Last updated on: 2018-02-06
Authored by: Rackspace Support
This article provides general information about sharing server images and provides details about how image sharing works in the Cloud Control Panel.
Image sharing enables you to use custom images created by other Rackspace cloud users and to create custom images to share with others. Following are example scenarios in which image sharing would be helpful:
Here’s a quick overview of some aspects of image sharing. To keep things clear, we’ll refer to the person who’s created an image to share as the producer, and the person who wants to use that image as the consumer. (Putting it another way, the producer is the share-er, and the “consumer” is the share-ee.)
Support for shared images: Shared images are considered nonstandard images (for more information, see Standard and Non-Standard Images).
Note: Regardless of the service level that you are subscribed to, we cannot guarantee supportability of these images. Your service level agreement (SLA) on cloud servers that use shared images extends only to the physical infrastructure on which the shared image resides.
Visibility of shared images (anti-spam): If someone shares an image with you, you can see it within your list of bootable images only if you want to. Only images that you have specifically accepted appear in your image list. If you don’t want an image shared with you to clutter up your image list, you always have the option to reject it.
Image sharing is account-to-account: If you have an account in which you’ve created additional users, users who have been assigned the appropriate RBAC role can perform the following actions:
Image sharing is regional: In the Rackspace Cloud, each image exists in a particular region. If a producer has an image in the IAD region and shares it with a consumer, the consumer can use that image in the IAD region.
A shared image is not a copy: If a producer shares an image with you, you are using the producer’s actual image, not a copy. The benefit of this is that you don’t have to pay for storage for that image. The disadvantage is that if the producer decides to stop sharing the image with you, you no longer have access to the image.
Tip: If a particular shared image is useful to you, create your own image from a server that is booted from the shared image.
Image sharing is also available in the Cloud Images API: If you share an image with someone who doesn’t use the Cloud Control Panel, you might want to notify them that the image is available. Because of the anti-spam feature, the image won’t display in their image list.
For more information, see the image sharing section of the Cloud Images FAQ.
The abilities to share and accept images are controlled by RBAC for Cloud Images. The roles are briefly described as follows:
For more information about Cloud Images RBAC, see the How To article Detailed Permission Matrix for Cloud Images.
Use the following considerations and steps to share server images.
Before you share an image, consider the following questions:
Does the image contain any software whose license prohibits distribution?
By sharing an image, you are distributing the software on it. It is your responsibility to ensure that such distribution is allowed by each vendor’s software license.
Does the image contain any of your sensitive information?
Before sharing an image, boot a new server from it in your own account. Log in to the server and verify that the image doesn’t contain any private encryption keys or other sensitive information.
Is there any malicious software on the image?
You are expected to follow the Rackspace Acceptable Use Policy (AUP) with regard to the type of software included on images. Ensure that you’re familiar with the AUP before you share an image.
When your image is ready to share, use one of the following methods in the Control Panel to share it:
In the Saved Images list (Servers > Saved Images), click the gear icon to the left of the image name, and then select Share Image.
When the sharing dialog box opens, the image sharing interface in the Cloud Control Panel is optimized for the following common sharing scenarios:
Sharing an image with another account to which you have legitimate access:
In other words, you have legitimate access to the username and password of a user on that account whose RBAC role is at least as powerful as cloudImages:admin. For example, you are in the IT department of a company, and you set up accounts for some other departments. You prepared some images for these departments, and now you want to make the images available for people in these departments to use.
Sharing an image with another customer:
For example, you are the hobbyist described earlier. The members of your exotic OS users' group gave you their account numbers, but they aren’t going to give you their usernames and passwords.
Enter the appropriate information for your scenario, and click Share Image.
The Image Sharing table at the bottom of the Image Detail page is populated with a row containing information about this sharing event. You can see which users have accepted or rejected your sharing request, and for which users the request is pending acceptance.
To keep the Rackspace Cloud a friendly place, observe the following suggestions:
As explained earlier, to prevent spam in your image list, you must accept an image before it displays in your image list. You can find out whether someone has shared an image with you in the following places in the Cloud Control Panel:
If you accept an image, the notification disappears and the image displays in your list of saved images. On the Saved Images page, the text Shared Image displays in the Source column. In the image selector on the Create Server page, select Saved Images and then Shared Images.
If you reject the image, it does not display in your image list, and the notification disappears.
If you don’t want to boot from the image now and want to postpone the decision to accept or reject the image, close the dialog box and the notification remains.
If you accept an image and then decide later that you don’t want it, you can reject it by using the following steps:
If you reject an image and decide later that you want it, you must notify the image producer and ask that the image be re-shared with you.
After you accept a shared image, you can use it to boot a server by using your normal workflow. However, we encourage you to consider the following information before booting a server from a shared image:
Shared images are nonstandard images. For more information, see Standard and Non-Standard Images. For servers booted from nonstandard images, you can expect that we ensure that host servers are functioning properly and that the API availability meets the SLA.
However, we cannot promise to support servers booted from shared images in the same way that we support servers booted from Rackspace base images. We create the base images ourselves and know exactly what’s on them, whereas the point of shared images is to empower our customers to use images that we haven’t implemented. Although you can expect support, you can’t expect our support staff to know the intricacies of exotic OS, for example, in the same way that they know CentOS.
Verify that there are no strange users with login privileges in /etc/passwd and that there aren’t any strange SSH keys preinstalled on the server.
Build critical infrastructure components only from images created by people that you trust. If you suspect that an image shared with you contains malware or is behaving strangely, you can report such suspicious activities to Rackspace Support and to email@example.com.
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