How to copy multiple files in one layer using a Dockerfile?

Question

My Dockerfile has four COPY layers:

COPY README.md ./
COPY package.json ./
COPY gulpfile.js ./
COPY __BUILD_NUMBER ./

How can I copy all of these files by using just one layer instead?

I also tried this:

COPY [
    "__BUILD_NUMBER ./",
    "README.md ./",
    "gulpfile ./",
    "another_file ./",
]

Answer 1

Try this command out:

COPY README.md package.json gulpfile.js __BUILD_NUMBER ./

or

COPY ["__BUILD_NUMBER", "README.md", "gulpfile", "another_file", "./"]

You can also make use of the wild card characters in your sourcefile.

Keep in mind that directories are a bit special, so when you write:

COPY dir1 dir2 ./

it actually works like this

COPY dir1/* dir2/* ./

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