how do i copy multiple files in a dockerfile?

Copying multiple files in a Dockerfile is an important way to configure and customize a Docker image for building, shipping, and running a containerized application. But if you're not familiar with how to do this, it can be intimidating to figure out. This article will show you how to copy multiple files in a Dockerfile using four different methods.

The first method of copying files into a Dockerfile is by using the COPY directive. This command copies from either your host directory on the computer which runs the Docker engine or in your working directory which is the build context of your Dockerfile. To copy multiple files within the same directory you can specify them like this:

`COPY "file1" "file2" target/`

This will copy both file1 and file2 into target/ within the container. You can also use wildcards for specific name patterns:

`COPY *.txt target/`

This would copy all .txt files in the working directory into target/. If you want to specify both source and destination paths, simply add them after each other like this:

`COPY /full/path/to/ dir /source/*.* /destination/dir `

The second method of copying multiple files into a Dockerfile is by using the ADD directive. Unlike COPY, ADD allows you to download remote resources via URLs as well as extract compressed (tar, gzip) archives directly inside your container's filesystem. To download multiple files from URLs with ADD, simply list them on separate lines like this:

`ADD http://example.com/a /destination/a ADD http://example.com/b /destination/b `

The third method is by combining multiple COPY or ADD directives within one RUN command. This allows you to bundle many operations into one execution step so that when it runs all necessary operations are executed at once without having too many layers in your image which may slow down your build process or increase image size significantly due to accumulated layers from many times executed similar commands. To combine directives within RUN, use && like this:

`RUN COPY dir1/*.* /destination/dir && ADD http://example.org/dst1 && COPY dir2/*.* /destination2 `

The fourth method of copying multiple files is more manually handled and involves creating an archive such as a tarball on the host system before adding it to your container with either COPY or ADD directive (if downloading remote resource). To create tarball containing several specified directories use command like this:

`tar -cvzf myarchive.tar ./dir1 ./dir2 ./dir3`

See more about dockerfile copy multiple files