Here is an example of my nightwatch.json file configured to run parallel tests on Sauce Labs.
{
"src_folders" : ["tests"],
"output_folder" : "reports",
"custom_commands_path" : "custom_commands",
"custom_assertions_path" : "",
"page_objects_path" : "",
"globals_path" : "",
"selenium" : {
"start_process" : false,
"server_path" : "",
"log_path" : "",
"host" : "127.0.0.1",
"port" : 4444,
"cli_args" : {
"webdriver.chrome.driver" : "",
"webdriver.ie.driver" : ""
}
},
"test_workers" : {"enabled" : true, "workers" : "auto"},
"test_settings" : {
"default" : {
"launch_url" : "http://localhost",
"selenium_port" : 80,
"selenium_host" : "ondemand.saucelabs.com",
"silent": true,
"screenshots" : {
"enabled" : false,
"path" : ""
},
"username" : "${SAUCE_USERNAME}",
"access_key" : "${SAUCE_ACCESS_KEY}",
"desiredCapabilities": {
"javascriptEnabled": true,
"acceptSslCerts": true
}
},
"chrome": {
"desiredCapabilities": {
"platform": "XP",
"browserName": "chrome",
"version": "41"
}
},
"firefox" : {
"desiredCapabilities": {
"platform": "XP",
"browserName": "firefox",
"version": "33"
}
},
"internet_explorer_10" : {
"desiredCapabilities": {
"platform": "Windows 7",
"browserName": "internet explorer",
"version": "10"
}
}
}
}
Here is a link to the entire project if you would like to take a look:
https://github.com/saucelabs-sample-test-frameworks/JS-Nightwatch.js
As to your second question. You can see the tests running in the Sauce Labs dashboard. Login at www.saucelabs.com and click on the tests tab in the top left corner.