Azure Driver

The Azure driver stores objects in Azure Blob Storage. It implements the core driver.Driver interface plus MultipartDriver, PresignDriver, and RangeDriver capability interfaces.

Installation01

The Azure driver has its own Go module to isolate the Azure SDK dependency:

go get github.com/xraph/trove/drivers/azuredriver

Usage02

import (
    "context"
    "github.com/xraph/trove"
    "github.com/xraph/trove/drivers/azuredriver"
)

ctx := context.Background()

// Create and open the driver.
drv := azuredriver.New()
err := drv.Open(ctx, "azure://myaccount/mycontainer?key=mykey123")
if err != nil {
    log.Fatal(err)
}

// Use with Trove.
t, err := trove.Open(drv)

Connection String

drv := azuredriver.New()
err := drv.Open(ctx, "azure://myaccount/mycontainer?connection_string=DefaultEndpointsProtocol=https;AccountName=...")

Custom Endpoint (Azurite)

drv := azuredriver.New()
err := drv.Open(ctx, "azure://devstoreaccount1/testcontainer?endpoint=http://127.0.0.1:10000/devstoreaccount1")

DSN Format03

azure://ACCOUNT_NAME/CONTAINER?key=ACCESS_KEY
azure://ACCOUNT_NAME/CONTAINER?connection_string=CONN_STRING
azure://ACCOUNT_NAME/CONTAINER?endpoint=http://127.0.0.1:10000/ACCOUNT_NAME

Component	Description
`ACCOUNT_NAME`	Azure storage account name
`CONTAINER`	Default container name
`key`	Storage account access key
`connection_string`	Full Azure connection string (takes priority over other auth methods)
`endpoint`	Override endpoint URL (for Azurite emulator)

Capabilities04

The Azure driver implements these capability interfaces:

MultipartDriver

Upload large objects using Azure block blob staging:

if mp, ok := t.Driver().(driver.MultipartDriver); ok {
    uploadID, _ := mp.InitiateMultipart(ctx, "container", "large-file.zip",
        driver.WithContentType("application/zip"),
    )

    part1, _ := mp.UploadPart(ctx, "container", "large-file.zip", uploadID, 1, chunk1Reader)
    part2, _ := mp.UploadPart(ctx, "container", "large-file.zip", uploadID, 2, chunk2Reader)

    info, _ := mp.CompleteMultipart(ctx, "container", "large-file.zip", uploadID,
        []driver.PartInfo{*part1, *part2},
    )
}

Azure multipart uploads work by staging blocks with StageBlock() and committing them with CommitBlockList().

PresignDriver

Generate SAS URLs for direct client access:

if ps, ok := t.Driver().(driver.PresignDriver); ok {
    downloadURL, _ := ps.PresignGet(ctx, "container", "file.pdf", 15*time.Minute)
    uploadURL, _ := ps.PresignPut(ctx, "container", "upload.zip", time.Hour)
}

SAS URL generation requires shared key credentials (account key).

RangeDriver

Read specific byte ranges:

if rd, ok := t.Driver().(driver.RangeDriver); ok {
    reader, _ := rd.GetRange(ctx, "container", "video.mp4", 1000, 1000)
    defer reader.Close()
}

API05

Constructor

func New() *AzureDriver

Creates a new Azure driver instance.

Client

func (d *AzureDriver) Client() *azblob.Client

Returns the underlying *azblob.Client for advanced Azure Blob operations.

Unwrap

func Unwrap(accessor interface{ Driver() driver.Driver }) *AzureDriver

Extract the *AzureDriver from a Trove handle:

azdrv := azuredriver.Unwrap(troveInstance)
if azdrv != nil {
    raw := azdrv.Client()
}

Driver Registration

The Azure driver auto-registers via init():

factory, ok := driver.Lookup("azure")
drv := factory()

Azurite Setup for Development06

Run Azurite locally with Docker:

docker run -d --name azurite \
  -p 10000:10000 \
  mcr.microsoft.com/azure-storage/azurite \
  azurite-blob --blobHost 0.0.0.0

Then connect using the well-known development account:

drv := azuredriver.New()
drv.Open(ctx, "azure://devstoreaccount1/testcontainer?key=Eby8vdM02xNOcqFlqUwJPLlmEtlCDXJ1OUzFT50uSRZ6IFsuFq2UVErCz4I6tq/K1SZFPTOtr/KBHBeksoGMGw==&endpoint=http://127.0.0.1:10000/devstoreaccount1")

Integration Tests07

# Start Azurite
docker run -d -p 10000:10000 mcr.microsoft.com/azure-storage/azurite azurite-blob --blobHost 0.0.0.0

# Run integration tests
cd drivers/azuredriver
go test -tags integration -v ./...

Environment variables:

Variable	Default	Description
`AZURE_ENDPOINT`	`http://127.0.0.1:10000/devstoreaccount1`	Azure Blob endpoint
`AZURE_ACCOUNT_NAME`	`devstoreaccount1`	Storage account name
`AZURE_ACCOUNT_KEY`	Azurite dev key	Storage account key

Limitations08

SAS URL generation requires shared key credentials (not available with connection strings lacking a key)
Block blob staging is limited to 50,000 blocks per blob
Container names must be 3-63 characters, lowercase letters, numbers, and hyphens

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