In Synnefo, an image is loaded as a file to the storage service (Pithos+), and then is registered to the image service (Plankton). The image location at the storage server is unique through out a deployment and also necessary for the image to exist.
The image location format at user level:
<container>:<object path>
e.g.,:
pithos:debian_base3.diskdump
Note
The image API requires the image location in the form
pithos://<user uuid>/<container>/<object path>
The translation between the two formats is handled internally by kamaki. The latest format is still acceptable by kamaki due to backward compatibility but it is going to be deprecated from kamaki 0.12 and on.
Let the image file debian_base3.diskdump be a debian image located at the current directory.
Upload the image to container pithos
[kamaki]: file upload debian_base3.diskdump pithos
Uploading /home/someuser/debian_base3.diskdump --> pithos:debian_base3.diskdump
Done
[kamaki]:
Register the image object with the name ‘Debian Base Alpha’
[kamaki]: image register 'Debian Base Alpha' pithos:debian_base3.diskdump
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: 7h1rd-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump
name: Debian Base Alpha
owner: s0m3-u53r-1d
properties:
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
Metadata file uploaded as pithos:debian_base3.diskdump.meta (version 1352)
[kamaki]:
Note
The image register command automatically creates a meta file and uploads it to the same location as the image. The meta file can be downloaded and reused for more image registrations.
Another way to perform the two operations above is to call /image register with the - -upload-image-file argument. This single operation will upload the image file and then register it as an image, and is equivalent to manually calling /file upload and /image register.
In other words, the preceding and following command sequences are equivalent.
[kamaki]: image register 'Debian Base Alpha'
pithos:debian_base3.diskdump
--upload-image-file='debian_base3.diskdump'
[kamaki]:
Read the metafile
[kamaki]: file cat pithos:debian_base3.diskdump
{
"status": "available",
"name": "Debian Base Gama",
"checksum": "3cb03556ec971f...e8dd6190443b560cb7",
"id": "7h1rd-1m4g3-1d2",
"updated-at": "2013-06-19 08:01:00",
"created-at": "2013-06-19 08:00:22",
"properties": {},
"location": "pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump",
"is-public": "False",
"owner": "s0m3-u53r-1d",
"disk-format": "diskdump",
"size": "903471104",
"deleted-at": "",
"container-format": "bare"
}
[kamaki]:
List all images, then list only images owned by the user with id s0m3-u53r-1d
[kamaki]: image list
f1r57-1m4g3-1d Debian Base Alpha
container_format: bare
disk_format: diskdump
size: 474066944
status: available
53c0nd-1m4g3-1d Beta Debian Base
container_format: bare
disk_format: diskdump
size: 474066944
status: available
7h1rd-1m4g3-1d Debian Base Gama
container_format: bare
disk_format: diskdump
size: 474066944
status: available
[kamaki]: image list --owner=s0m3-u53r-1d
7h1rd-1m4g3-1d Debian Base Gama
container_format: bare
disk_format: diskdump
size: 474066944
status: available
[kamaki]:
Note
To get the current user id, use user authenticate in kamaki
An image can be unregistered by its image id, but only if the current user is also the image owner. In this example, there is only one image owned by current user.
Unregister image owned by current user
[kamaki]: image unregister 7h1rd-1m4g3-1d
[kamaki]:
Check if the image is deleted
[kamaki]: image list --owner=s0m3-u53r-1d
[kamaki]:
Attempt to unregister an image of another user
[kamaki]: image unregister f1r57-1m4g3-1d
(403) FORBIDDEN forbidden ()
[kamaki]:
The image will be registered again, but with some custom properties:
OS: Linux
user: someuser
These properties can be added freely by the user, and they are not required by the image server, but they can be used by many applications.
Attempt to register an image with custom properties
[kamaki]: image register 'Debian Base Gama' pithos:debian_base3.diskdump -p OS=Linux -p user=someuser
Metadata file pithos:debian_base3.diskdump.meta already exists
[kamaki]:
It’s true that a metafile with this name is already there, but we can override it (-f)
[kamaki]: image register -f 'Debian Base Gama' pithos:debian_base3.diskdump -p OS=Linux -p user=someuser
[kamaki]:
Download the meta file of the image (it was uploaded recently)
[kamaki]: file download pithos:debian_base3.diskdump.meta
Downloading pithos:debian_base3.diskdump.meta --> /home/someuser/debian_base3.diskdump.meta
Done
[kamaki]:
The metadata file can be edited. Let’s edit the file to add these properties:
OS: Linux
user: root
The resulting file will look like this:
{
"status": "available",
"name": "Debian Base Gama",
"checksum": "3cb03556ec971f...e8dd6190443b560cb7",
"id": "7h1rd-1m4g3-1d2",
"updated-at": "2013-06-19 08:01:00",
"created-at": "2013-06-19 08:00:22",
"properties": {
"OS": "Linux",
"USER": "root"
},
"location": "pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump",
"is-public": "False",
"owner": "s0m3-u53r-1d",
"disk-format": "diskdump",
"size": "903471104",
"deleted-at": "",
"container-format": "bare"
}
Warning
make sure the file is in a valid json format, otherwise image register will fail
In the following registration, a different name will be used for the image.
Register the image (don’t forget the -f parameter, to override the metafile).
[kamaki]: image register -f 'Debian Base Delta' pithos:debian_base3.diskdump --metafile=debian_base3.diskdump.meta
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: 7h1rd-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump
name: Debian Base Delta
owner: s0m3-u53r-1d
properties:
OS: Linux
USER: root
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
Metadata file uploaded as pithos:debian_base3.diskdump.meta (version 1359)
[kamaki]:
Image metadata and custom properties can be modified even after the image is registered. Metadata are fixed image attributes, like name, disk format etc. while custom properties are set by the image owner and, usually, refer to attributes of the images OS.
Let’s rename the image:
[kamaki]: image meta set 7h1rd-1m4g3-1d --name='Changed Name'
[kamaki]:
A look at the image metadata reveals that the name is changed:
[kamaki]: image info 7h1rd-1m4g3-1d
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: 7h1rd-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump
name: Changed Name
owner: s0m3-u53r-1d
properties:
OS: Linux
USER: root
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
[kamaki]:
We can use the same idea to change the values of other metadata like disk format, container format or status. On the other hand, we cannot modify the id, owner, location, checksum and dates. e.g., to publish and unpublish:
[kamaki]: image meta set 7h1rd-1m4g3-1d --publish --name='Debian Base Gama'
[kamaki]: image meta set 7h1rd-1m4g3-1d --unpublish
[kamaki]:
The first call publishes the image (set is-public to True) and also restores the name to “Debian Base Gama”. The second one unpublishes the image (set is-public to False).
To delete metadata, use the image meta delete method. For example, the following will set the value of status to an empty string:
[kamaki]: image meta delete 7h1rd-1m4g3-1d status
[kamaki]:
These operations can be used for properties with the same semantics:
[kamaki]: image meta set 7h1rd-1m4g3-1d -p user=user
[kamaki]: image info 7h1rd-1m4g3-1d
...
properties:
OS: Linux
USER: user
...
[kamaki]:
Just to test the feature, let’s create a property “greet” with value “hi there”, and then remove it. Also, let’s restore the value of USER:
[kamaki]: image meta set 7h1rd-1m4g3-1d -p greet='Hi there' -p user=root
[kamaki]: image info 7h1rd-1m4g3-1d
...
properties:
OS: Linux
USER: root
GREET: Hi there
...
[kamaki]: image meta delete 7h1rd-1m4g3-1d -p greet
[kamaki]: image info 7h1rd-1m4g3-1d
...
properties:
OS: Linux
USER: root
...
[kamaki]:
Let’s review the examples presented above:
- Register an image with name `Debian Base Gama`
- Unregister the image
- Register a new image of the uploaded image object, with custom properties
- Reregister the image with a meta file and modified properties and name
The image id is related to the image object
Although the image was unregistered and reregistered, the image id, that is produced automatically at the server side, was the same. This is due to the fact that image ids are 1 to 1 related to image objects uploaded to Pithos+
An explicit image name overrides the metafile
Each image needs a name and this is given as the first argument of the register command. This name overrides the name in the metafile.
Reregistration is not an update, but an override
The property user: root won over user: someuser, because it was set last. Actually, all properties were replaced by the new ones, when the image was reregistered, and the same holds with all customizable attributes of the image.
Let’s compine the metafile with a command line attribute user: admin
[kamaki]: image register -f 'Debian Base Delta' pithos:debian_base3.diskdump --metafile=debian_base3.diskdump.meta
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: 7h1rd-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump
name: Debian Base Delta
owner: s0m3-u53r-1d
properties:
OS: Linux
USER: root
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
Metadata file uploaded as pithos:debian_base3.diskdump.meta (version 1377)
[kamaki]:
Although the property OS was read from the metafile, the property USER was set by the command line property to admin.
Note
This feature allows the use of a metafile as a template for uploading multiple images with many common attributes but slight modifications per image
Warning
Make sure your container is set to auto, otherwise, there will be no object versions
[kamaki]: file versioning get pithos
x-container-policy-versioning: auto
[kamaki]:
To set versioning to auto
[kamaki]: file versioning set auto pithos
[kamaki]:
In the above examples, the image was registered many times by overriding the metafile. It is possible to avoid writing a metafile, as well as accessing older versions of the file.
Register the image without uploading a metafile
[kamaki]: image register 'Debian Base Delta' pithos:debian_base3.diskdump --metafile=debian_base3.diskdump.meta --no-metafile-upload
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: 7h1rd-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump
name: Debian Base Delta
owner: s0m3-u53r-1d
properties:
OS: Linux
USER: root
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
[kamaki]:
Uploaded metafiles are kept in versions, thanks to Pithos+ versioning support
[kamaki]: file versions pithos:debian_base3.diskdump.meta
1352
created: 19-06-2013 11:00:22
1359
created: 19-06-2013 11:01:00
1377
created: 19-06-2013 11:34:37
[kamaki]:
Consult the first version of the metafile
[kamaki]: file cat --object-version=1352 pithos:debian_base3.diskdump.meta
{
"status": "available",
"name": "Debian Base Gama",
"checksum": "3cb03556ec971f...e8dd6190443b560cb7",
"id": "7h1rd-1m4g3-1d2",
"updated-at": "2013-06-19 08:01:00",
"created-at": "2013-06-19 08:00:22",
"properties": {},
"location": "pithos://s0m3-u53r-1d/pithos/debian_base3.diskdump",
"is-public": "False",
"owner": "s0m3-u53r-1d",
"disk-format": "diskdump",
"size": "903471104",
"deleted-at": "",
"container-format": "bare"
}
[kamaki]:
Download the second version
[kamaki]: file download --object-version=1359 pithos:debian_base3.diskdump.meta debian_base3.diskdump.meta.v1359
Downloading pithos:debian_base3.diskdump.meta --> /home/someuser/debian_base3.diskdump.meta.v1359
Done
[kamaki]:
Let a directory at /home/someuser/images with a variety of images needed to be uploaded and registered.
Batch-upload the images
[kamaki]: file upload -R images pithos
mkdir pithos:images
Uploading /home/someuser/images/debian.diskdump --> pithos:images/debian.diskdump
Uploading /home/someuser/images/win8.diskdump --> pithos:images/win8.diskdump
...
Done
[kamaki]:
Make sure the images are uploaded to pithos:images/ remote directory object
[kamaki]: file list pithos:images/
D images/
983MB images/debian.diskdump
2.2GB images/win8.diskdump
...
[kamaki]:
Use the host shell capabilities to streamline the registration, so exit kamaki
[kamaki]: /exit
The following is a bash script that attempts to register the already uploaded images:
#!/bin/bash
userid=... # e.g., s0m3-u53r-1d
container=... # e.g., pithos
for path in images/*.diskdump; do
location=$container:${path}
kamaki image register $path $location
done
Let’s use the script (enriched with a separator message) to batch-register the images (all images will be named after their relative paths).
Also, let the registered images be public (accessible to all users for creating VMs) by adding the - - public flag argument when calling image register.
$ for path in images/*.diskdump; do
location=pithos:${path}
echo "- - - Register ${path} - - -"
kamaki image register $path $location --public
done
- - - Register images/debian.diskdump ---
checksum: 3cb03556ec971f...e8dd6190443b560cb7
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: d3b14n-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/images/debian.diskdump
name: images/debian.diskdump
owner: s0m3-u53r-1d
properties:
size: 903471104
status: available
updated-at: 2013-06-19 08:01:00
Metadata file uploaded as pithos:images/debian.diskdump.meta (version 4201)
- - - Register images/win8.diskdump ---
checksum: 4cb03556ec971f...e8dd6190443b560cb6
container-format: bare
created-at: 2013-06-19 08:00:22
deleted-at:
disk-format: diskdump
id: w1nd0w5-1m4g3-1d
is-public: False
location: pithos://s0m3-u53r-1d/pithos/images/win8.diskdump
name: images/win8.diskdump
owner: s0m3-u53r-1d
properties:
size: 2103471104
status: available
updated-at: 2013-06-19 08:01:00
Metadata file uploaded as pithos:images/debian.diskdump.meta (version 4301)
...
$
Note
All images can be re-registered, either individually or with a batch process.