Referenced and Thanks to : https://medium.com/@aimvec/high-performance-mocking-for-load-testing-bd6d69610cc9
install docker
install caddy server (MacOS: brew install caddy)
cd path/to/target/dir/with/dockerfile
docker build . -t dummymock
docker images
docker run -d --rm -p 9091:80 dummymock
docker ps -a | grep dummymock
caddy start
start to send request to dummymock service and customize the API response time(in milliseconds):
http://localhost:8020/?duration=300
P.S.
Removed unused docker images
docker rmi -f $(docker images -f "dangling=true" -q)
You need to rebuild your docker image if you want to change your response.json file