Sequelize.js

Introduction

This package is in the form of Sequelize.Client.prototype.query wrapper whose purpose is to augment a SQL statement right before execution, with information about the controller and user code to help correlate them with SQL statements emitted by Sequelize.js.

Besides plain sequelize.js wrapping, we also provide a wrapper for the following frameworks:

Requirements

Installation

We can add integration into our applications in the following ways:

Manually

Please read installing sqlcommenter-nodejs from source

Package manager

Add to your package.json the dependency

{
    "@google-cloud/sqlcommenter-sequelize": "*"
}

and then run npm install to get the latest version or

npm install @google-cloud/sqlcommenter-sequelize --save

Usage

Plain sequelize wrapper

const {wrapSequelize} = require('@google-cloud/sqlcommenter-sequelize');
const Sequelize = require('sequelize');

// Create the sequelize client.
const sequelize = new Sequelize(options);

// Finally wrap the sequelize client.
wrapSequelize(sequelize);

Express middleware

This wrapper/middleware can be used as is or better with express.js

const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const Sequelize = require('sequelize');
const sequelize = new Sequelize(options);
const app = require('express')();

// Use the sequelize+express middleware.
app.use(wrapSequelizeAsMiddleware(sequelize));

Fields

In the database server logs, the comment’s fields are:

Field Format Description Example
client_timezone <string> URL quoted name of the timezone used when converting a date from the database into a JavaScript date '+00:00'
db_driver <sequelize> URL quoted name and version of the database driver db_driver='sequelize'
route <the route used> URL quoted route used to match the express.js controller route='%5E%2Fpolls%2F
traceparent <traceparent header> URL quoted W3C traceparent header traceparent='00-3e2914ebce6af09508dd1ff1128493a8-81d09ab4d8cde7cf-01'
tracestate <tracestate header> URL quoted W3C tracestate header tracestate='rojo%253D00f067aa0ba902b7%2Ccongo%253Dt61rcWkgMzE'

Options

When creating the middleware, one can optionally configure the injected comments by passing in the include and options objects:

wrapMainSequelizeAsMiddleware(Sequelize, include={...}, options={...});
include config

A map of values to be optionally included in the SQL comments.

Field On by default
client_timezone
db_driver
route
traceparent
tracestate
options config

A configuration object specifying where to collect trace data from. Accepted fields are: TraceProvider: Should be either OpenCensus or OpenTelemetry, indicating which library to collect trace context from.

Field Possible values
TraceProvider OpenCensus or OpenTelemetry
Options examples
wrapMainSequelizeAsMiddleware(
    Sequelize,
    include={ traceparent: true, tracestate: true },
    options={ TraceProvider: 'OpenTelemetry' }
);
wrapMainSequelizeAsMiddleware(Sequelize, include={client_timezone: true});
wrapMainSequelizeAsMiddleware(Sequelize, include={route: true});
wrapMainSequelizeAsMiddleware(Sequelize, include={db_driver: true});
// Manually set all the variables.
wrapMainSequelizeAsMiddleware(
    Sequelize,
    include={
        client_timezone: true,
        db_driver: true,
        route: true,
        traceparent: true,
        tracestate: true,
    },
    options={ TraceProvider: 'OpenTelemetry' }
);

End to end examples

Check out a full express + opentelemetry example here.

Source code

// In file app.js.
const tracing = require('@opencensus/nodejs');
const {B3Format} = require('@opencensus/propagation-b3');
const {ZipkinTraceExporter} = require('@opencensus/exporter-zipkin');
const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const Sequelize = require('sequelize');
const express = require('express');

const exporter = new ZipkinTraceExporter({
    url: process.env.ZIPKIN_TRACE_URL || 'localhost://9411/api/v2/spans',
    serviceName: 'trace-542'
});

const b3 = new B3Format();
const traceOptions = {
    samplingRate: 1, // Always sample
    propagation: b3,
    exporter: exporter
};

// start tracing
tracing.start(traceOptions);

// Using a connection URI
const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname');

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the sequelize+express middleware with trace attributes 
app.use(wrapSequelizeAsMiddleware(
    sequelize,
    { traceparent: true, tracestate: true, route: false },
    { TraceProvider: "OpenCensus" },
));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    sequelize.query('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));
// In file app.js.
const { NodeTracerProvider } = require("@opentelemetry/node");
const { BatchSpanProcessor } = require("@opentelemetry/tracing");
const {
  TraceExporter,
} = require("@google-cloud/opentelemetry-cloud-trace-exporter");

const tracerProvider = new NodeTracerProvider();
// Export to Google Cloud Trace
tracerProvider.addSpanProcessor(
  new BatchSpanProcessor(new TraceExporter({ logger }), {
    bufferSize: 500,
    bufferTimeout: 5 * 1000,
  })
);
tracerProvider.register();

// OpenTelemetry initialization should happen before importing any libraries
// that it instruments
const { Sequelize } = require("sequelize");
const {
  wrapSequelizeAsMiddleware,
} = require("@google-cloud/sqlcommenter-sequelize");

const sequelize = new Sequelize("postgres://user:pass@example.com:5432/dbname");

const express = require("express");
const app = express();
const port = process.env.APP_PORT || 3000;

// SQLCommenter express middleware injects the route into the traces
app.use(
  wrapSequelizeAsMiddleware(
    sequelize,
    {
      client_timezone: true,
      db_driver: true,
      route: true,
      traceparent: true,
      tracestate: true,
    },
    { TraceProvider: "OpenTelemetry" }
  )
);

app.get("/", (req, res) => res.send("Hello, sqlcommenter-nodejs!!"));
app.get("^/polls/:param", function (req, res) {
  sequelize
    .query("SELECT * from polls_question")
    .then(function (polls) {
      const blob = JSON.stringify(polls);
      res.send(blob);
    })
    .catch(function (err) {
      console.log(err);
      res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));
// In file app.js.
const Sequelize = require('sequelize');
const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const express = require('express');

// Using a connection URI
const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname');

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the sequelize+express middleware with route
app.use(wrapSequelizeAsMiddleware(sequelize, {route: true}));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    sequelize.query('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));
// In file app.js
const Sequelize = require('sequelize');
const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const express = require('express');

// Using a connection URI
const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname');

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the sequelize+express middleware with db driver and timezone
app.use(wrapSequelizeAsMiddleware(sequelize, {
    db_driver: true, 
    client_timezone: true
}));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    sequelize.query('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));
// In file app.js.
const tracing = require('@opencensus/nodejs');
const {B3Format} = require('@opencensus/propagation-b3');
const {ZipkinTraceExporter} = require('@opencensus/exporter-zipkin');
const Sequelize = require('sequelize');
const {wrapSequelizeAsMiddleware} = require('@google-cloud/sqlcommenter-sequelize');
const express = require('express');

const exporter = new ZipkinTraceExporter({
    url: process.env.ZIPKIN_TRACE_URL || 'localhost:9411/api/v2/spans',
    serviceName: 'trace-542'
});

const b3 = new B3Format();
const traceOptions = {
    samplingRate: 1, // Always sample
    propagation: b3,
    exporter: exporter
};

// start tracing
tracing.start(traceOptions);

// Using a connection URI
const sequelize = new Sequelize('postgres://user:pass@example.com:5432/dbname');

const app = express();
const port = process.env.APP_PORT || 3000;

// Use the sequelize+express middleware with all attributes set
app.use(wrapSequelizeAsMiddleware(
    sequelize,
    {
        traceparent: true,
        tracestate: true,

        // Optional
        route: false,
        db_driver: false,
        client_timezone: false
    },
    {
        TraceProvider: "OpenCensus",
    },
));

app.get('/', (req, res) => res.send('Hello, sqlcommenter-nodejs!!'));
app.get('^/polls/:param', function(req, res) {
    sequelize.query('SELECT * from polls_question').then(function(polls) {
        const blob = JSON.stringify(polls);
        res.send(blob);
    }).catch(function(err) {
        console.log(err);
        res.send(500);
    });
});
app.listen(port, () => console.log(`Application listening on ${port}`));

which after running by

$ node app.js 
Application listening on 3000

Results

On making a request to that server at http://localhost:3000/polls/1000, the PostgreSQL logs show:

2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*traceparent='00-11000000000000ff-020000ee-01',tracestate='brazzaville=t61rcWkgMzE,rondo=00f067aa0ba902b7'*/
2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*route='%5E%2Fpolls%2F%1000'*/
2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*client_timezone:'%2B00%3A00',db_driver='sequelize%3A0.0.1'*/
2019-06-03 14:32:10.842 PDT [32004] LOG:  statement: SELECT * from polls_question 
/*client_timezone:'%2B00%3A00',db_driver='sequelize%3A0.0.1',route='%5E%2Fpolls%2F%1000',traceparent='00-11000000000000ff-020000ee-01',tracestate='brazzaville=t61rcWkgMzE,rondo=00f067aa0ba902b7'*/

References

Resource URL
@google-cloud/sqlcommenter-sequelize on npm https://www.npmjs.com/package/@google-cloud/sqlcommenter-sequelize
express.js https://expressjs.com/