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.
Notes
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|l\n).
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.
--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