UploadStreamToBlockBlob: blob access conditions are ignored

[ItalyPaleAle]

Bug Report

• import path of package in question: github.com/Azure/azure-sdk-for-go/sdk/storage/azblob v0.3.0
• output of go version: go version go1.17.5 linux/arm64

(This is a spin-off from #17131 which identified the error as something different than I originally thought)

You can repro with the code below (fill the constants at the top):

package main

import (
	"context"
	"fmt"
	"io"
	"math/rand"
	"os"
	"time"

	"github.com/Azure/azure-sdk-for-go/sdk/azcore/policy"
	"github.com/Azure/azure-sdk-for-go/sdk/storage/azblob"
)

// Set these
const account = "***"
const accessKey = "***"

// For these tests, I used 2 random images from Unsplash (because those are relatively large files and are free)
// Feel free to use any other file name here
const testFile1 = "dave-goudreau--W_vDl5Ll8M-unsplash.jpg"
const testFile2 = "katharina-bill-dSc2aoQmaZk-unsplash.jpg"

func main() {
	rand.Seed(time.Now().UnixNano())

	containerClient, err := setupContainer("c" + RandString(5))
	if err != nil {
		panic(err)
	}

	in := openFile(testFile1)
	defer in.Close()

	err = uploadToAzure(
		containerClient,
		"testblob",
		in,
		nil,
	)
	if err != nil {
		panic(err)
	}

	// Upload again: this should return an error
	in = openFile(testFile2)
	defer in.Close()
	err = uploadToAzure(
		containerClient,
		"testblob",
		in,
		nil,
	)
	if err == nil {
		panic("Expected error, got nil")
	}
	fmt.Println(err)
}

const letters = "abcdefghijklmnopqrstuvwxyz0123456789"

func RandString(n int) string {
	b := make([]byte, n)
	for i := range b {
		b[i] = letters[rand.Intn(len(letters))]
	}
	return string(b)
}

func openFile(name string) io.ReadCloser {
	in, err := os.Open(name)
	if err != nil {
		panic(err)
	}
	return in
}

func setupContainer(container string) (*azblob.ContainerClient, error) {
	storageURL := fmt.Sprintf("https://%s.blob.core.windows.net", account)
	cred, err := azblob.NewSharedKeyCredential(account, accessKey)
	if err != nil {
		return nil, err
	}
	service, err := azblob.NewServiceClientWithSharedKey(storageURL, cred, &azblob.ClientOptions{
		Telemetry: policy.TelemetryOptions{
			Disabled: true,
		},
	})
	if err != nil {
		return nil, err
	}
	containerClient := service.NewContainerClient(container)
	_, err = containerClient.Create(context.Background(), &azblob.CreateContainerOptions{
		Access: nil,
	})
	if err != nil {
		return nil, err
	}
	return &containerClient, nil
}

func uploadToAzure(containerClient *azblob.ContainerClient, name string, in io.Reader, metadata map[string]string) error {
	blob := containerClient.NewBlockBlobClient(name)
	ifNoneMatch := "*"
	opts := azblob.UploadStreamToBlockBlobOptions{
		BufferSize: 5 * 1024 * 1024,
		MaxBuffers: 2,
		BlobAccessConditions: &azblob.BlobAccessConditions{
			ModifiedAccessConditions: &azblob.ModifiedAccessConditions{
				IfNoneMatch: &ifNoneMatch,
			},
		},
		Metadata: metadata,
	}
	res, err := blob.UploadStreamToBlockBlob(context.Background(), in, opts)
	if err != nil {
		return err
	}
	fmt.Println(res.RawResponse.StatusCode)

	return nil
}

Expected result:

• First file should be uploaded correctly
• Second file should fail to be uploaded because of the ifNoneMatch condition set to "*"
• Second invocation of uploadToAzure should return an error, and the status code shown from the second method should not be 2xx

Actual result:

• First file is uploaded then overwritten by the second file
• uploadToAzure never returns an error, and status code is always 2xx

CC: @zezha-msft

[mohsha-msft]

Hey @ItalyPaleAle ,

Thanks for reaching out!
I have fixed this issue and will be releasing it in the next release.

[ItalyPaleAle]

Thanks for the update! This is great news

[mohsha-msft]

Hey @ItalyPaleAle ,
azblob v0.4.0 is now publically available. I have fixed the issue here and here.

Please reach out and reopen the issue if it still persists.

Thanks a lot for your feedbacks!