Write an AWS Lambda to query a Neptune DB with openCypher using aws-sdk v3 - aws-lambda

Question

I have a Lambda with Node.js 18 runtime, in which I would like to send an openCypher query to an AWS Neptune DB.
My Lambda is using an IAM role with these policies:
NeptuneFullAccess
AWSLambdaBasicExecutionRole
AmazonSSMReadOnlyAccess
(The last policy will be used to fetch the Neptune endpoint from the SSM parameters store later).
I'm trying to find the aws-sdk/client-neptune method to submit the query, but I couldn't find any in the library # GitHub.
This is frustrating, as I'm struggling for days to find a simple way to use the aws-sdk V3 with a Nodejs 18 Lambda to do a simple task of querying the Neptune DB.
Here my current skeleton of the Lambda:
import { NeptuneClient } from "#aws-sdk/client-neptune";
export async function handler() {
const neptuneEndpoint = "https://<my-db-instance>.us-east-1.neptune.amazonaws.com";
const neptune = new NeptuneClient({
endpoint: neptuneEndpoint,
region: "us-east-1",
});
const cypher = `MATCH (n) RETURN n`;
const query = {
Gremlin: cypher
};
const command = {
GremlinCommand: query,
};
const result = await neptune.send(command).promise();
console.log(result);
return result;
}
Can anyone please help me turn this into a working Lambda?

Answer 1

The client you are using only exposes Control Plane actions, such as Creating/Modifying cluster instances, and is not meant to be used to query Neptune. For openCypher, the recommendation is to query Neptune using the HTTPS endpoint as described here.

Answer 2

I have created a sample Neptune db and sample lambda. I have also used Lambda layers to install necessary gremlin dependencies. Please find the lambda code and lambda response screenshots below
Lambda code
const gremlin = require('gremlin');
const DriverRemoteConnection = gremlin.driver.DriverRemoteConnection;
const Graph = gremlin.structure.Graph;
dc = new DriverRemoteConnection('wss://<db cluster name>.ap-south-1.neptune.amazonaws.com:8182/gremlin',{});
const graph = new Graph();
const g = graph.traversal().withRemote(dc);
const { t: { id } } = gremlin.process;
const { cardinality: { single } } = gremlin.process;
const createVertex = async (vertexId, vlabel) => {
const vertex = await g.addV(vlabel)
.property(id, vertexId)
.property(single, 'name', 'lambda')
.property('lastname', 'Testing') // default database cardinality
.next();
return vertex.value;
};
createVertex('sampledata1','testing')
exports.handler = async(event) => {
try {
const results = await g.V().hasLabel("sampledata1").properties("name")
console.log("--------",results);
return results
} catch (error) {
// error handling.
console.log("---error---",error);
return error
}
};
Note:
Replace db endpoint with your own db endpoint
Sample response from lambda
Lambda response screenshot