ADD command incorrect for tar.gz files about docker-maven-plugin

[davidxia]

@aburnett So the Dockerfile command should be ADD /opt/apps/spar-api.tar.gz /opt/apps/?

[chris-snider]

Hi,

According to the docker docs, an ADD is supposed to copy and unpack if in a recognized format. If you want to have a copy of the tar.gz in the resulting image, a copy command should be used.

REF: https://docs.docker.com/reference/builder/#add
• If is a local tar archive in a recognized compression format (identity, gzip, bzip2 or xz) then it is unpacked as a directory. Resources from remote URLs are not decompressed. When a directory is copied or unpacked, it has the same behavior as tar -x: the result is the union of:

1. Whatever existed at the destination path and
2. The contents of the source tree, with conflicts resolved in favor of “2.” on a file-by-file basis.

REF: http://stackoverflow.com/questions/24958140/docker-copy-vs-add

You should check the ADDhttp://docs.docker.com/reference/builder/#add and COPYhttp://docs.docker.com/reference/builder/#copy documentations for an exhaustive description of their behaviours, but in a nutshell the major difference is that ADD can do more than COPY:

• ADD allows to be an URL
• If the parameter of ADD is an archive in a recognised compression format, it will be unpacked

Chris Snider
Senior Software Engineer
Intelligent Software Solutions, Inc.
[Description: Description: Description: cid:[email protected]]

From: David Xia [mailto:[email protected]]
Sent: Wednesday, August 12, 2015 7:48 AM
To: spotify/docker-maven-plugin [email protected]
Subject: Re: [docker-maven-plugin] ADD command incorrect for tar.gz files (#123)

@aburnetthttps://github.com/aburnett So the Dockerfile command should be ADD /opt/apps/spar-api.tar.gz /opt/apps/?

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Reply to this email directly or view it on GitHubhttps://github.com//issues/123#issuecomment-130312306.

[davidxia]

Yea I saw that. I think we all agree that ADD unpacks tar archives. The question is whether this plugin should be smart about tar files and instead of naively writing ADD /opt/apps/spar-api.tar.gz /opt/apps/spar-api.tar.gz write ADD /opt/apps/spar-api.tar.gz /opt/apps/ instead so that the contents of the archive aren't nested in a misleadingly named parent folder.

[aburnett]

@chris-snider that's correct about copy/add. I'm going for copy+unpack so ADD is correct.

@davidxia ya, that's what I think the command should be. Perhaps the easiest solution is to just pass targetPath verbatim as the last argument to ADD. Then the behavior would match the docs and you wouldn't have to get fancy in the plugin.