buildkit/CopyIgnoredFile

Attempting to Copy file that is excluded by .dockerignore.

Property	Value
Severity	Warning
Category	Correctness
Default	Enabled

Description

When you use the ADD or COPY instructions in a Dockerfile, you should ensure that the files to be copied into the image do not match a pattern present in .dockerignore. Files which match the patterns in a .dockerignore file are not present in the context of the image when it is built. Trying to copy or add a file which is missing from the context will result in a build error.

Build context requirement

This rule needs build context information. In direct Dockerfile mode, pass a local context directory:

tally lint --context . Dockerfile

When linting a Bake or Compose entrypoint, tally uses the local context declared by the selected target or service:

tally lint docker-bake.hcl --target api
tally lint compose.yaml --service api

Remote, tar, git, and empty contexts are valid build declarations, but tally does not fetch or unpack them during linting. For those contexts, this rule only reports problems that can be determined without reading context files.

Examples

Given a .dockerignore containing */tmp/*: Bad:

FROM scratch
COPY ./tmp/helloworld.txt /helloworld.txt

Good:

FROM scratch
COPY ./forever/helloworld.txt /helloworld.txt

Reference