This is my first post so please have mercy. I'm writing this hoping that I will save some time for whoever tries to follow me into the madness of running selenium tests in a headless browser from jMeter in a docker container, thus enabling performance. 

I don't like writing stories so I'm keeping this a list/point format so it's easy to understand and find the things I though are useful.  You can find the script attached and details on how it works bellow. 

 - Selenium commands are written in JSR samplers in jMeter 

 - Pass the browser as object between samplers 

 - Use jMeter logging to log progress, errors and more

 - Install jMeter and its plugin manager

 - Install the Selenium Support plugin

 - Pass the browser as object between sampler:

WebDriver driver = vars.getObject("driver");

Ok so this section is what I believe is most helpful and I want to share with you. I encountered a lot of problems in my app (checking the jmx will prove that but these are the most helpful tips I can offer anyone)

Require a JavascriptExecutor to be defined. The objects can be passed between samplers. 

import org.openqa.selenium.JavascriptExecutor;

js.executeScript("arguments[0].scrollIntoView({block: 'center'});", driver.findElement(By.xpath("(//li[@id='tui-pin']//i[@class='fas fa-trash mr-1'])[2]")));

js.executeScript("window.scrollTo(0,0)"); //Scroll to top

this.takeSnapShot(driver, vars.get("pic_location")+"HomePage.png") ;

Sometimes a button would simply not be clickable so as a workaround implement an action so it simulates a mouse click. Requires an action to be defined. 

import org.openqa.selenium.interactions.Actions;

 - A final check in jMeter

In case a selenium action fails the whole sampler is marked as failure. but test might fail due to your assertions. In case you don't want to search jmeter logs for multiple error strings I added a log in case sampler is marked as failure in a JSR Assertion Sampler added as a child to the JSR Sampler running the selenium scripts.  

MST-ALL Master BKP.jmx