[Kimchi-devel] [RFC] ISO pool: Support to download ISO from URL

[Royce Lv]

On 2014年08月19日 08:42, Crístian Viana wrote:
> The following API changes should be made to implement the remote 
> download ISO feature:
>
> 1) POST /storagepools/ISO/storagevolumes/download {'url': 
> <http|https|ftp|ftps>, 'name': <volume name>}
> Description: Starts downloading a remote ISO image to Kimchi's storage 
> pool.
> Parameters:
> 'url': specifies where the image is hosted. Required.
> 'name': specifies the name of the local file when the download 
> finishes. If this parameter is omitted, Kimchi will try to use the 
> same file name as the remote file. Optional.
> Return codes:
> 200: the remote URL is valid and the download started successfully.
> 400: the remote URL is not valid;
Cristian,

Thanks for this comprehensive and detailed RFC which we can take as a 
good example! Some suggestion according to me below:
1. As for me, if download/upload is a time consuming task, we may want 
to use AsyncTask to track it.
So for POST /storagepools/ISO/storagevolumes/download we may want to 
return 202 and a 'task_id' in the response data.

2.To query status, pause and cancel the download, the target will be the 
task:
POST /tasks/download-task-id/cancel
This may require enhancement of tasks API.

> the provided 'name' is already in use (this error shouldn't happen if 
> 'name' is omitted).
> the storage pool doesn't have enough free space to hold the remote file.
> Return data:
> {'name': <vol-name>}
>
> 2) POST /storagepools/ISO/storagevolumes/download/pause {'name': 
> <volume name>}
> Description: Pauses a remote ISO download.
> Parameters:
> 'name': the remote volume name to be paused. Required.
> Return codes:
> 200: 'name' is an ongoing download file and the operation was paused 
> successfully.
> 400: 'name' is an invalid volume name (doesn't exist / isn't an 
> ongoing download);
> download referred by 'name' cannot be paused.
> Return data:
> {}
>
> 3) POST /storagepools/ISO/storagevolumes/download/resume {'name': 
> <volume name>}
> Description: Resumes a paused remote ISO download.
> Parameters:
> 'name': the remote volume name to be resumed. Required.
> Return codes:
> 200: 'name' is a paused download file and the operation was resumed 
> successfully.
> 400: 'name' is an invalid volume name (doesn't exist / isn't a paused 
> download).
> Return data:
> {}
>
> 4) POST /storagepools/ISO/storagevolumes/download/cancel {'name': 
> <volume name>}
> Description: Cancels a remote ISO download.
> Parameters:
> 'name': the remote volume name to be canceled. Required.
> Return codes:
> 200: 'name' is an ongoing download file and the operation was canceled 
> successfully. Whatever data has been downloaded so far should be deleted.
> 400: 'name' is an invalid volume name (doesn't exist / isn't an 
> ongoing download).
> Return data:
> {}
>
> 5) POST /storagepools/ISO/storagevolumes/download/status {'name': 
> <volume name>}
> Description: Provides status of a remote ISO download.
> Parameters:
> 'name': the remote volume name. Required.
> Return codes:
> 200: 'name' is a download file and its status information was returned 
> successfully.
> 400: 'name' is an invalid volume name (doesn't exist / isn't a remote 
> download).
> Return data:
> {'name': <volume name>, 'status': [downloading|paused], 'total_size': 
> <size in bytes>, 'downloaded_size': <size in bytes>}
>
> I tried to put together the feedback given in another e-mail thread, 
> especially by Aline, Royce and Yu Xin Huo, along with some ideas of my 
> own. This RFC doesn't support choosing a different storage pool other 
> than "ISO" to host the downloaded files. If we're doing this, wel need 
> to update this new API accordingly.
>
> The implementation details will be discussed later.
>
> Please share your feedback with us.
>
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