I just learned the next dockerfile, and want to make a mirror image, including nginx and lua environments. I don’t know how to write the dockerfile. I feel there are two ways:
First, install nginx and lua based on ubuntu image
FROM ubuntu
RUN apt－get install nginx
RUN apt－get install lua
Second, install lua based on nginx image
FROM nginx
RUN apt－get install lua

Please tell me what is the correct posture, please give specific writing examples, thank you!