COPY with docker but with exclusion

Question

In a Dockerfile, I have

COPY . .

I want to exclude an entire directory, in my case, node_modules directory.

Something like this:

   COPY [all but **/node_modules/**] .

Is this possible with Docker?

Answer 1

Create file .dockerignore in your docker build context directory (so in this case, most likely a directory that is a parent to node_modules) with one line in it:

**/node_modules

although you probably just want:

node_modules

Info about dockerignore: https://docs.docker.com/engine/reference/builder/#dockerignore-file

Answer 2

For those who can't use a .dockerignore file (e.g. if you need the file in one COPY but not another):

Yes, but you need multiple COPY instructions. Specifically, you need a COPY for each letter in the filename you wish to exclude.

COPY [^n]*    # All files that don't start with 'n'
COPY n[^o]*   # All files that start with 'n', but not 'no'
COPY no[^d]*  # All files that start with 'no', but not 'nod'

Continuing until you have the full file name, or just the prefix you're reasonably sure won't have any other files.

Answer 3

Adding .dockerignore works for me. One additional point Those who are trying this solution on Windows , windows will not let you create .dockerignore file (as it doesn't by default allows creating file starting with .)

To create such file starting with . on Windows, include an ending dot also, like : .dockerignore. and hit enter ( provided you have enabled view extension options from folder options )

Answer 4

FOR A ONE LINER SOLUTION, type the following in Command prompt or Terminal at project root.

echo node_modules >> .dockerignore

This command appends "node_modules" in the .dockerignore file. If the .dockerignore does not exist already, it will create a new one. Replace node_modules with the folder you want to exclude.

Warning: If you are new to Docker ecosystem and/or you already have the .dockerignore file in your project, please take a backup before proceeding.

BONUS: (as pointed out by Joey Baruch)

(To CREATE/OVERWRITE the .dockerignore file via PowerShell, which can be handled by Docker):
>> echo node_modules | Out-File -Encoding UTF8 .dockerignore

Answer 5

Excluding node_modules from current directory

node_modules

Excluding node_modules in any immediate subdirectories

*/node_modules

Here is the official docs

Answer 6

For those using gcloud build:

gcloud build ignores .dockerignore and looks instead for .gcloudignore

Use:

cp .dockerignore .gcloudignore

Source