miarec-s3fs 2024.1.1

Amazon S3 filesystem for PyFilesystem2

miarec_s3fs

MiaRec S3FS is a PyFilesystem interface to Amazon S3 cloud storage.

As a PyFilesystem concrete class, S3FS allows you to work with S3 in the same way as any other supported filesystem.

This a fork of the fs-s3fs project, written by Will McGugan (email [e-mail]).

The code was modified by MiaRec team to fullfill out needs.

Notable differences between miarec_s3fs and fs-s3fs

1. Required Python 3.6+. A support of Python 2.7 is removed.

2. Opener is not implemented. Use explicit constructor instead.

3. Unit tests are run with moto

Installing

You can install S3FS from pip as follows:

pip install miarec_s3fs

This will install the most recent stable version.

Alternatively, if you want the cutting edge code, you can check out the GitHub repos at https://github.com/miarec/miarec_s3fs

Opening a S3FS

Open an S3FS by explicitly using the constructor:

from fs_s3fs import S3FS
s3fs = S3FS('mybucket')

Limitations

Amazon S3 isn't strictly speaking a filesystem, in that it contains files, but doesn't offer true directories. S3FS follows the convention of simulating directories by creating an object that ends in a forward slash. For instance, if you create a file called "foo/bar", S3FS will create an S3 object for the file called "foo/bar" and an empty object called "foo/" which stores that fact that the "foo" directory exists.

If you create all your files and directories with S3FS, then you can forget about how things are stored under the hood. Everything will work as you expect. You may run in to problems if your data has been uploaded without the use of S3FS. For instance, if you create a "foo/bar" object without a "foo/" object. If this occurs, then S3FS may give errors about directories not existing, where you would expect them to be. The solution is to create an empty object for all directories and subdirectories. Fortunately most tools will do this for you, and it is probably only required of you upload your files manually.

Authentication

If you don't supply any credentials, then S3FS will use the access key and secret key configured on your system.

Here's how you specify credentials with the constructor:

s3fs = S3FS(
    'mybucket'
    aws_access_key_id=<access key>,
    aws_secret_access_key=<secret key>
)

Note: Amazon recommends against specifying credentials explicitly like this in production.

Downloading Files

To download files from an S3 bucket, open a file on the S3 filesystem for reading, then write the data to a file on the local filesystem. Here's an example that copies a file example.mov from S3 to your HD:

from fs.tools import copy_file_data
with s3fs.open('example.mov', 'rb') as remote_file:
    with open('example.mov', 'wb') as local_file:
        copy_file_data(remote_file, local_file)

Although it is preferable to use the higher-level functionality in the fs.copy module. Here's an example:

from fs.copy import copy_file
copy_file(s3fs, 'example.mov', './', 'example.mov')

Uploading Files

You can upload files in the same way. Simply copy a file from a source filesystem to the S3 filesystem. See Moving and Copying for more information.

ExtraArgs

S3 objects have additional properties, beyond a traditional filesystem. These options can be set using the upload_args and download_args properties. which are handed to upload and download methods, as appropriate, for the lifetime of the filesystem instance.

For example, to set the cache-control header of all objects uploaded to a bucket:

import fs, fs.mirror
s3fs = S3FS('example', upload_args={"CacheControl": "max-age=2592000", "ACL": "public-read"})
fs.mirror.mirror('/path/to/mirror', s3fs)

see the Boto3 docs for more information.

S3 Info

You can retrieve S3 info via the s3 namespace. Here's an example:

>>> info = s.getinfo('foo', namespaces=['s3'])
>>> info.raw['s3']
{'metadata': {}, 'delete_marker': None, 'version_id': None, 'parts_count': None, 'accept_ranges': 'bytes', 'last_modified': 1501935315, 'content_length': 3, 'content_encoding': None, 'request_charged': None, 'replication_status': None, 'server_side_encryption': None, 'expires': None, 'restore': None, 'content_type': 'binary/octet-stream', 'sse_customer_key_md5': None, 'content_disposition': None, 'storage_class': None, 'expiration': None, 'missing_meta': None, 'content_language': None, 'ssekms_key_id': None, 'sse_customer_algorithm': None, 'e_tag': '"37b51d194a7513e45b56f6524f2d51f2"', 'website_redirect_location': None, 'cache_control': None}

S3 URLs

You can use the geturl method to generate an externally accessible URL from an S3 object. Here's an example:

>>> s3fs.geturl('foo')
'https://fsexample.s3.amazonaws.com//foo?AWSAccessKeyId=AKIAIEZZDQU72WQP3JUA&Expires=1501939084&Signature=4rfDuqVgmvILjtTeYOJvyIXRMvs%3D'

Testing

Automated unit tests are run on GitHub Actions

To run the tests locally, do the following.

Install Docker on local machine.

Create activate python virtual environment:

python -m vevn venv
source venv\bin\activate

Install the project and test dependencies:

pip install -e ".[test]"

Run tests:

pytest

Documentation

• PyFilesystem Wiki
• PyFilesystem Reference