What is the difference between the 'COPY' and 'ADD' commands in a Dockerfile?

What is the difference between the COPY and ADD commands in a Dockerfile, and when would I use one over the other? COPY <src> <dest> The COPY instruction will copy new files from <src> and add them to the container's filesystem at path <dest> ADD <src> <dest> The ADD instruction will copy new files from <src> and add them to the container's filesystem at path <dest>.

[takahiroki]

copy と add の仕様が、多少変遷してきているっぽい。簡単にいうと、 add には tar 展開機能があり、その場合に限り、 add の方が preferrable らしい。 otherwise copy preferred.