Gremlin-migrate NPM

gremlin-migrate

Runs gremlin-groovy scripts in-order to upgrade the DB schema

This library can be used to run a sequence of groovy scripts, which are submitted to gremlin-javascript, to perform changes on the target database. Most likely these will be schema changes.

The files are ordered based on semver naming conventions.

Installation

npm install gremlin-migrate --save

Usage

The library exports a function taking configuration parameters and returning an ES6 promise.

import upgradeDbToLatest from 'gremlin-migrate';
...
upgradeDbToLatest(janusGraphDbAddress, portNumber, pathToUpgradeScriptDirectory).then(() => {
    console.log('SUCCESS!');
});

Script library

If you want to use common functions across your groovy files, you can put them in a 'common.groovy' file in the update script directory. These will be available in all of the upgrade files.

Example

0.0.1.groovy (in 'upgradeScripts' subdir)

// I am an example of a comment!
graph.addVertex(label, 'person').property('name', 'john').iterate();
person2 = graph.addVertex(label, 'person');
// NOTE: Don't forget to add the '.next()' else the step won't necessarily take effect!
person2.property('name', 'john').next();
// DON'T put transactions in your upgrade scripts. The scripts are automatically wrapped in a transaction.
// graph.tx().commit();

Example.ts

import { createClient } from 'gremlin';
import upgradeDbToLatest from 'gremlin-migrate';
const client = createClient(8182, '192.168.99.100');

export default class Example {
  public test() {
    client.execute('g.V().hasLabel(\'person\').has(\'name\', \'john\')', (err, results) => {
      console.log('BEFORE UPGRADE: ' + JSON.stringify(results)); // []
      upgradeDbToLatest('192.168.99.100', 8182, __dirname + '/upgradeScripts/').then(() => {
        client.execute('g.V().hasLabel(\'person\').has(\'name\', \'john\')', (err, results) => {
          console.log('AFTER UPGRADE: ' + JSON.stringify(results)); // [ {vertex with person 'john'} ]
        });
      });
    });
  }
}

Tests

The tests are run against a janus-graph/dynamoDb backend configuration to exercise the transaction locking. They spin up docker containers using docker-compose with an empty DB so you will need docker set up on your system.

Run 'docker-compose build' and wait until that finishes (this is a one-off step)

Run 'gulp build' to build the app.

Then run 'gulp test' to run the tests.