rocfl

rocfl is a command line utility for interacting with OCFL repositories on the local filesystem or in S3. Its goal is to provide a logical view of OCFL objects and make them easy to interact with in a unix-like way.

Extension Support

rocfl supports the following extensions:

• 0001-digest-algorithms
• 0002-flat-direct-storage-layout
• 0003-hash-and-id-n-tuple-storage-layout
• 0004-hashed-n-tuple-storage-layout
• 0005-mutable-head: Only read is supported; not write.
• 0006-flat-omit-prefix-storage-layout

Additionally, it uses the following extensions for write support that have not been specified:

• rocfl-staging: By default, new object versions are staged in this extension's directory the contents of which are OCFL repository like.
• rocfl-locks: This extension contains object file locks that provide limited concurrent modification protection.

Install

The releases page has pre-built binaries that should work on most common OSes and architectures. You do not need to install Rust to use them.

1. Download and unzip the appropriate binary
2. On Linux or Mac, execute chmod +x rocfl to fix the permissions
3. Execute ./rocfl --help to verify it works

Local Build

Alternatively, you can build rocfl from source as follows:

1. Install Rust, and make sure cargo is on your PATH
2. Execute: cargo install rocfl
3. Verify the install: rocfl --help

If you want to build a binary that does not include the S3 integration, which adds a large number of dependencies, then you can do so by running: cargo install rocfl --no-default-features.

Configuration

rocfl supports optional configuration that makes it less verbose to use. rocfl expects to find its configuration file in the following, OS dependent location:

• Linux: $HOME/.config/rocfl/config.toml
• Mac: $HOME/Library/Application Support/org.rocfl.rocfl/config.toml
• Windows: {FOLDERID_RoamingAppData}/rocfl/rocfl/config/config.toml

You can easily edit the configuration by executing rocfl config, which will create/open the config file for editing.

The config file may contain any number of sections structured as follows:

[repo-name]
# The name to attribute new OCFL versions to
author_name = "My Name"
# The URI address to associate with the above name
author_address = "mailto:name@example.com"
# The absolute path to the OCFL storage root
root = "/path/to/storage/root"
# The absolute path to the OCFL staging root
staging_root = "/path/to/staging/root"

# The next properties only apply when using S3
# The AWS region your bucket is in
region = "aws-region"
# The URL to the S3 endpoint. This is only needed if you are using a non-standard region
endpoint = "https://s3-endpoint"
# The S3 bucket the OCFL repository is in
bucket = "s3-bucket"

repo-name is the arbitrary name assigned to the configuration. This is the value that you pass rocfl when invoking the --name option.

A special [global] section may be used to provide default values across all configurations. This is primarily useful for defining author_name and author_address.

All of these properties correspond to values that can be specified in arguments to rocfl. rocfl resolves the configuration by first loading the global config, then overlays the repository specific config, and finally applies any values specified directly as command line arguments.

Refer to the command line argument documentation for more information on the configuration properties.

Usage

The following is an overview of the features that rocfl supports. For a detailed description of all of the options available, consult the builtin help by executing rocfl --help or rocfl <COMMAND> --help.

Read Commands

List

The ls command can be used to either list the objects in a repository or list the files in an OCFL object.

rocfl must scan the repository to locate objects. This can be slow when operating on large repositories. The scan can be avoided when listing an object's contents if the repository uses a supported storage layout extension that is defined in the repository's ocfl_layout.json

When listing files, only files in the most recent version are returned. Previous versions can be queried with the -v option.

Examples

Listing Objects

The following command lists all of the object IDs in a repository that's rooted in the current working directory:

rocfl ls

This lists the same objects but with additional details, current version and updated date:

rocfl ls -l

Adding the -p flag additionally provides the path from the storage root to the object:

rocfl ls -lp

A subset of objects can be listed by providing a glob pattern to match on:

rocfl ls -lo '*object*'

Listing Object Contents

The contents of an object's current state are displayed by invoking ls on a specific object ID:

rocfl ls uri:object-1

With the -l flag, additional details are displayed. In this case, the version and date indicate when the individual file was last updated:

rocfl ls -l uri:object-1

The -p flag can also be used here to display the paths to the physical files on disk relative the storage root:

rocfl ls -p uri:object-1

The contents of previous versions are displayed by using the -v option. The following command displays the files that were in the first version of the object:

rocfl ls -v1 uri:object-1

An object's contents can be filtered by specifying a glob pattern to match on:

rocfl ls uri:object-1 '*.txt'

The output is sorted by name by default, but can also be sorted version or updated date:

rocfl ls -l -s version uri:object-1

Paths within in an object can be interpreted as containing logical directories by using the -D flag. For example, the following will list the logical files and logical directories that are direct children of the logical directory sub/dir:

rocfl ls -D uri:object-1 sub/dir

Log

The log command displays the version metadata for all versions of an object. It can also be executed on a file within an object, in which case only versions that affected the specified file are displayed.

Examples

Show all of the versions of an object in ascending order:

rocfl log uri:object-1

Only display the five most recent versions:

rocfl log -rn5 uri:object-1

Show all of the versions, but formatted so each version is on a single line:

rocfl log -c uri:object-1

Show all of the versions that affected a specific file:

rocfl log uri:object-1 file1.txt

Show

The show command displays everything that changed in an object within a specific version. If no version is specified, the most recent changes are shown.

Examples

Show the changes in the most recent version:

rocfl show uri:object-1

Show the changes in the first version:

rocfl show uri:object-1 v1

Don't show the version metadata; only show the files that changed:

rocfl show -m uri:object-1

Diff

The diff command displays the files that changed between two specific versions.

Example

Show the changes between the second and fourth versions:

rocfl diff v2 v4

Cat

The cat command writes the contents of a file to stdout.

Examples

Display the contents of the head version of a file:

rocfl cat uri:object-1 file1.txt

Display the contents of a file from a specific version of the object:

rocfl cat -v1 uri:object-1 file1.txt

Status

The status command shows objects that have staged changes pending commit, as well as what an object's pending changes are.

Examples

List all of the objects with staged changes:

rocfl status

List all of the file level changes to an object:

rocfl status uri:object-1

Staged changes can also be examined using the more featureful ls, show, and cat commands by adding the -S flag.

Write Commands

rocfl supports updating OCFL objects by staging changes to objects in a local staging repository. For filesystem based repositories, the staging repository is located within the storage root's extensions directory, and for S3 it's in the user's home application data.

The intended workflow is to accumulate a collection of updates to an object, and then commit all of the changes to the object a single new OCFL version.

Init

The init command creates new OCFL repositories.

Examples

Create a new repository using the default layout, 0004-hashed-n-tuple-storage-layout:

rocfl -r /var/tmp/ocfl-repo-1 init

The default layout configuration can be changed by passing a config file that contains the desired configuration:

rocfl -r /var/tmp/ocfl-repo-2 init -l 0003-hash-and-id-n-tuple-storage-layout -c
my-config.json

New

The new command stages new OCFL objects. New objects will not exist in the main repository until they have been committed. When invoked with no options, the object is created using all of the OCFL spec recommend values.

Examples

Create a new object with non-standard settings:

rocfl new uri:object-1 -d sha256 -c data -z 6

Copy

The cp command copies files from the local filesystem into a staged object, or copies logical paths within an object to a new location within the same object. This command attempts to mimic the behavior of GNU cp as closely as possible.

Examples

Copy a directory into the object's root:

rocfl cp -r uri:object-1 /path/to/src -- /

Copy several files into a logical directory within the object:

rocfl cp uri:object-1 /path/to/files/* -- sub/dir

Copy several existing files internally to a new location:

rocfl cp -i uri:object-1 'internal/*.txt' -- new-location

Copy an entire logical directory from an old version to a new location in the staged version:

rocfl cp -ir -v2 uri:object-1 src/dir -- dst/dir

Move

The mv command moves files from the local filesystem into a staged object, or moves logical paths within an object to a new location within the same object. This command attempts to mimic the behavior of GNU mv as closely as possible.

Examples

Move a directory into the object's root:

rocfl mv uri:object-1 /path/to/src -- /

Move several files into a logical directory within the object:

rocfl mv uri:object-1 /path/to/files/* -- sub/dir

Move an existing file internally to a new location:

rocfl mv -i uri:object-1 internal/file.txt -- new/location.txt

Remove

The rm command removes files from an object. If the removed files were new to the staged version, then they are permanently removed and will not appear anywhere in the object. Otherwise, references to the files are removed from the staged version, but the files still exist in prior versions.

Examples

Recursively remove a logical directory:

rocfl rm -r uri:object-1 path/to/dir

Remove several individual files:

rocfl rm uri:object-1 path/to/file1.txt path/to/file2.txt

Or with a glob:

rocfl rm uri:object-1 'path/to/*.txt'

Reset

The reset command unstages changes made to an object. Additions are removed and files that were deleted or modified are reverted to their previous state.

Examples

Reset a file to its previous state:

rocfl reset uri:object-1 file.txt

Reset an entire object to its previous state, removing all staged changes:

rocfl reset uri:object-1

Commit

The commit command moves an object's staged changes into the OCFL object as a new version.

Examples

Commit changes to an object:

rocfl commit uri:object-1 -n "My Name" -a "mailto:me@example.com" -m "commit
message"

This can be simplified if you define your name and address in rocfl configuration. In which case, you can simply execute:

rocfl commit uri:object-1 -m "commit message"

And your name and address will be automatically added to the version metadata.

In order to commit an object to a repository without a defined storage layout, the location to store the object with the repository must be manually specified as follows:

rocfl commit uri:object-1 -m "commit message" -r relative/path/to/object/root

Purge

The purge command permanently removes an object from the main OCFL repository. This is not an operation that stages changes. However, it will ask for confirmation before deleting an object.

S3

S3 Configuration

To connect to an OCFL repository in S3, you first need to create an IAM user with access to the S3 bucket, and then setup a local ~/.aws/credentials file or environment variables as described here. Then, when you invoke rocfl you must specify the bucket the repository is in as well as the bucket region. For example:

rocfl -R us-east-2 -b example-ocfl-repo ls

You can specify a sub directory, or prefix, that the repository is rooted in within the bucket like this:

rocfl -R us-east-2 -b example-ocfl-repo -r ocfl-root ls

Changes to objects are staged locally and are only pushed to S3 when the staged version is committed. By default, changes are staged in the following location:

• Linux: $HOME/.local/share/rocfl/s3/staging/<sha256:BUCKET/ROOT>
• Mac: {FOLDERID_RoamingAppData}/org.rocfl.rocfl/data/s3/staging/<sha256:BUCKET/ROOT>
• Windows: $HOME/Library/Application Support/rocfl/rocfl/s3/staging/<sha256:BUCKET/ROOT>

This location can be changed by setting the --staging-root option.

All of these properties can define defined in rocfl's config file, and activated by invoking rocfl using the configuration NAME as follows:

rocfl -n NAME ls

Important S3 Considerations

While rocfl supports all of the same operations on S3 as it does the local filesystem, this does come with a couple of caveats:

1. Scanning for objects in S3 is very slow, and using a defined storage layout extension is key to improving performance.
2. rocfl does not provide any strong concurrency guarantees when modifying objects in S3. A file lock is used to guard changes in the staging repository, but there is an unchecked race condition if multiple processes attempt to commit changes to the same object from different staging locations.

Roadmap

The following features are planned:

1. Export objects to a location outside the repository
2. Index objects when the storage layout is unknown
3. Validate objects
4. Validate repositories
5. Unsafe mutating operations such as squash, revert, and rewrite that can be used to change an object's history