I have UI project which is using GRUNT to perform build and tests. When I try to invoke tests within concourse task which resource image I should use where grunt is already installed. I am getting this below error now.
/bin/bash: line 4: grunt: command not found
You can use any OCI-compatible image that has grunt preinstalled. Alternatively, make your own image and push it to a repository like dockerhub. As yet another alternative you could use a base image for your task and install grunt every time (though this is slower).
TLDR: Concourse does not provide task images and you need to use your own.