Best Way to host dynamic image with Azure - azure

I am working on a website where I need to dynamically host images. My intention is to host the images with full URL.
I tried CDN but come to know it has a limitation of that image will only be available 15 mins after upload.
Other options is Blob storage, when I read the document it says "Block blobs" are most ideal for image and media content. Therefore, I am trying to use that.
So, I've following questions:
What is the best way to host images on Azure for such requirements?
If I use Blob storage then how can I get the full URL so that I can that URL to load images in my product?

There really isn't a best way to store images. Some people store them in blob storage (as you referenced), some go with database engines... But, since you asked specifically about how to interact with blob storage and URI's:
All blobs are referenced by uri: http(s)://storagename.blob.core.windows.net/containername/blobname
You can set every blob to private or public (whether at blob or container level), and then either return URI's to your user/webpage (if public) or generate a Shared Access Policy or Shared Access Signature to temporariliy grant access to a private blob (I'll leave that as an exercise for you to look up).
It's completely up to you to create containers and blobs as needed. How you find a blob later is also up to you, so you'll need to think about how you store their names or their URIs (e.g. in a database table somewhere). You can always iterate through containers to search for a given blob, but that is time-consuming, vs direct-retrieval (again, assuming you've stored the URI as metadata somewhere in a database).

Related

Serving Files From Azure Storage

I have a simple need, but there are so many azure options, I am not sure where to start.
I have a AppService (website) on azure from which I want to serve static PDFs for download. In other words, there is a training page on the website, and on this page, I want to have url to the PDF to download it.
But I don't want the PDF's to be a part of the AppService files, I want them in storage so they are a separate from the website files.
How should this be done?
What I have found so far is: Azure Blob storage, but it's not clear to me how to use those with a URL. The samples look like they are using code to download instead of a public URL.
I have also looked at Azure CDN, but that seems like more than I am looking for. Just need a simple location to store and download files.
You can make the blob container public so anyone with the link can download the file.
In this case you can just link to the file or return a 302 redirect from your app to the link, which also initiates the download.
Another option is to use SAS tokens.
These temporary tokens are generated using your storage account access key,
and are attached to the URL.
You can then give this final URL in the link to allow the user to download the file.
In this option the container can be kept private, and you control who can access what.
Now the token is only valid until it expires (you decide this time), so a user could give the link to another person and they could also download the document within that time.
The third option is to pipe the files through your app to the user.
Download the file from your back-end and then stream it to the user for download.
This option takes more resources on your back-end as threads and IO are used there for each download.
This option is the most secure as you can control who can download what.
you can upload your PDFs to Azure Blob storage into a special container (e.g. download) and make that container and content public in either of two ways:
public read access for blobs only: Blobs within the container can be read by anonymous request, but container data is not available. Anonymous clients cannot enumerate the blobs within the container.
Full public read access: All container and blob data can be read by anonymous request. Clients can enumerate blobs within the container by anonymous request, but cannot enumerate containers within the storage account.
Then they are accessible by a URL like https://yourStor.blob.core.windows.net/download/train1.pdf
To expand on the accepted answer
Create a Storage Account, such as mystorage
In the storage account, create a container, such as mycontainer
On the container, set the Access Policy to Blob (Anonymous read access for blobs only).
Upload your file, such as myfile.txt to the container.
View the file Properties. It will show the URL to the file which is in this format: https://mystorage.blob.core.windows.net/mycontainer/myfile.txt
Note that the URL is case sensitive.

Uploading and accessing images with Azure

I want to upload some static images that I will later access via some mobile apps. I have an Azure Account that I rarely use so I thought that was the best place and therefore I uploaded them to a "File Share" within Azure Storage.
I naievely thought I could them just access those files via a simple web request url
https://myplace.file.core.windows.net/app/images/bnb/shop/bugle_200_2.jpg
All this gets me is a BadRequest error. I realize that I could create a Shared Access Signature (SAS) for every file but that seems total overkill.
Is there a better Azure feature to use? I do not want to have to use the Azure APIs to get at these files
Adding a few more points to #CtrlDot's excellent answer.
I completely agree that you should use Blob Storage for storing static content.
On the container permissions, I would actually recommend setting the permission (ACL) to Blob so that user can only view the blob they have the URL for and not enumerate all blobs in a container (setting container ACL to Container will enable the users to list blobs in a container which may not be a desired behaviour for you).
Other than these, there are two distinct advantage of using Blob Storage:
Custom domain: You can map blob storage to a custom domain (e.g. static content.mywebsite.com) and use that to serve the content instead of using Azure Blob Storage standard endpoint (your account.blob.core.windows.net).
CDN: You can also CDN enable your blob storage endpoint. The content will then be replicated across many CDN nodes spread throughout the globe and will be served from a node near to your user thus improving the user experience.
I think the service you should be looking to use is blob storage, not file storage. File storage, as per the documentation, is meant more for SMB shares.
When you setup Azure blob storage, you have a couple of different options. If there is nothing sensitive/secure about these static images, you could consider making a public container and simply accessing the files like that.
If you require authentication, then you need to either use azure storage access keys, or azure storage access tokens. Of the two, the storage access tokens are by far the most secure.
You wouldn't need to create a SAS token for each file, rather, grant it read permission to the container. Once again, you will have to tailor this to the security/sensitivity needs of your application.

Windows Azure blob storage & URL rewrite

What I need is to rewrite URL for the requested blob, i.e. instead of
http://myaccount.blob.core.windows.net/clients/{client-name}/images/imagefile.jpg
should be served
http://myaccount.blob.core.windows.net/clients/images/imagefile.jpg
The client name in the URL is a request to have SEO URL, as file names are unique and I'd like to have blob name as
images/imagefile.jpg instead of
{client-name}/images/imagefile.jpg and use something like URL rewrite in IIS.
It becomes a pain if the client changes it's name as I can't rename a blob I have to create copy and delete the old blob. It may take more than a minute which we can't afford.
You can't use anything like URL Rewrite for the storage accounts. You can only have custom domain mapped to your storage account. For example instead of referencing blobs with: http://myaccount.blob.core.windows.net/... you could map them to http://img.yourdomain.com/... And you could also use the Azure CDN for better performance and user experience!
Moreover, if you do care about SEO, you have to also think on not just "rename" the blob but also use HTTP 301 redirect from the old blob to the new one. Which also is impossible with Azure storage service. I suggest that you use client-id instead of client-name
UPDATE
You "can" reanme the blobs, simialry to the way you would rename files. Given your requirement - if you want to "quickly" rename a lot of images, you have to write simple "service" anyway, because I can't figure out another way to rename 1000s of files on the file system either. With the blobs, although beeing remote it will be almost the same. And you are wrong that you have to save the blob on the machine. There is new feature (method on the CloudBlob instance) since November'2011 release (I think), named CopyFromBlob. Here is an example of how to rename blobs.. This way you can easily move blobs even around different account without the need to first download the content. Yes, it may take a bit longer than with a local file system. But still this is a fair-enough solution.
Think about what the Azure Storage is. A massively scalable, reliable storage as a service. You have 100TB (subject to increase if required), with 3 copies locally + one copy in another geo region. A CDN support for this massive storage with more than 24 nodes worldwide. I don't think renaming is something of top need.

What is the best strategy for using Windows Azure as a file storage system - with http download capabilities

I need to store multiple files that users upload, and then provide these users with the capability of accessing their files via http. There are two key considerations:
- Storage (which is my primary concern here)
- Security (which let's leave aside for now)
The question is:
What is the most cost efficient and performant way of storing all these files and giving access to them later? I believe the answer is:
- Store files within Azure Storage Account, and have a key that references them in an SQL Azure database.
I am correct on this?
Is a blob storage flat? Or can I create something like folders inside it to better organize my files?
The idea of using SQL Azure to store metadata for your blobs is a pretty common scenario, which allows you to take advantage of SQL for searching, and blobs for storage.
Blobs are organized by container. So you'd have something like:
http://mystorage.blob.core.windows.net/mycontainer/myfile.doc
You can also simulate a hierarchy using a delimiter, but in reality there's just container plus blob.
If you keep the container or blob private, the user would either have to go through your web front end (or web service), or you'd have to provide them with a special URL with a Shared Access Signature appended, which is a time-limited URL.
I would recommend you to take a look at BlobShare Sample which is a simple file sharing application that demonstrates the storage services of the Windows Azure Platform, together with the authentication and authorization capabilities of Access Control Service (ACS). The full sample code is located at following link:
http://blobshare.codeplex.com/
You can use this sample code immediately, just by adding proper reference to your Windows Azure Account credentials. The best thing with this sample is that you can provide blob access directly through Access Control Services. You can also modify the code to add SAS support as well as blob download from public containers. Once you have it working and understood the concept you can tweak to make it the way you would want.

Where to store things like user pictures using Azure? Blob Storage?

I have just migrated a project of mine for test cases to Microsoft's azure.
But for functionalities similar to an avatar upload I need write access to the files on the harddrive. But this is a cloud, so this is not possible.
How can I build such functionalities instead? Should I use the Blob Storage or is there a better solution?
Does it make sense to store all website images (f.e. layout images) in the Blob Storage? So I would have a Cookie-free Domain for my static content?
Blob storage is definitely the place to put dynamic images like avatars. While you can write to the disk on the VM you'll be running in, you can't rely on this to be present - if your app gets moved off to another machine (which could happen for any number of reasons) this storage will be erased.
One thing you could do is store your images in blob storage, and cache them on the local VM disk (using the standard file IO mechanisms). This way you'll get pretty good performance and will save on a few storage transactions while still making sure you're not storing in volatile storage.
If you've got static images which will be completely static, these are just bundled with your application and can be referenced like a normal file. But, if you will ever need to change them, you'd need to redeploy the application - so only use this technique for images which won't need to change.
Be aware there are two types of Blobs in Windows Azure: Block Blobs and Page Blobs. Block Blobs are appropriate for media file serving, whereas Page Blobs are optimized for other work patterns.
Also consider use of the Azure Content Distribution Network (CDN) for lowering latency to clients.
Azure also has streaming capabilities which work in concert with Silverlight Smooth Streaming (http://blog.smarx.com/posts/smooth-streaming-with-windows-azure-blobs-and-cdn if interested).
"Does it make sense to store all website images (f.e. layout images) in the Blob Storage? So I would have a Cookie-free Domain for my static content?"
Yes I think so - this is what I'm rolling out right now actually.

Resources