fs-azureblob

Installation

The package can be installed via pip:

pip install git+https://github.com/Breakthrough-Energy/fs-azureblob

Or by cloning the repository and installing directly:

git clone https://github.com/Breakthrough-Energy/fs-azureblob
cd fs-azureblob
pip install .

Either approach will also install the core fs package if it's not already installed.

Usage

This library implements the pyfilesystem API for blob storage containers in a general purpose storage account. There are implementations for the original blob storage, which uses a flat namespace with virtual directories, and accounts with hierarchical namespace enabled, which adds native directory support as well as other features. The type of account must be specified when a filesystem is instantiated: use the azblob protocol, or BlobFS class for accounts with a flat namespace, or the azblobv2 protocol or the BlobFSV2 class for accounts with a hierarchical namespace.

Opener

Use fs.open_fs to open a filesystem with an azure blob FS URL, where protocol is either azblob or azblobv2:

import fs
my_fs = fs.open_fs("[protocol]://[account_name]:[account_key]@[container]")

Constructor

The BlobFS (or BlobFSV2) class can also be instantiated directly

from fs.azblob import BlobFS
my_fs = BlobFS(account_name, container, account_key)

using the following arguments:

• account_name: the name of the storage account
• container: the blob container
• account_key: optional, but required for write operations or depending on the storage account access policies

Resource Info

Users can call getinfo for the basic and details namespaces, however support for setinfo is limited, as these properties are enforced by azure (e.g. last modified time). There is a custom namespace called blob which can be used to set metadata on a blob, in the form of key value pairs which must be valid http headers.

Additionally, the v2 filesystem for hierarchical namespaces supports posix permissions, so the access namespaces is supported for getinfo calls, which includes this information.

See docs for more details.

Note

The following can be ignored if using an account with hierarchical namespace.

Since blob storage uses a flat namespace (directories don't really exist), we create a placeholder file to represent them, always named .fs_azblob. This is an empty blob which is created for new directories, removed when a directory is removed, and omitted from listdir results, so should be transparent to users. To use this package on a new blob storage container, nothing needs to be done. For usage on an existing container, one should create this structure using the azure portal, sdk, or preferred tool, to ensure this package will function as expected.

Additionally, this package is intended to operate on "block blobs". Other blob types include page blobs and append blobs. The package has not been tested on these types.

See also

• fs, the core PyFilesystem2 library