Blockchain as a Service:Use filters

Push events by name

Push only Contract events whose smart contract event name is event-create-task.

• Event type: Contract

• Filter: select(.name=="event-create-task")

Pushed data:

{
  "content": "eyJuYW1lIjoidGFzay0xNTgwOTcxODQyOTM3IiwiY3JlYXRvciI6ImUyZWhtZnFhc3RoTVNQLm9jdG9wdXNfMjY4NDJfMTIzNDU2Nzg5MDEyMzQiLCJyZXF1aXJlcyI6WyJlMmVobWZxYXN0aE1TUC5vY3RvcHVzXzI2ODQyXzEyMzQ1Njc4OTAxMjM0Il0sImFwcHJvdmVkIjpudWxsLCJkZXNjcmlwdGlvbiI6IuekuuS+i+S7u+WKoe+8jHJlcXVpcmVzIOmFjee9ruWuoeaJueS7u+WKoeWujOaIkOmcgOimgemCo+S6m+eUqOaIt+WQjOaEj+OAgueUqOaIt+aPj+i/sOS4uiAn57uE57uHTVNQLueUqOaIt+WQjeensCcifQ==",
  "id": "contract-131-ca144c3385f56a429b9e8874173f7c97fbb49de69f931aec583ec50222a3a2ed",
  "instance_id": "csi-e2ehmfqasth-bcw7tzao2dzeo",
  "name": "event-create-task",
  "network": "channel3",
  "platform": "Fabric",
  "type": 8
}

Push valid transactions for a specific contract

Push only valid transactions sent to the taskmgr smart contract.

• Event type: Tx

• Filter: select(.content.to=="taskmgr" and .content.state=="VALID")

Pushed data:

{
  "content": {
    "events": ["event-create-task"],
    "from": "e2ehmfqasthMSP.octopus_26842_12345678901234",
    "id": "3a2e0e375c6ee0d9c6c20d756e787db44d50bfeba51f22d8f262dd1556dedba0",
    "input": "[\"create\",\"task-1580971842937\",\"{\\n \\\"requires\\\": [\\\"e2ehmfqasthMSP.octopus_26842_12345678901234\\\"],\\n \\\"description\\\": \\\"Sample task. Task completion requires the approval of certain users. The user is described as 'Organization MSP. User name'\\\"\\n }\"]",
    "state": "VALID",
    "to": "taskmgr"
  },
  "id": "tx-128-3a2e0e375c6ee0d9c6c20d756e787db44d50bfeba51f22d8f262dd1556dedba0",
  "instance_id": "csi-e2ehmfqasth-bcw7tzao2dzeo",
  "name": "3a2e0e375c6ee0d9c6c20d756e787db44d50bfeba51f22d8f262dd1556dedba0",
  "network": "channel3",
  "platform": "Fabric",
  "type": 2
}

Push a partial event payload

Push only the content field from Contract events named event-create-task, discarding all other fields.

• Event type: Contract

• Filter: select(.name=="event-create-task") | .content

The pushed payload is the raw Base64 string stored in the content field:

"eyJuYW1lIjoidGFzay0xNTgwOTcxODQyOTM3IiwiY3JlYXRvciI6ImUyZWhtZnFhc3RoTVNQLm9jdG9wdXNfMjY4NDJfMTIzNDU2Nzg5MDEyMzQiLCJyZXF1aXJlcyI6WyJlMmVobWZxYXN0aE1TUC5vY3RvcHVzXzI2ODQyXzEyMzQ1Njc4OTAxMjM0Il0sImFwcHJvdmVkIjpudWxsLCJkZXNjcmlwdGlvbiI6IuekuuS+i+S7u+WKoe+8jHJlcXVpcmVzIOmFjee9ruWuoeaJueS7u+WKoeWujOaIkOmcgOimgemCo+S6m+eUqOaIt+WQjOaEj+OAgueUqOaIt+aPj+i/sOS4uiAn57uE57uHTVNQLueUqOaIt+WQjeensCcifQ=="

Extract the write set from a transaction

Push the write set for all keys written by valid taskmgr transactions.

• Event type: Tx

• Filter: select(.content.state=="VALID" and .content.to=="taskmgr") | .content.data.data.actions.[0].payload.action.proposal_response_payload.extension.results.ns_rwset[] | select(.namespace=="taskmgr") | .rwset.writes

The filter drills into the Fabric read-write set and returns only the writes for the taskmgr namespace. Pushed data:

[
  {
    "is_delete": false,
    "key": "\u0000e2ehmfqasthMSP.octopus_26842_12345678901234\u0000task-1581479306267\u0000",
    "value": "eyJuYW1lIjoidGFzay0xNTgwOTcxODQyOTM3IiwiY3JlYXRvciI6ImUyZWhtZnFhc3RoTVNQLm9jdG9wdXNfMjY4NDJfMTIzNDU2Nzg5MDEyMzQiLCJyZXF1aXJlcyI6WyJlMmVobWZxYXN0aE1TUC5vY3RvcHVzXzI2ODQyXzEyMzQ1Njc4OTAxMjM0Il0sImFwcHJvdmVkIjpudWxsLCJkZXNjcmlwdGlvbiI6IuekuuS+i+S7u+WKoe+8jHJlcXVpcmVzIOmFjee9ruWuoeaJueS7u+WKoeWujOaIkOmcgOimgemCo+S6m+eUqOaIt+WQjOaEj+OAgueUqOaIt+aPj+i/sOS4uiAn57uE57uHTVNQLueUqOaIt+WQjeensCcifQ=="
  }
]

Monitor a specific key

Watch for value changes to a specific key in valid taskmgr transactions.

• Event type: Tx

• Filter: select(.content.state=="VALID" and .content.to=="taskmgr") | .content.data.data.actions.[0].payload.action.proposal_response_payload.extension.results.ns_rwset[] | select(.namespace=="taskmgr") | .rwset.writes[] | select(.key=="special_key")

This filter extends the write-set extraction from the previous scenario by matching a single key. Pushed data:

{"is_delete": false, "key": "special_key", "value": "MTA="}

Export transaction data to a database table

Transform blockchain data into an array of objects ready for database insertion. Each object represents one row; the keys are column names.

Expected output format:

[
  {
    "columnName1": "value1",
    "columnName2": "value2",
    "columnName3": "value3"
  }
]

Target table structure:

Primary key: (event_id, namespace, key)

• Event type: Tx

• Filter:

  select(.content.state=="VALID" and .content.to=="taskmgr") | .id as $eventID | .content.id as $txID | .content.from as $creator | content.data.header.channel_header.timestamp as $createTime | .content.data.data.actions.[0].payload.action.proposal_response_payload.extension.results.ns_rwset | ap(.namespace as $namespace | .rwset.writes | map( .event_id = $eventID | .namespace = $namespace | .tx_id = $txID | .create_time = $createTime | .creator = $creator )) | dd

Sample exported data:

[
  {
    "event_id": "tx-128-3a2e0e375c6ee0d9c6c20d756e787db44d50bfeba51f22d8f262dd1556dedba0",
    "namespace": "taskmgr",
    "tx_id": "3a2e0e375c6ee0d9c6c20d756e787db44d50bfeba51f22d8f262dd1556dedba0",
    "is_delete": false,
    "key": "\u0000e2ehmfqasthMSP.octopus_26842_12345678901234\u0000task-1581479306267\u0000",
    "value": "eyJuYW1lIjoidGFzay0xNTgwOTcxODQyOTM3IiwiY3JlYXRvciI6ImUyZWhtZnFhc3RoTVNQLm9jdG9wdXNfMjY4NDJfMTIzNDU2Nzg5MDEyMzQiLCJyZXF1aXJlcyI6WyJlMmVobWZxYXN0aE1TUC5vY3RvcHVzzI2ODQyXzEyMzQ1Njc4OTAxMjM0Il0sImFwcHJvdmVkIjpudWxsLCJkZXNjcmlwdGlvbiI6IuekuuS+i+S7u+WKoe+8jHlcXVpcmVzIOmFjee9ruWuoeaJueS7u+WKoeWujOaIkOmcgOimgemCo+S6m+eUqOaIt+WQjOaEj+OAgueUqOaIt+aPj+i/sOS4uiAn57uE57uHTVNQLueUqOaIt+WQjeensCcifQ==",
    "create_time": "2020-02-06T06:50:42.267092Z",
    "creator": "e2ehmfqasthMSP.octopus_26842_12345678901234"
  }
]