Ensure that COPY is used instead of ADD in Dockerfiles

MediumLevel 1Manual reviewdocker

Description

You should use the COPY instruction instead of the ADD instruction in the Dockerfile. The COPY instruction simply copies files from the local host machine to the container file system. The ADD instruction could potentially retrieve files from remote URLs and perform operations such as unpacking them. Reported as a manual review item: the audit needs a site-specific judgement.

How it is checked

Audit method: Manual review

This recommendation cannot be checked automatically. A scan lists it with these instructions when you pass --include-manual.

Run the command below to get the list of images: docker images Run the command below against each image in the list above and look for any ADD instructions: docker history <IMAGE ID> Alternatively, if you have access to the Dockerfile for the image, you should verify that there are no ADD instructions.

How it is fixed

Fix method: Guidance or infrastructure patch

You should use COPY rather than ADD instructions in Dockerfiles.

Properties

Operating systems: Any
Tags: dockermanual
Reference: CIS Docker Benchmark v1.9.0 - 4.8 Ensure that COPY is used instead of ADD in Dockerfiles