Using Selenium Standalone, ChromeDriver etc are great ways to run automated tests on your machine or CI, but they use the locally installed browser to execute the tests. What happens if you don't have that browser on your machine? Or if you want to test a different version of the browser than you have installed? Selenoid to the rescue!
From Aerokube Selenoid Selenoid is "A lightning fast Selenium protocol implementation running browsers in Docker containers"
As long as you have docker installed, you can run any of the available images provided free of charge by Selenoid.
Note: If you use this service you don't need any other driver services (e.g. wdio-chromedriver-service) anymore. All browsers supported by selenoid can be started using this service.
Note: You might notice we pull the version of selenoid with VNC enabled. To take advantage of this, please check out the wdio-selenoid-ui-service for more information.
- Quickly change browser versions without having to install any software
- Consistent execution environment between local and CI
- Video Recording of all tests
- VNC "Live View" support to view the tests as they run, even on a headless ci server
- Specify any screen resolution and timezone without changing your system setup
Before starting make sure you have Docker installed
The easiest way is to keep wdio-selenoid-standalone-service as a devDependency in your package.json.
{
"devDependencies": {
"wdio-selenoid-standalone-service": "^1.0.0"
}
}You can simple do it by:
npm install wdio-selenoid-standalone-service --save-devor
yarn add wdio-selenoid-standalone-service --devInstructions on how to install WebdriverIO can be found here.
In order to use the service you need to add selenoid-standalone to your service array and change the default wdio path prop to match selenoid
export.config = {
// ...
path: 'wd/hub'
services: [
['selenoid-standalone', { pathToBrowsersConfig: './browsers.json' }] // path relative to process.cwd()
],
// ...
};Next you need to create the browsers.json file which is a configuration file that tells Selenoid which browsers you want to support. An example for chrome 88, 87 and FireFox 85 would be:
{
"chrome": {
"default": "88.0",
"versions": {
"88.0": {
"image": "selenoid/vnc:chrome_88.0",
"port": "4444",
"path": "/"
},
"87.0": {
"image": "selenoid/vnc:chrome_87.0",
"port": "4444",
"path": "/"
}
}
},
"firefox": {
"default": "85.0",
"versions": {
"85.0": {
"image": "selenoid/vnc:firefox_85.0",
"port": "4444",
"path": "/wd/hub"
}
}
}
}The default value for each browser is what browser will be run if you do not supply a browserVersion prop within your capabilities.
Note: Pay attention to the path as these can change depending on the browser image being used
More information about browsers.json can be found here
The following options can be added to the service options. They are all optional
Automatically pull docker images added to browsers.json that do not exist on your system
Type: Boolean
Default: false
When this service runs the selenoid docker image it will give it a custom name. If you want to use your own name, you can override it here
Type: String
Default: wdio_selenoid
As this service should be the only browser driver needed, if there is a problem starting it will issue a SevereServiceError exception and stop wdio from running. If you want to disable this behavior set this to false
Type: Boolean
Default: true
If you want to always use a specific version of Selenoid, you can fix the version here. If unset, this service will use the image tagged with latest-release
Type: String
Default: latest-release
Port which the Selenoid container should use to accept incoming connections
Type: Number
Default: 4444
The following options are experimental and can cause unexpected problems. Use with caution
Any additional arguments you want to pass to docker run when starting the container. docker run options
Type: String[]
Default: null
Any additional arguments you want to pass to selenoid when starting the container. docs
Type: String[]
Default: null
export.config = {
// ...
path: 'wd/hub'
services: [
[
'selenoid-standalone', {
pathToBrowsersConfig: './browsers.json',
skipAutoPullImages: 'false',
customSelenoidContainerName: 'wdio-selenoid',
terminateWdioOnError: true,
selenoidVersion: 'latest-version',
port: 4444,
dockerArgs: ['-rm'],
selenoidArgs: ['-limit', '10'],
},
],
],
// ...
};As the browsers are now running inside a docker container, localhost is local to the container. If you want to access localhost of the docker host, change the url from localhost to host.docker.internal. Example https://localhost:3000 becomes https://host.docker.internal:3000
RequestError: Unexpected token Y in JSON at position 0 in "http://localhost:4444/session"
You need to set path: 'wb/hub' in your wdio.conf.js file as wdio will default to a path of / which Selenoid doesn't
browsers.json is referencing a browser that is not supported by selenoid. Supported list can be found here
Update the browsers.json file and change the image name to also include your mirror and this will be passed to docker when selecting the image
{
"chrome": {
"default": "88.0",
"versions": {
"88.0": {
"image": "my-docker-mirror.internal/selenoid/vnc:chrome_88.0",
"port": "4444",
"path": "/"
}
}
}
}