Re: Add new API: createImage()

On 09/21/2011 04:58 AM, Adam Litke wrote:
>  As it currently stands, images are created implicitly when a volume
> is created
>  using a new imageUUID.  Although this is practical for the current use cases, it
>  doesn't present a semetrical API.  Other vdsm objects have create/delete
>  methods.i
>
>  Furthermore, it preents challenges when trying to model VDSM in a REST API.
>  Let's say I want to create a new disk for a VM.  I would want to issue the
>  following sequence of commands:
>
>  POST ->  /vdsm-api/storagedomains/<sdUUID>/images/create
>  <- HTTP/202 Accepted: /vdsm-api/tasks/<task-uuid>
>  GET ->  /vdsm-api/tasks/<task-uuid>
>  <- HTTP/200 OK: /vdsm-api/storagedomains/<sdUUID>/images/<imgUUID>
>  POST -> 
> /vdsm-api/storagedomains/<sdUUID>/images/<imgUUID>/volumes/create
>  <- HTTP/202 Accepted: /vdsm-api/tasks/<task-uuid>
>  GET ->  /vdsm-api/tasks/<task-uuid>
>  <- HTTP/200 OK:
>       
> /vdsm-api/storagedomains/<sdUUID>/images/<imgUUID>/volumes/<volUUID>
>
>  The only way to support this pattern is to allow for the explicit creation of an
>  image with an empty volume chain.
>
>  Signed-off-by: Adam Litke&lt;agl(a)us.ibm.com&gt;
>
>  diff --git a/vdsm/storage/spm.py b/vdsm/storage/spm.py
>  index 849b9d2..1222752 100644
>  --- a/vdsm/storage/spm.py
>  +++ b/vdsm/storage/spm.py
>  @@ -820,6 +820,23 @@ class SPM:
>                repoPath = os.path.join(self.storage_repository, spUUID)
>                image.Image(repoPath).multiMove(srcDomUUID, dstDomUUID, imgDict, vmUUID,
> force)
>
>  +    def createImage(self, sdUUID, spUUID, imgUUID):
>  +        """
>  +        Create a new, empty image
>  +
>  +        :param sdUUID: The UUID of the storage domain that contains the images.
>  +        :type sdUUID: UUID
>  +        :param spUUID: The UUID of the storage pool that contains the images.
>  +        :type spUUID: UUID
>  +        :param imgUUID: The UUID of the image you want to delete. 
why delete?
Y.

>  +        :type imgUUID: UUID
>  +
>  +        """
>  +        hsm.HSM.getPool(spUUID) #Validates that the pool is connected. WHY?
>  +        hsm.HSM.validateSdUUID(sdUUID)
>  +        repoPath = os.path.join(self.storage_repository, spUUID)
>  +        image.Image(repoPath).create(sdUUID, imgUUID)
>  +        return dict(uuid=imgUUID)
>
>        def deleteImage(self, sdUUID, spUUID, imgUUID, postZero, force):
>            """
>  @@ -1470,6 +1487,18 @@ class SPM:
>                imgUUID, volumes, misc.parseBool(postZero), misc.parseBool(force)
>            )
>
>  +    def public_createImage(self, sdUUID, spUUID, imgUUID):
>  +        """
>  +        Create a new, empty image
>  +        """
>  +        argsStr = "sdUUID=%s, spUUID=%s, imgUUID=%s" % \
>  +                  (str(sdUUID), str(spUUID), str(imgUUID))
>  +        vars.task.setDefaultException(se.ImagePathError(argsStr))
>  +        hsm.HSM.getPool(spUUID) #Validates that the pool is connected. WHY?
>  +        hsm.HSM.validateSdUUID(sdUUID)
>  +        misc.validateUUID(imgUUID, 'imgUUID')
>  +        vars.task.getSharedLock(STORAGE, sdUUID)
>  +        self._schedule("createImage", self.createImage, sdUUID, spUUID,
> imgUUID)
>
>        def public_deleteImage(self, sdUUID, spUUID, imgUUID, postZero=False,
> force=False):
>            """