Is it possible to generate a public URL for a file on an EMC Atmos cloud storage system?

Question

I have an application that allows users to customize a website with CSS and other items. Upon the creation of these files, they are stored on Amazon S3 as being publicly readable. Therefore I have always been able refer to them with a static url that did not require me to first connect to S3 to generate a URL.

We have moved all of the files to an EMC Atmos system that is located within our hosting company's datacenter. I know how to generate shareable URLs from Atmos, but only by first establishing a connection. Is there a way on Atmos to set system metadata on an object so that it can be referred to with a static URL?

Answer 1

You don't need to connect to Atmos to generate a shareable URL. The generation of the shareable URL always happens client-side; it doesn't happen over HTTP.

Atmos system metadata is always immutable. You can generate a "static URL" using a shareable URL with an expiration set to something in the distant future.

Answer 2

EMC Atmos does not need an HTTP/HTTPS connection to generate a shareable URL. It does make an HTTP connection to generate the file, but it can be done by the end user of the file stored on the cloud.

To create the URL, a signature is made on the application client-side (no HTTP connection needed). The reason is because a unique signature is generated.

To send the signature, you either put the signature in the URL:

$url = "http://$server$resource?uid=$uid&expires=$expires&signature=$signature";

Or instead of putting the signature in the URL, you send it through the REST API by posting an HTTP header of x-emc-signature.

So, once you have that URL generated, you can send it to somebody else via an email or text, which they can click on later and it will be valid, as long as the URL has not expired.

Once EMC Atmos verifies the signature, it sends the download to the client. Note that a server with a system clock that is off by more than five minutes will have problems generating shareable URL's, so keep the time in sync on the application generating the shareable URL's by using an NTP daemon.

So, to clarify, EMC Atmos does not need an HTTP connection to your cloud storage provider. The HTTP connection is done when the file is first requested. At that point the file becomes available publicly.