Hi I have a few questions I would like to ask:
I am confused about ENV instruction are they like packages for your container for example I have a container thats running python and I install python packages like numpy, pandas etc. Are these the environmental variables? Or are environmental variables just any variable that has a set value?
I know that the ONBUILD instruction is used to create an environment where external pieces of code can be added to on of the running image and could be used to create a new image on top of the old image. How would you be able to use it? Can I get an example of the ONBUILD instructs use within the Dockerfile?
In multi stage builds that use two builds you can copy the binary outputs of the first build and place it in the second build. That is the best practice as the OS from the previous build will not be copied thus making total images size very small right?