DL3010 : Use ADD for extracting archives into an image

Description

ADD automatically extracts local tar archives when the destination is a directory. Using COPY misses this feature.

Goals

• Leverage Docker's built-in archive extraction.
• Simplify Dockerfiles by using ADD for local archives.

Specification

1. Inspect each COPY instruction.
2. Skip instructions that include a --from= flag.
3. Collect the source and destination arguments.
4. If the destination ends with /, check each source path.
5. If any source has an archive extension (.tar, .tar.gz, .tgz, .tar.bz2, .tbz, .tar.xz, .txz), emit DL3010 at the instruction line suggesting ADD.

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