Skip to main content

Docker Service

wdio-docker-service is a 3rd party package, for more information please see GitHub | npm

This service is intended for use with WebdriverIO and it helps run functional/integration tests against/using containerized applications. It uses popular Docker service (installed separately) to run containers.

Why use it?​

Ideally your tests would run in some variety of CI/CD pipeline where often there are no "real" browsers and other resources your application depends on. With advent of Docker practically all necessary application dependencies can be containerized. With this service you may run your application container or a docker-selenium in your CI and in complete isolation (assuming CI can have Docker installed as a dependency). Same may apply to local development if your application needs to have a level of isolation from your main OS.

How it works​

Service will run an existing docker image and once its ready, will initiate WebdriverIO tests that should run against your containerized application.

Installation​

Run:

npm install wdio-docker-service --save-dev

Instructions on how to install WebdriverIO can be found here.

Configuration​

By default, Google Chrome, Firefox and PhantomJS are available when installed on the host system. In order to use the service you need to add docker to your service array:

// wdio.conf.js
exports.config = {
   // ...
   services: ['docker'],
   // ...
};

Options​

dockerOptions​

Various options required to run docker container

Type: Object

Default: { options: { rm: true } }

Example:

dockerOptions: {
    image: 'selenium/standalone-chrome',
    healthCheck: 'http://localhost:4444',
    options: {
        p: ['4444:4444'],
        shmSize: '2g'
    }
}

dockerOptions.image​

Docker container name tag. Could be local or from Docker HUB.

Type: String

Required: true

dockerOptions.healthCheck​

Configuration which checks your containers' readiness before initiating tests. Normally this would be a localhost url. If healthCheck is not configured, Webdriver will start running tests immediately after Docker container starts, which maybe too early considering that it takes time for web service to start inside a Docker container.

Type: String|Object

Options for Object use:

  • url - url to an app running inside your container
  • maxRetries - number of retries until healthcheck fails. Default: 10
  • inspectInterval - interval between each retry in ms. Default: 500
  • startDelay - initial delay to begin healthcheck in ms. Default: 0

Example 1 (String): healthCheck: 'http://localhost:4444'

Example 2 (Object):

healthCheck: {
    url: 'http://localhost:4444',
    maxRetries: 3,
    inspectInterval: 1000,
    startDelay: 2000
}

dockerOptions.options​

Map of options used by docker run command. For more details on run command click here.

Any single-letter option will be converted to -[option] (i.e. d: true -> -d).

Any option of two-character or more will be converted to --[option] (i.e. rm: true -> --rm).

For options that may be used more than once (i.e. -e,-add-host, --expose, etc.), please use array notation (i.e. e: ["NODE_ENV=development", "FOO=bar"]).

Type: Object

Example:

options: {
    e: ['NODE_ENV=development', 'PROXY=http://myproxy:80']
    p: ['4444:4444', '5900:5900'],
    shmSize: '2g'
}

dockerOptions.args​

Any arguments you may want to pass into container. Corresponds to [ARG...] in Docker run CLI.

Type: String

dockerOptions.command​

Any command you may want to pass into container. Corresponds to [COMMAND] in Docker run CLI.

Type: String

onDockerReady​

A callback method which is called when Docker application is ready. Readiness is determined by ability to ping healthCheck url.

Type: Function

dockerLogs​

Path to where logs from docker container should be stored

Type: String

Testing Use Cases / Recipes​

Please visit our Wiki for more details.