watcher-ts/packages/graph-test-watcher/demo.md
nikugogoi c299737aab
Add demo for graph-test-watcher (#267)
* Add demo for graph-test-watcher

* Remove stack-orchestrator from demos
2022-11-28 16:35:19 +05:30

4.6 KiB

Demo

  • The following core services need to be running for the demo:

  • Create a postgres12 database for the watcher:

    sudo su - postgres
    
    # If database already exists
    # dropdb graph-test-watcher
    
    createdb graph-test-watcher
    
  • Create database for the job queue and enable the pgcrypto extension on them (https://github.com/timgit/pg-boss/blob/master/docs/usage.md#intro):

    # If database already exists
    # dropdb graph-test-watcher-job-queue
    
    createdb graph-test-watcher-job-queue
    
    postgres@tesla:~$ psql -U postgres -h localhost graph-test-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.
    
    graph-test-watcher-job-queue=# CREATE EXTENSION pgcrypto;
    CREATE EXTENSION
    graph-test-watcher-job-queue=# exit
    
  • In the config file update the database connection settings.

  • In watcher-ts repo, follow the instructions in Setup for installing and building packages.

    # After setup
    yarn && yarn build
    
  • In packages/graph-node, deploy an Example contract:

    yarn example:deploy
    
  • Set the returned address to the variable $EXAMPLE_ADDRESS:

    EXAMPLE_ADDRESS=<EXAMPLE_ADDRESS>
    
  • In packages/graph-node/test/subgraph/example1/subgraph.yaml:

    • Set the source address for Example1 datasource to the EXAMPLE_ADDRESS.
    • Set the startBlock less than or equal to the latest mined block.
  • Build the example subgraph:

    yarn build:example
    
  • Run the job-runner:

    yarn job-runner
    
  • Run the watcher:

    yarn server
    
  • The output from the block handler in the mapping code should be visible in the job-runner for each block.

  • Run the following GQL subscription at the graphql endpoint http://127.0.0.1:3008/graphql

    subscription {
      onEvent {
        event {
          __typename
          ... on TestEvent {
            param1
            param2
          },
        },
        block {
          number
          hash
        }
      }
    }
    
  • In packages/graph-node, trigger the Test event by calling a example contract method:

    yarn example:test --address $EXAMPLE_ADDRESS
    
    • A Test event shall be visible in the subscription at endpoint.

    • The subgraph entity Category should be updated in the database.

    • An auto-generated diff-staged entry State should be added.

  • Run the query for entity in at the endpoint:

    query {
      category(
        block: { hash: "EVENT_BLOCK_HASH" },
        id: "1"
      ) {
        __typename
        id
        count
        name
      }
    }
    
  • Run the getState query at the endpoint to get the latest State for EXAMPLE_ADDRESS:

    query {
      getState (
        blockHash: "EVENT_BLOCK_HASH"
        contractAddress: "EXAMPLE_ADDRESS"
        # kind: "checkpoint"
        # kind: "diff"
        kind: "diff_staged"
      ) {
        cid
        block {
          cid
          hash
          number
          timestamp
          parentHash
        }
        contractAddress
        data
      }
    }
    
  • diff states get created corresponding to the diff_staged states when their respective blocks reach the pruned region.

  • In packages/graph-test-watcher:

    • After the diff state has been created, create a checkpoint:

      yarn checkpoint create --address $EXAMPLE_ADDRESS
      
      • A checkpoint state should be created at the latest canonical block hash.

      • Run the getState query again at the endpoint with the output blockHash and kind checkpoint.

  • All the State entries can be seen in pg-admin in table state.