DockerFile Add vs Copy

• ADD has more features than COPYand it is suggested to use COPY.
• COPY only supports the basic copying of local files into the container.
• ADD has some features (like remote URL support)

Docker Add

• src can be a URI
• src can be a tar file. If the compression format is recognized, then the tar file will be automatically unpacked.

Docker Copy

			
					FROM debian:10
ADD  wordpress-latest.tar.gz /app/er
RUN find /app

			
	

			
	
			

		
	

Above will extract the tar.gz package and place it under /app/er.

• ADD allows <src> to be a URL

Docker Copy Command

• You don't need to RUN``mkdir abc for the COPY target, you can COPY . /a/b and docker will create directories for you.
• Directory and Slash. You do need to add slash for command like COPY dir1 /app.
• It will copy all content in dir1 to /app, you won't get path like /app/dir1.
• It is same as COPY dir1 /app/ and COPY dir1/ /app/.
• You CAN NOT copy multiple directories to target directory.

References

• Add or Copy
• Best Practices