KBI0025: Saving changes in datasets owned by other users#


Adina Wagner <adina.wagner@t-online.de>




sharedRepository, git config, multi-user


datalad_0.19.0, git_2.39.2

It is generally recommended to not share one and the same dataset or Git repository (i.e., the same directory on the file system) when collaborating with others. In the typical workflow for collaboration, each user has their own clone of the respective dataset instead. One of several reasons why sharing the same dataset is not ideal is that Git lets the operating system decide which Unix file permissions are applied, and typical umask configurations give write permissions only to the file owner, which in turn creates permission errors when a user other than the dataset owner saves a modification.

But if a dataset needs to be shared among several users, the following Git configuration can help:


The Git configuration code.sharedRepository can, when set to group (or true), make a repository or dataset shared between several users in the same Unix user group. This allows more users than just the dataset owner to save modifications. Other values (such as all, world, or everybody) make this possible for an even wider range of users, and the configuration can even take octal numbers that define a precise umask. To use them wisely, its good to have an understanding of file permissions. The NIH has an excellent overview.

Here is an example configuration in a new dataset:

$ datalad create my-shared-dataset
  create(ok): /tmp/my-shared-dataset (dataset)
$ cd my-shared-dataset
$ git config core.sharedRepository true

Afterwards, users on the same system can commit or save changes into the dataset as long as they are members of the same group. This is identical to creating the datasets as shared repositories (datalad create myds --shared=group, but does not require re-creating or re-initializing them.