implement ContentServerDataStore for azure blob storage too

[xelat09]

Hi & Happy new year

Implement ContentServerDataStore for azure blob storage too, tests with azurite+azure blob are ok.
Incomplete range requests (Range: bytes=100- ) are not supported, hope that's ok

Regards

[Acconut]

Thank you very much for this PR, it's greatly appreciated! I had a brief first look and left a few comments. Let me know what you think!

[Acconut]

Can we also forward headers like If-Match to Azure for supporting conditional requests? This is done by the s3store as well:

tusd/pkg/s3store/serve_content.go

Lines 31 to 48 in a50bc42

	if val := r.Header.Get("If-Match"); val != "" {
	input.IfMatch = aws.String(val)
	}
	if val := r.Header.Get("If-None-Match"); val != "" {
	input.IfNoneMatch = aws.String(val)
	}
	if val := r.Header.Get("If-Modified-Since"); val != "" {
	t, err := http.ParseTime(val)
	if err == nil {
	input.IfModifiedSince = aws.Time(t)
	}
	}
	if val := r.Header.Get("If-Unmodified-Since"); val != "" {
	t, err := http.ParseTime(val)
	if err == nil {
	input.IfUnmodifiedSince = aws.Time(t)
	}
	}

Or does Azure Blob Storage not support conditional requests?

[Acconut]

Can we forward response headers like Content-Type from Azure's response? Similar to how its done in the s3store:

tusd/pkg/s3store/serve_content.go

Lines 95 to 128 in a50bc42

	// Add Accept-Ranges,Content-*, Cache-Control, ETag, Expires, Last-Modified headers if present in S3 response
	if result.AcceptRanges != nil {
	w.Header().Set("Accept-Ranges", *result.AcceptRanges)
	}
	if result.ContentDisposition != nil {
	w.Header().Set("Content-Disposition", *result.ContentDisposition)
	}
	if result.ContentEncoding != nil {
	w.Header().Set("Content-Encoding", *result.ContentEncoding)
	}
	if result.ContentLanguage != nil {
	w.Header().Set("Content-Language", *result.ContentLanguage)
	}
	if result.ContentLength != nil {
	w.Header().Set("Content-Length", strconv.FormatInt(*result.ContentLength, 10))
	}
	if result.ContentRange != nil {
	w.Header().Set("Content-Range", *result.ContentRange)
	}
	if result.ContentType != nil {
	w.Header().Set("Content-Type", *result.ContentType)
	}
	if result.CacheControl != nil {
	w.Header().Set("Cache-Control", *result.CacheControl)
	}
	if result.ETag != nil {
	w.Header().Set("ETag", *result.ETag)
	}
	if result.ExpiresString != nil {
	w.Header().Set("Expires", *result.ExpiresString)
	}
	if result.LastModified != nil {
	w.Header().Set("Last-Modified", result.LastModified.Format(http.TimeFormat))
	}

[Acconut]

You mentioned that "Incomplete range requests (Range: bytes=100- ) are not supported". From the SDK's documentation, it seems to be possible to let the count be zero and get the entire resource starting at the offset:

https://pkg.go.dev/github.com/Azure/azure-sdk-for-go/sdk/storage/[email protected]/internal/exported#HTTPRange

An HTTPRange which has an offset and zero value count indicates from the offset to the resource's end.

Could you implement support for this?

[xelat09]

yeah, as suggested, azure supports all those headers too. please have a look, i gave it a new try. tests with azurite do work..

do you see anything else missing?

[Acconut]

Thank you very much for the quick updates! The handler is the request headers looks much better yet. Could you also have a look at the failing tests at https://github.com/tus/tusd/actions/runs/12736636713/job/35496766413?pr=1234? Talking about tests, it would be great to have some tests for ServeContent in azurestore as well. For inspiration you can use s3store's tests: https://github.com/tus/tusd/blob/main/pkg/s3store/serve_content_test.go

[Acconut]

Can you please run go fmt to address the formatting inconsistencies?

[Acconut]

Suggested change

	return nil
	return errors.New("azurestore: ServeContent is not implemented for InfoBlob")

Please return an error here so we notice it early if this method is accidentally called.

[Acconut]

Can we forward response headers like Content-Type from Azure's response? Similar to how its done in the s3store:

tusd/pkg/s3store/serve_content.go

Lines 95 to 128 in a50bc42

	// Add Accept-Ranges,Content-*, Cache-Control, ETag, Expires, Last-Modified headers if present in S3 response
	if result.AcceptRanges != nil {
	w.Header().Set("Accept-Ranges", *result.AcceptRanges)
	}
	if result.ContentDisposition != nil {
	w.Header().Set("Content-Disposition", *result.ContentDisposition)
	}
	if result.ContentEncoding != nil {
	w.Header().Set("Content-Encoding", *result.ContentEncoding)
	}
	if result.ContentLanguage != nil {
	w.Header().Set("Content-Language", *result.ContentLanguage)
	}
	if result.ContentLength != nil {
	w.Header().Set("Content-Length", strconv.FormatInt(*result.ContentLength, 10))
	}
	if result.ContentRange != nil {
	w.Header().Set("Content-Range", *result.ContentRange)
	}
	if result.ContentType != nil {
	w.Header().Set("Content-Type", *result.ContentType)
	}
	if result.CacheControl != nil {
	w.Header().Set("Cache-Control", *result.CacheControl)
	}
	if result.ETag != nil {
	w.Header().Set("ETag", *result.ETag)
	}
	if result.ExpiresString != nil {
	w.Header().Set("Expires", *result.ExpiresString)
	}
	if result.LastModified != nil {
	w.Header().Set("Last-Modified", result.LastModified.Format(http.TimeFormat))
	}