Azure Blob Storage

The Azure Blob Storage integration backs up and restores Azure Blob Storage containers, and can host a Kloset store in a container. A backup captures the container contents, including blobs, metadata and prefix hierarchies, and stores them in a Kloset store with encryption and deduplication.

The integration includes three connectors:

Requirements

• An Azure Storage account, or a local emulator such as Azurite.
• Credentials for that account. See Authentication.

Installation

The Azure Blob Storage package can be installed using pre-built binaries or compiled from source.

$ plakar pkg add azblob

$ plakar pkg show

$ plakar pkg build azblob

$ plakar pkg add -allow-unsigned ./azblob_v1.0.0_darwin_arm64.ptar

$ plakar pkg show

To list, upgrade, or remove the package, see managing packages guide.

Authentication

Every connector must be given credentials in one of the following forms:

• connection_string. This is the recommended form. It takes precedence over account_name and account_key.
• account_name and account_key.
• no_auth=true with a valid endpoint.

Configuration

All three connectors use the azblob:// protocol. The source connector retrieves blobs from a container through the Azure Blob API. The destination connector writes them back to a container. The store connector keeps all Kloset store data, including snapshots, chunks and metadata, as blobs in a container.

Backup flow

flowchart LR

subgraph Source["Azure Blob Container"]
  FS["Blobs"]
end

subgraph Plakar["Plakar"]
  Connector["Retrieve blobs via
Azure Blob API"]
  Transform["Encrypt & deduplicate"]
  Connector --> Transform
end

Source --> Connector

Store["Kloset Store"]
Transform --> Store

Restore flow

flowchart LR

Store["Kloset Store"]

subgraph Plakar["Plakar"]
  Transform["Decrypt & reconstruct"]
  Connector["Restore via
Azure Blob API"]
  Transform --> Connector
end

Store --> Transform

subgraph Destination["Azure Blob Container"]
  FS["Blobs"]
end

Connector --> Destination

Store flow

flowchart LR

subgraph Sources["Any Source"]
  FS["Data"]
end

subgraph Plakar["Plakar"]
  Transform["Encrypt & deduplicate"]
  Connector["Store via
Azure Blob API"]
  Transform --> Connector
end

Sources --> Transform

subgraph Storage["Azure Blob Container"]
  Store["Kloset Store"]
end

Connector --> Store

Shared configuration

The following options apply to the source, destination and store connectors.

Example

Back up a container:

$ plakar source add my-az-container \
  azblob://container_name \
  connection_string=<YOUR_CONN_STRING>

$ plakar at /var/backups backup "@my-az-container"

To back up a specific prefix within a container:

$ plakar at /var/backups backup "@my-az-container:path"

Restore a snapshot to a container:

$ plakar destination add my-az-restore \
  azblob://container_name \
  connection_string=<YOUR_CONN_STRING>

$ plakar at /var/backups restore -to "@my-az-restore"

Host a Kloset store in a container, initialize it and run a backup:

$ plakar store add my-az-store \
  azblob://container_name \
  connection_string=<YOUR_CONN_STRING>

$ plakar at "@my-az-store" create
$ plakar at "@my-az-store" backup /var/www

Limitations and scope

Azure Blob Storage uses containers instead of buckets. Blob storage is flat, and directory structures are simulated using prefixes. Empty directories are not preserved unless they contain blobs.

When using Azurite, provide either a connection string or account_name=devstoreaccount1 with a local endpoint.

See also

• Creating a Kloset Store
• Managing packages