

Note that the above example query should now show your something similar to the below

{
  "data": {
    "indexingStatuses": [
      {
        "chains": [
          {
            "chainHeadBlock": {
              "number": "12887470"
            },
            "lastHealthyBlock": null,
            "latestBlock": {
              "number": "10701810"
            },
            "network": "testnet"
          }
        ],
        "entityCount": "1812",
        "fatalError": null,
        "nonFatalErrors": [],
        "subgraph": "QmVDqqTJZM3ZHizSubG2H5b1vQ1Jp7iMD6Sc94A9zyRnAK"
      }
    ]
  }
}

data['indexingStatuses'][0]['chains'][0]['latestBlock']['number'] will indicate the last block synched

check your indexer log if the sync is stuck docker logs indexer -f --since 1m

How to write subgraphs

Official Graph's doc

https://thegraph.com/docs/developer/create-subgraph-hosted

Community article

https://medium.com/protofire-blog/subgraph-development-part-1-understanding-and-aggregating-data-ef0c9a61063d

https://medium.com/protofire-blog/subgraph-development-part-2-handling-arrays-and-identifying-entities-30d63d4b1dc6

Getting help

the Graph’s Discord server https://discord.gg/vtvv7FP