The dump plugin

doc
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The dump plugin makes all files from a specified source available to a part. By default, it’s equivalent to running the following command in a source’s directory:

cp --archive --link --no-dereference . "${CRAFT_PART_INSTALL}"

The source and other source-* properties are key to this plugin. They specify the location from where to retrieve the files, or if the source is a git repository, which branch, tag, or commit to clone.

For an artificial example:

parts:
  my-part:
    source: local-source/
    plugin: dump
    organize:
      '*.png' : images/
      launch.wrapper: usr/bin/launcher
    prime:
      - -README*
  remote-part:
    plugin: dump
    source: https://remote-resource.org/cool-package.deb
    source-type: deb

Combining the dump plugin with the part keys allows extending the behavior to create new files, modify existing files, or filter files for the final package. For example, you could use override-build to convert file formats.

The plugin can also be used with the organize key to reorganize the files in the final payload. For example, you could use it to keep libraries but exclude binaries and headers from SDKs.

If you aren’t using the source files directly in the package, but want to run some custom commands to generate them, then you should instead use the nil plugin so no files are copied unnecessarily.

Further reading

For more examples of the dump plugin, search GitHub for snaps that use it.

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Since the target destination is never mentioned in these dump/organize examples, is it true that the target is the /root/prime virtual machine directory during the build process (which ends up as the root of the snap)?

Thus the dump command above copies the files from local-source/ into prime and the organize moves them into subdirs of prime, so that for example:

  • local-source/*.png ends up in /prime and then they all get moved into /prime/images/
  • local-source/launch.wrapper ends up in /prime and then gets moved into /prime/usr/bin/launcher/launch.wrapper
3

It is true that the target will end up be placing at the root of the snap file hierachy, what is unnecessarily true that it will always match the /root/prime virtual machine directory since that’s a Snapcraft internal implementation details.

Also the plugins only affect what will be contained in the SNAPCRAFT_PART_INSTALL directory in the part’s build step, whether the file will end in SNAPCRAFT_PRIME directory will also be determined by the stage and prime step.

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I don’t understand this completely.

The presented options are:

  • fileset: filesets appear to be a way to group files and operate on the group at once.
  • stage: no clue what this does. “A list of files from to stage.” This tells me very little.
  • snap: I can’t find anything called snap in the common keywords link.
  • organize: I think I understand from the example that organize will rename files.

I am specifically here looking how to insert only a specific file into the snap. I just want foo/bar.sh included in my snap. I have learned from trial and error that source: ./foo will include ALL files from foo in the snap, dumped into the base directory of the snap. It would be nice to have this called out.

“This plugin just dumps the content from a specified source(directory, url, git link, etc) into the base directory of the resulting snap.”?

I then started to dig through the example and look things up. Looking up prime doesn’t result in any information about what it does. It just says “A list of files from to prime.” and prime links to a page that says “Migrate this part’s staged material into the final priming area”. What is my staged material? Where is the final priming area? Why do I need to know that? This doesn’t make sense unless you have a lot of internal knowledge about how snaps work.

I’m just trying to make a zip of my application here. I don’t need to know how zip works or what temporary directories are used. I’ve now clicked on 3 links going back and forth to try and decrypt how to say “copy random filename to snap”. It is very easy at this point for a potential user to be confused and give up at this point.

Could we add some more examples and document the one that is there? I assume ‘*.png’: images/ will move all png images into a img directory, but leave all jpg files for example. That stuff seems intuitive and maybe include this single file is as well, but unless it is shown I don’t see how a user can find it easily.

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5

I’m struggling to understand where the files go with this plugin. Where do they go? How do I change the destiny? Can I chose if they go to $SNAP or $SNAP_COMMON?

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It goes to the part’s install directory(/root/parts/part_name/install), then to /stage, then to /prime, then to the snap’s root directory($SNAP) if not moved or pruned by the organize, stage, or prime keywords.

Can I chose if they go to $SNAP or $SNAP_COMMON?

You can organize the files to your preferred paths under $SNAP but not $SNAP_COMMON

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7

How to copy only certain specified files and not the whole source?

Also, Would be nice to have the documentation updated of this plugin with the definition of all the keywords used with their meaningful use case.

Thanks :slight_smile:

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This document says

This plugin uses also common plugin keywords.

But if you check the link there’s no such information.

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Hi

Does setting source-type to deb also stage its dependencies?

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Apologies, it should be prime

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This example seems confusing in that the second part, “remote-part”, doesn’t seem to be contributing any information about the dump plugin as it doesn’t even specify a plugin. I would delete that second part entirely for clarity.

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Indeed, it doesn’t even work as stated. Needs plugin: dump added.

(which like a swift ninja in the night, I just added)

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@degville

Hello, I think this topic is also not authored by me, it seems that the initial edit history is lost somehow…

14

Incorporated some wording from @mr_cal’s latest documentation.

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