dypsilon/AutoWebPerf

AutoWebPerf (AWP)

AutoWebPerf provides a flexible and scalable framework for running web performance audits with arbitrary audit tools like WebPageTest and PageSpeedInsights. This library enables developers to collect metrics consistently and store metrics to a preferred data store such as local JSON files, Google Sheets, BigQuery, or an in-house SQL database.

Check out https://web.dev/autowebperf for introduction.

How it works

AutoWebPerf takes a list of Tests from an arbitrary data store platform, such as local JSONs, Google Sheets, BigQuery, or a self-hosted SQL database. With the list of Tests, it executes audits based on each Test config, collects metrics from individual data sources into a list of Results.

The process of running an audit through an measurement tool (e.g. WebPageTest) is defined in the individual Gatherer. The logic of reading and writing with a data platform (e.g. local JSON) is implemented in a Connector.

Feature highlights

• A library of web audit automation that can be plugged-in to any platforms, like Google Sheets, GCP App Engine, or simply a cron job that writes to JSON file.
• Providing the ability to run recurring tests with customizable frequency (e.g. daily, weekly, monthly, etc), network conditions, and other audit configs, etc.
• Metric gatherers are designed as modules that are decoupled with the output data format and automation logic.
• Connector modules are designed to read Test list and write audit results to specific data format or platforms. e.g. a connector for CSV files. (See src/connectors/csv-connector for details)

How does this compare to the rest of Google's speed measurement tools?

AutoWebPerf serves as a performance audit aggregator that automates the process of performance audit and metrics collection through multiple speed measurement tools including WebPageTest, PageSpeedInsights, and Chrome UX Report. As each individual speed measurement tool provides audit metrics, AutoWebPerf aggregates the results and writes to any preferred data storage platform, such as local JSONs, cloud-based database, or GoogleSheets.

Quickstart

First, clone AWP repo and run npm install:

git clone https://github.com/GoogleChromeLabs/AutoWebPerf.git
npm install

Once finished, check the install by running a single test with the following command:

./awp run examples/tests.json output/results.json

This command uses the example file in examples/tests.json and returns the results to output/results.json.

To start recurring tests, you'll need to include a recurring.frequency property in the test file and set the next trigger in the test file. To setup the next trigger time and to run a one-off test, use this command after adding the recurring.frequency property to your tests:

./awp recurring examples/tests-recurring.json output/results.json

If this was successful, the trigger time will have updated base on your chosen frequency, and a result would have been written to output/results.json.

Once the trigger time is correctly set, you can have your tests auto-run on the next triger time with the continue command:

./awp continue examples/tests-recurring.json output/results.json

This will automatically run each test at the frequency specified. More information can be found below in the "Run recurring tests" section below.

More Examples

Single URL: To test a single URL through PageSpeedInsights:

./awp run url:https://www.thinkwithgoogle.com/ json:output/results.json

Pick Gatherer: to test a single URL with a specific gatherer like PageSpeedInsights or WebPageTest:

./awp run --gatherers=psi url:https://web.dev json:output/results.json

CSV file: To run tests defined in a CSV file and write results to a JSON file:

./awp run csv:examples/tests.csv json:output/results.json

PageSpeedInsights API: To run PageSpeedInsights tests with an API Key:

PSI_APIKEY=SAMPLE_KEY ./awp run examples/tests.json output/results.json

WebPageTest API: To run WebPageTest tests:

WPT_APIKEY=SAMPLE_KEY ./awp run examples/tests-wpt.json output/results.json

Override vs. Append: To run tests and override existing results in the output file

./awp run examples/tests.json output/results.json --override-results

Using AWP with Node CLI

Run tests

You can run the following anytime for printing CLI usages:

./awp --help

To run tests, you can run the following CLI command with given Tests JSON, like examples/tests.json, which contains an array of tests. You can check out the examples/tests.json for the data structure of Tests.

./awp run examples/tests.json output/results.json

This will generate the result object(s) in the given path to results.json.

By default, AWP will use JSON as the default connector for both reading tests and writing results. Alternatively, you can specify a different connector in the format of <connector>:<path>.

E.g. to run tests defined in CSV and write results in JSON:

./awp run csv:examples/tests.csv json:output/results.csv

Retrieve test results

For some audit platforms like WebPageTest, each test may take a few minutes to fetch actual results. For these type of asynchronous audits, each Result will stay in "Submitted" status. You will need to explicitly retrieve results later.

Run the following to retrieve the final metrics of results in the results.json.

./awp retrieve examples/tests.json output/results.json

This will fetch metrics for all audit platforms and update to the Result object in the output/results.json. You can check out examples/results.json for details in Result objects.

Run recurring tests

If you'd like to set up recurring tests, you can define the recurring object that contains frequency for that Test.

./awp recurring examples/tests-recurring.json output/results.json

This will generate the Result object in the results.json and updates the next trigger time to its original Test object in the tests.json. E.g. the updated Test object would look like the following, with the updated nextTriggerTimestamp.

{
  "label": "web.dev",
  "url": "https://web.dev",
  "recurring": {
    "frequency": "Daily",
    "nextTriggerTimestamp": 1599692305567,
    "activatedFrequency": "Daily"
  },
  "psi": {
    "settings": {
      "locale": "en-GB",
      "strategy": "mobile"
    }
  }
}

The nextTriggerTimestamp will be updated to the next day based on the previous timestamp. This is to prevent repeated runs with the same Test and to guarantee that this Test is executed only once per day.

Set up a cron job to run recurring tests

In most Unix-like operating system, you can set up a cron job to run the AWP CLI periodically.

For example, in macOS, you can run the following commands to set up a daily cron job with AWP:

# Edit the cronjob with a text editor.
EDITOR=nano crontab -e

Add the following line to the crontab for a daily run at 12:00 at noon. Note that this is based on the system time where it runs AWP.

0 12 * * * PSI_APIKEY=SAMPLE_KEY cd ~/workspace/awp && ./awp run examples/tests.json csv:output/results-recurring.csv

Run tests with extensions

An extension is a module to assist AWP to run tests with additional process and computation. For example, budgets extension is able to add performance budgets and compute the delta between the targets and the result metrics.

To run with extensions:

./awp run examples/tests.json output/results.json --extensions=budgets

Tests and Results

Define the Tests

The list of tests is simply an array of Tests objects, like the sample Tests below. Or check out src/examples/tests.js for a detailed example of Tests list.

[{
  "label": "Test-1",
  "url": "example1.com",
  "webpagetest": {
    ...
  }
}, {
  "label": "Test-2",
  "url": "example2.com",
  "psi": {
    ...
  }
}]

Each Test object defines which audits to run by defining gatherers property. For example, the first Test has a webpagetest property which defines the configuration of running a WebPageTest audit. The second Test has a psi property that defines how to run PageSpeedInsights audit.

Generate the Results

After running tests, a list of Results is generated like below. Each Result contains its corresponding metrics to the predefined gatherers such as WebPageTest and PageSpeedInsights. See the example below.

[{
  "label": "Test-1",
  "url": "example1.com",
  "webpagetest": {
    "metrics": {
      FirstContentfulPaint: 900,
      ...
    }
  }  
}, {
  "label": "Test-2",
  "url": "example2.com",
  "psi": {
    "metrics": {
      FirstContentfulPaint: 900,
      ...
    }
  }  
}]

Environmental Variables

TBD

Gatherers

AWP supports the following audit gatherers. Please check out the corresponding documentations for details.

WebPageTest

The WebPageTest gatherer runs Tests through either the public WebPageTest endpoints or a custom private WebPageTest instance.

See docs/webpagetest.md for more details for the usage of WebPageTest gatherer.

PageSpeed Insights

The PageSpeed Insights gatherer runs Tests through the public PageSpeed Insights API.

See docs/psi.md for more details for the usage of PSI gatherer.

Chrome UX Report API (CrUX API)

TBD

Chrome UX Report History (CrUX via BigQuery)

TBD

Design

AWP is designed with modules, including modules for running audits with WebPageTest, PageSpeedInsights, or other tools, and modules for reading/writing data from data platforms such as JSON, GoogleSheets or a Cloud service.

In a high-level view, there are three types of modules:

• Gatherer - A Gatherer runs audits and generates metrics.
• Connector - A Connector reads test configs from and writes results to a data platform, such as a local JSON file or with Google Sheets.
• Extension - An Extension adds additional metrics or information, either before or after running audits.

The AWP engine uses two major JavaScript Object structures for running audits and collecting metrics.

• Test - An object that contains the audit configuration for one test task, such as URL, audit methods, or extension config. You can refer to examples/tests.json for an actual Test object.
• Result - An object that contains audit configuration, metrics and overall status. You can refer to examples/results.json for an actual Result object.

Audit steps

In order to deal with asynchronous audit tool like WebPageTest, AWP breaks the audit cycle into three steps of actions:

• Run - This action takes a list of Tests and generates a list of Results objects.
• Recurring - Similar to Run, this action takes a list of Tests, generates a list of Results, and updates nextTriggerTimestamp for each recurring Test. This action is useful when running with periodic or timer-based tasks such as cron job.
• Retrieve - This action scans the list of Results, and collects metrics when the results are not in Retrieved status.

AWP Config

To set up modules and their configurations, an overall AWP Config is required as a JavaScript Object.

AWP Config has the following required properties:

• connector: The name of connector.
• helper: A helper for a specific connector, including API Handler and other helper functions, which will be used in gatherers and extensions.
• dataSources: An array of audit sources, such as webpagetest or psi. Each of the data source needs to have a corresponding Gatherer file in the src/gatherers folder.
• extensions: An array of extensions. Each extension needs to have a corresponding Extension file in src/extensions.

Other optional properties:

• verbose: Whether to print verbose messages.
• debug: Whether to print debug messages.

The following config example comes from the examples/awp-config.js:

{
  connector: 'JSON',
  helper: 'Node',
  dataSources: ['webpagetest'],
  json: { // Config for JSON Connector.
    tests: 'tests.json',
    results: 'results.json',
  },
  extensions: [
    'budgets',
  ],
  budgets: { // Config for Budgets extension.
    dataSource: 'webpagetest',
  },
  verbose: true,
  debug: false,
}

With the example config above, it will use JSON connector which reads and writes Tests and Results as JSON files. See examples/tests.json and examples/results.json for examples.

In addition to fundamental properties, there are a few additional properties used by modules:

• json property as the configuration for JSONConnector.
• budgets property as the configuration for BudgetsExtension

Usage of AutoWebPerf core

Examples of creating a new instance of AWP:

let awp = new AutoWebPerf({
  connector: 'JSON',
  helper: 'Node',
  dataSources: ['webpagetest'],
  extensions: extensions,
  json: { // Config for JSON connector.
    tests: argv['tests'],
    results: argv['results'],
  },
  verbose: verbose,
  debug: debug,
});

To submit all tests:

awp.run();

To submit specific tests using filters: This will run the test which has id=1 and selected=true properties.

awp.run({
  filters: ['id="1"', 'selected'],
});

To retrieve all pending results, filtering with status !== "Retrieved".

awp.retrieve({
  filters: ['status!=="Retrieved"'],
});

• For more advanced usage of PatternFilter, please check out src/utils/pattern-filter.js with more examples.

To run recurring tests:

// This will run the actual audit and update the nextTriggerTimestamp.
awp.recurring();

To run tests with specific extensions:

// This will override the extension list defined in the awpConfig.
awp.run({
  extensions: ['budgets']
})

Gatherer Modules

A Gatherer class extends src/gatherers/gatherer.js and overrides the following methods:

• constructor(config, apiHelper, options):

  • config: The config defined in a property with this gatherer's name in the AWP config. Some audit tools like WebPageTest or PageSpeedInsights require API keys. The API key for the gatherer is located in the config.apiKey.
  • options: Additional settings like verbose and debug.

• run(test, options):

  • test: A Test object for this audit run. The data required for this gatherer (e.g. settings or metadata) will be in the property with the gatherer's name. E.g. the data for WebPageTest will be in webpagetest of this Test object.
  • options: Additional settings.

• retrieve(result, options):

  • result: A Result object to retrieve metrics with. The data required for this gatherer will be in the property with the gatherer's name. E.g. the data and metrics will be in webpagetest of this Result object.
  • options: Additional settings like verbose and debug.

Connector Modules

A Connector class extends src/connectors/connector.js and overrides the following methods:

• constructor(config, apiHandler):

  • config: The config defined in a property with this connector's name in the AWP config.
  • apiHandler: The API handler instance used for making API calls.

• getConfig(): The method to return the Connector's additional config object. This config object depends on where this Connector stores its additional settings including API keys for gatherers. For example, JSONConnector uses the tests.json and reads additional settings from the config property, including API keys for each gatherers.

• getTestList(options): The method to return the list of Tests as an array.

• updateTestList(newTests, options): The method to update Tests list, given the list of new Tests.

• getResultList(options): The method to return the list of Results as an array.

• appendResultList(newResults, options): The method to append new Results to the end of the current Results list.

• updateResultList(newResults, options): The method to update existing Results in the current Results list.

Extension Modules

A Extension class extends src/extensions/extension.js and overrides the following methods:

• constructor(config):
  • config: The config defined in a property with this extension's name in the AWP config.
• beforeRun(context): The method before executing Run step for a Test.
  • context.test: The corresponding Test object.
• afterRun(context): The method after executing Run step for a Test.
  • context.test: The corresponding Test object.
  • context.result: The corresponding Result object.
• beforeAllRuns(context): The method before executing Run step.
  • context.tests: All Test objects in this Run.
• afterAllRuns(context): The method after executing Run step.
  • context.tests: All Test objects in this Run.
  • context.results: All Result objects in this Run.
• beforeRetrieve(context): The method before executing Retrieve step for a Result.
  • context.result: The corresponding Result object.
• afterRetrieve(context): The method after executing Retrieve step for a Result.
  • context.result: The corresponding Result object.
• beforeAllRetrieves(context): The method before executing Retrieve step.
  • context.result: The corresponding Result object.
• afterAllRetrieves(context): The method after executing Retrieve step.
  • context.result: The corresponding Result object.

Test Object

A standard Test object contains the following properties:

(You can refer to examples/tests.json for an example.)

• selected : Whether to perform Run for this Test.
• label : Name of this Test.
• url : URL to audit.
• recurring: Settings for recurring audit.
  • frequency : The frequency string defined in src/common/frequency.js. E.g. 'Daily', 'Weekly' or 'Monthly'.

Gatherer-specific settings will be in their own property with the Gatherer's name in lower case. For example, the settings for WebPageTests will be:

• webpagetest
  • settings: Setting object contains audit location, connection, etc.
  • metadata: Metadata object contains WebPageTests's ID, JSON URL, etc.

Result Object

A standard Result object contains the following properties:

• selected : Whether to perform Retrieve for this Result.
• id : Auto-generated unique ID for this Result.
• type : Single or Recurring audit.
• status : Submitted, Retrieved or Error. Refer to src/common/status.js for details.
• label : String label for this Result. This label inherits from its original Test object.
• url : Audited URL.
• createdTimestamp : When this Result is created.
• modifiedTimestamp : When this Result is last modified.

Standardized Metrics

All metric names used in AWP are required to follow the names, case sensitive. See the full list of standardized metrics in src/common/metrics.js

• Timing metrics

  • TimeToFirstByte
  • FirstPaint
  • FirstMeaningfulPaint
  • FirstContentfulPaint
  • VisualComplete
  • SpeedIndex
  • DOMContentLoaded
  • LoadEvent
  • TimeToInteractive
  • TotalBlockingTime
  • FirstCPUIdle
  • FirstInputDelay
  • LargestContentfulPaint

• Resource Size

  • HTML
  • Javascript
  • CSS
  • Fonts
  • Images
  • Videos

• Resource Count

  • DOMElements
  • Connections
  • Requests

• Resource Scores

  • Performance
  • ProgressiveWebApp

Source Folder Structure

All source codes for major functions are located in src folder. Files are organized into the following subfolders:

• common: Common classes and definitions, such as Status, Frequency, Metrics, etc.
• connectors: Connector classes.
• extensions: Extension classes.
• gatherers: Gatherer classes.
• utils: Utilities and tools.

Unit Test

Run the following commands to run unit test:

npm test

To run individual test spec, you can install Jest NPM module to your local machine:

npm install -g jest
jest test/some-module.test.js

Unit Test Design

The Unit Test is based on Jest unit test framework. All unit tests are located in the ./test folder, and are organized into its own corresponding subfolders, as the same structure as in the src folder.