datalad create-sibling-ria

Synopsis

datalad create-sibling-ria [-h] -s NAME [-d DATASET] [--storage-name NAME] [--alias ALIAS]
    [--post-update-hook] [--shared
    {false|true|umask|group|all|world|everybody|0xxx}] [--group
    GROUP] [--storage-sibling MODE] [--existing MODE]
    [--new-store-ok] [--trust-level TRUST-LEVEL] [-r] [-R LEVELS]
    [--no-storage-sibling] [--push-url
    ria+<ssh|file>://<host>[/path]] [--version]
    ria+<ssh|file|https>://<host>[/path]

Description

Creates a sibling to a dataset in a RIA store

Communication with a dataset in a RIA store is implemented via two siblings. A regular Git remote (repository sibling) and a git-annex special remote for data transfer (storage sibling) – with the former having a publication dependency on the latter. By default, the name of the storage sibling is derived from the repository sibling’s name by appending “-storage”.

The store’s base path is expected to not exist, be an empty directory, or a valid RIA store.

RIA URL format

Interactions with new or existing RIA stores require RIA URLs to identify the store or specific datasets inside of it.

The general structure of a RIA URL pointing to a store takes the form ‘ria+[scheme]://<storelocation>’ (e.g., ria+ssh://[user@]hostname:/absolute/path/to/ria-store, or ria+file:///absolute/path/to/ria-store)

The general structure of a RIA URL pointing to a dataset in a store (for example for cloning) takes a similar form, but appends either the datasets UUID or a ~ symbol followed by the dataset’s alias name: ‘ria+[scheme]://<storelocation>#<dataset-UUID>’ or ‘ria+[scheme]://<storelocation>#~<aliasname>’. In addition, specific version identifiers can be appended to the URL with an additional @ symbol: ‘ria+[scheme]://<storelocation>#<dataset-UUID>@<dataset-version>’, where ‘dataset-version’ refers to a branch or tag.

RIA store layout

A RIA store is a directory tree with a dedicated subdirectory for each dataset in the store. The subdirectory name is constructed from the DataLad dataset ID, e.g. ‘124/68afe-59ec-11ea-93d7-f0d5bf7b5561’, where the first three characters of the ID are used for an intermediate subdirectory in order to mitigate files system limitations for stores containing a large number of datasets.

By default, a dataset in a RIA store consists of two components: A Git repository (for all dataset contents stored in Git) and a storage sibling (for dataset content stored in git-annex).

It is possible to selectively disable either component using storage-sibling 'off' or storage-sibling 'only', respectively. If neither component is disabled, a dataset’s subdirectory layout in a RIA store contains a standard bare Git repository and an ‘annex/’ subdirectory inside of it. The latter holds a Git-annex object store and comprises the storage sibling. Disabling the standard git-remote (‘storage-sibling=only’) will result in not having the bare git repository, disabling the storage sibling (‘storage-sibling=off’) will result in not having the ‘annex/’ subdirectory.

Optionally, there can be a further subdirectory ‘archives’ with (compressed) 7z archives of annex objects. The storage remote is able to pull annex objects from these archives, if it cannot find in the regular annex object store. This feature can be useful for storing large collections of rarely changing data on systems that limit the number of files that can be stored.

Each dataset directory also contains a ‘ria-layout-version’ file that identifies the data organization (as, for example, described above).

Lastly, there is a global ‘ria-layout-version’ file at the store’s base path that identifies where dataset subdirectories themselves are located. At present, this file must contain a single line stating the version (currently “1”). This line MUST end with a newline character.

It is possible to define an alias for an individual dataset in a store by placing a symlink to the dataset location into an ‘alias/’ directory in the root of the store. This enables dataset access via URLs of format: ‘ria+<protocol>://<storelocation>#~<aliasname>’.

Compared to standard git-annex object stores, the ‘annex/’ subdirectories used as storage siblings follow a different layout naming scheme (‘dirhashmixed’ instead of ‘dirhashlower’). This is mostly noted as a technical detail, but also serves to remind git-annex powerusers to refrain from running git-annex commands directly in-store as it can cause severe damage due to the layout difference. Interactions should be handled via the ORA special remote instead.

Error logging

To enable error logging at the remote end, append a pipe symbol and an “l” to the version number in ria-layout-version (like so ‘1|ln’).

Error logging will create files in an “error_log” directory whenever the git-annex special remote (storage sibling) raises an exception, storing the Python traceback of it. The logfiles are named according to the scheme ‘<dataset id>.<annex uuid of the remote>.log’ showing “who” ran into this issue with which dataset. Because logging can potentially leak personal data (like local file paths for example), it can be disabled client-side by setting the configuration variable “annex.ora-remote.<storage-sibling-name>.ignore-remote-config”.

Options

ria+<ssh|file|http(s)>://<host>[/path]

URL identifying the target RIA store and access protocol. If --push-url is given in addition, this is used for read access only. Otherwise it will be used for write access too and to create the repository sibling in the RIA store. Note, that HTTP(S) currently is valid for consumption only thus requiring to provide --push-url. Constraints: value must be a string or value must be NONE

-h, -\-help, -\-help-np

show this help message. –help-np forcefully disables the use of a pager for displaying the help message

-s NAME, -\-name NAME

Name of the sibling. With RECURSIVE, the same name will be used to label all the subdatasets’ siblings. Constraints: value must be a string or value must be NONE

-d DATASET, -\-dataset DATASET

specify the dataset to process. If no dataset is given, an attempt is made to identify the dataset based on the current working directory. Constraints: Value must be a Dataset or a valid identifier of a Dataset (e.g. a path) or value must be NONE

-\-storage-name NAME

Name of the storage sibling (git-annex special remote). Must not be identical to the sibling name. If not specified, defaults to the sibling name plus ‘-storage’ suffix. If only a storage sibling is created, this setting is ignored, and the primary sibling name is used. Constraints: value must be a string or value must be NONE

-\-alias ALIAS

Alias for the dataset in the RIA store. Add the necessary symlink so that this dataset can be cloned from the RIA store using the given ALIAS instead of its ID. With recursive=True, only the top dataset will be aliased. Constraints: value must be a string or value must be NONE

-\-post-update-hook

Enable Git’s default post-update-hook for the created sibling. This is useful when the sibling is made accessible via a “dumb server” that requires running ‘git update-server-info’ to let Git interact properly with it.

-\-shared {false|true|umask|group|all|world|everybody|0xxx}

If given, configures the permissions in the RIA store for multi-users access. Possible values for this option are identical to those of git init –shared and are described in its documentation. Constraints: value must be a string or value must be convertible to type bool or value must be NONE

-\-group GROUP

Filesystem group for the repository. Specifying the group is crucial when –shared=group. Constraints: value must be a string or value must be NONE

-\-storage-sibling MODE

By default, an ORA storage sibling and a Git repository sibling are created (on). Alternatively, creation of the storage sibling can be disabled (off), or a storage sibling created only and no Git sibling (only). In the latter mode, no Git installation is required on the target host. Constraints: value must be one of (‘only’,) or value must be convertible to type bool or value must be NONE [Default: True]

-\-existing MODE

Action to perform, if a (storage) sibling is already configured under the given name and/or a target already exists. In this case, a dataset can be skipped (‘skip’), an existing target repository be forcefully re-initialized, and the sibling (re-)configured (‘reconfigure’), or the command be instructed to fail (‘error’). Constraints: value must be one of (‘skip’, ‘error’, ‘reconfigure’) [Default: ‘error’]

-\-new-store-ok

When set, a new store will be created, if necessary. Otherwise, a sibling will only be created if the url points to an existing RIA store.

-\-trust-level TRUST-LEVEL

specify a trust level for the storage sibling. If not specified, the default git-annex trust level is used. ‘trust’ should be used with care (see the git- annex-trust man page). Constraints: value must be one of (‘trust’, ‘semitrust’, ‘untrust’)

-r, -\-recursive

if set, recurse into potential subdatasets.

-R LEVELS, -\-recursion-limit LEVELS

limit recursion into subdatasets to the given number of levels. Constraints: value must be convertible to type ‘int’ or value must be NONE

-\-no-storage-sibling

This option is deprecated. Use ‘–storage-sibling off’ instead.

-\-push-url ria+<ssh|file>://<host>[/path]

URL identifying the target RIA store and access protocol for write access to the storage sibling. If given this will also be used for creation of the repository sibling in the RIA store. Constraints: value must be a string or value must be NONE

-\-version

show the module and its version which provides the command

Authors

datalad is developed by The DataLad Team and Contributors <team@datalad.org>.