^^^^^
snf-image-creator comes in 2 variants:
+
* snf-image-creator: A non-interactive command line program
* snf-mkimage: A user-friendly dialog-based program
+Both expect the input media as first argument. The input media may be a local
+file, a block device or *"/"* if you want to create an image out of the running
+system (see `host bundling operation`_).
+
Non-interactive version
=======================
.. code-block:: console
- $ snf-image-creator --help
-
- Usage: snf-image-creator [options] <input_media>
-
- Options:
- --version show program's version number and exit
- -h, --help show this help message and exit
- -o FILE, --outfile=FILE
- dump image to FILE
- -f, --force overwrite output files if they exist
- -s, --silent silent mode, only output errors
- -u FILENAME, --upload=FILENAME
- upload the image to pithos with name FILENAME
- -r IMAGENAME, --register=IMAGENAME
- register the image with ~okeanos as IMAGENAME
- -a ACCOUNT, --account=ACCOUNT
- Use this ACCOUNT when uploading/registering images
- [Default: None]
- -m KEY=VALUE, --metadata=KEY=VALUE
- Add custom KEY=VALUE metadata to the image
- -t TOKEN, --token=TOKEN
- Use this token when uploading/registering images
- [Default: None]
- --print-sysprep print the enabled and disabled system preparation
- operations for this input media
- --enable-sysprep=SYSPREP
- run SYSPREP operation on the input media
- --disable-sysprep=SYSPREP
- prevent SYSPREP operation from running on the input
- media
- --no-sysprep don't perform system preparation
- --no-shrink don't shrink any partition
-
-
-Most input options are self-describing. If you want to save a local copy for
-the image you create, you specify *-o* option. To upload the image to
-*pithos+*, you specify valid credentials with *-a* and *-t* options and a
-filename using *-u*. If you want to register the image with *~okeanos*,
-in addition to *-u* specify a registration name using *-r*.
-
-By default snf-image-creator will perform a number of system preparation
-operations on the snapshot of the media and will shrink the last partition
-found, before extracting the image. Both can be disabled by specifying
+ $ snf-image-creator --help
+ Usage: snf-image-creator [options] <input_media>
+
+ Options:
+ --version show program's version number and exit
+ -h, --help show this help message and exit
+ -o FILE, --outfile=FILE
+ dump image to FILE
+ -f, --force overwrite output files if they exist
+ -s, --silent output only errors
+ -u FILENAME, --upload=FILENAME
+ upload the image to the storage service with name FILENAME
+ -r IMAGENAME, --register=IMAGENAME
+ register the image with the compute service as IMAGENAME
+ -m KEY=VALUE, --metadata=KEY=VALUE
+ add custom KEY=VALUE metadata to the image
+ -t TOKEN, --token=TOKEN
+ use this authentication token when
+ uploading/registering images
+ -a URL, --authentication-url=URL
+ use this authentication URL when uploading/registering
+ images
+ -c CLOUD, --cloud=CLOUD
+ use this saved cloud account to authenticate against a
+ cloud when uploading/registering images
+ --print-sysprep print the enabled and disabled system preparation
+ operations for this input media
+ --enable-sysprep=SYSPREP
+ run SYSPREP operation on the input media
+ --disable-sysprep=SYSPREP
+ prevent SYSPREP operation from running on the input
+ media
+ --no-sysprep don't perform any system preparation operation
+ --no-shrink don't shrink any partition
+ --public register image with the compute service as public
+ --tmpdir=DIR create large temporary image files under DIR
+
+Most input options are self-describing. If you want to save a local copy of
+the image you create, provide a filename using the *-o* option. To upload the
+image to the storage service of a cloud, provide valid cloud API access info
+(by either using a token and a URL with *-t* and *-a* respectively, or a cloud
+name with *-c*) and a remote filename using *-u*. If you also want to register
+the image with the compute service of the cloud, in addition to *-u* provide a
+registration name using *-r*. All images are
+registered as *private*. Only the user that registers the image can create
+VM's out of it. If you want the image to be visible by other user too, use the
+*--public* option.
+
+By default, before extracting the image, snf-image-creator will perform a
+number of system preparation operations on the snapshot of the media and will
+shrink the last partition found. Both actions can be disabled by specifying
*--no-sysprep* and *--no-shrink* respectively.
-If *--print-sysprep* is defined, the program will exit after outputing a
-list of enabled and disabled system preparation operation appliable to this
-media source. The user can enable or disable specific *syspreps* when creating
-an image, using *-{enable,disable}-sysprep* options. You can specify those
-options multiple times to enable or disable multiple *syspreps*.
+If *--print-sysprep* is defined, the program will exit after printing a
+list of enabled and disabled system preparation operation applicable to this
+input media. The user can enable or disable specific *syspreps*, using
+*-{enable,disable}-sysprep* options. The user may specify those options
+multiple times.
Running *snf-image-creator* with *--print-sysprep* on a raw file that hosts a
-debian system, we get the following output:
+debian system, we print the following output:
-.. code-block:: console
+.. _sysprep:
- $ snf-image-creator --print-sysprep debian_desktop.img
+.. code-block:: console
- snf-image-creator 0.1
+ $ snf-image-creator --print-sysprep ubuntu.raw
+ snf-image-creator 0.3
=====================
- Examining source media `debian_desktop.img'... looks like an image file
- Snapshotting media source... done
+ Examining source media `ubuntu_hd.raw' ... looks like an image file
+ Snapshotting media source ... done
Enabling recovery proc
- Launching helper VM... done
- Inspecting Operating System... found a(n) debian system
- Mounting the media read-only... done
-
+ Launching helper VM (may take a while) ... done
+ Inspecting Operating System ... ubuntu
+ Mounting the media read-only ... done
+ Collecting image metadata ... done
+ Umounting the media ... done
+
Enabled system preparation operations:
cleanup-cache:
- Remove all regular files under /var/cache
-
+ Remove all regular files under /var/cache
+
cleanup-log:
- Empty all files under /var/log
-
+ Empty all files under /var/log
+
cleanup-passwords:
- Remove all passwords and lock all user accounts
-
+ Remove all passwords and lock all user accounts
+
cleanup-tmp:
- Remove all files under /tmp and /var/tmp
-
+ Remove all files under /tmp and /var/tmp
+
cleanup-userdata:
- Delete sensitive userdata
-
+ Delete sensitive userdata
+
fix-acpid:
- Replace acpid powerdown action scripts to immediately shutdown the
- system without checking if a GUI is running.
-
+ Replace acpid powerdown action scripts to immediately shutdown the
+ system without checking if a GUI is running.
+
remove-persistent-net-rules:
- Remove udev rules that will keep network interface names persistent
- after hardware changes and reboots. Those rules will be created again
- the next time the image runs.
-
+ Remove udev rules that will keep network interface names persistent
+ after hardware changes and reboots. Those rules will be created again
+ the next time the image runs.
+
remove-swap-entry:
- Remove swap entry from /etc/fstab. If swap is the last partition
- then the partition will be removed when shrinking is performed. If the
- swap partition is not the last partition in the disk or if you are not
- going to shrink the image you should probably disable this.
-
+ Remove swap entry from /etc/fstab. If swap is the last partition
+ then the partition will be removed when shrinking is performed. If the
+ swap partition is not the last partition in the disk or if you are not
+ going to shrink the image you should probably disable this.
+
use-persistent-block-device-names:
- Scan fstab & grub configuration files and replace all non-persistent
- device references with UUIDs.
-
+ Scan fstab & grub configuration files and replace all non-persistent
+ device references with UUIDs.
+
Disabled system preparation operations:
cleanup-mail:
- Remove all files under /var/mail and /var/spool/mail
-
+ Remove all files under /var/mail and /var/spool/mail
+
remove-user-accounts:
- Remove all user accounts with id greater than 1000
+ Remove all user accounts with id greater than 1000
+
+
+ cleaning up ...
-
- cleaning up...
-
-If we want the image to have all normal user accounts and all mail files
-removed, we can create it specifying *--enable-sysprep* option like this:
+If you want the image to have all normal user accounts and all mail files
+removed, you should use *--enable-sysprep* option like this:
.. code-block:: console
.. code-block:: console
- $ Usage: snf-mkimage [options] [<input_media>]
+ $ snf-mkimage --help
+ Usage: snf-mkimage [options] [<input_media>]
- Options:
- --version show program's version number and exit
- -h, --help show this help message and exit
- -l FILE, --logfile=FILE
- log all messages to FILE
+ Options:
+ --version show program's version number and exit
+ -h, --help show this help message and exit
+ -l FILE, --logfile=FILE
+ log all messages to FILE
+ --tmpdir=DIR create large temporary image files under DIR
If the input media is not specified in the command line, in the first dialog
-box the user will be asked to specify it. After the input media is examined and
-the program is initialized, the user will be given the choice to run
-*snf-mkimage* in *wizard* or *expert* mode.
+box the user will be asked to specify it:
+
+.. image:: /snapshots/select_media.png
+
+The user can select a file (regular or block device) or use the *Bundle Host*
+button to create an image out of the running system (see
+`Host bundling operation`_).
+
+After the input media is examined and the program is initialized, the user will
+be given the choice to run *snf-mkimage* in *wizard* or *expert* mode.
Wizard mode
-----------
When *snf-mkimage* runs in *wizard* mode, the user is just asked to provide the
following basic information:
+ * Cloud: The cloud account to use to upload and register the resulting image
* Name: A short name for the image (ex. "Slackware")
- * Description: An one-line description for the image (ex. "Slackware Linux 14.0 with KDE")
- * Account: An *~okeanos* account email
- * Token: A token corresponding to the account defined previously
+ * Description: An one-line description for the image
+ (ex. "Slackware Linux 14.0 with KDE")
+ * Registration Type: Private or Public
-After confirming, the image will be extracted, uploaded to *pithos+* and
-registered to *~okeanos*. The user will also be given the choice to keep a local
-copy of it. For most users the functionality this mode provides should be
-sufficient.
+After confirming, the image will be extracted, uploaded to the storage service
+and registered with the compute service of the selected cloud. The user will
+also be given the choice to keep a local copy of it.
+
+For most users the functionality this mode provides should be sufficient.
Expert mode
-----------
Expert mode allows the user to have better control on the image creation
-process. In the picture below the main menu can be seen:
+process. The main menu can be seen in the picture below:
.. image:: /snapshots/main_menu.png
In the *Register* sub-menu the user can provide:
- * The credentials to login to *~okeanos*
- * A pithos filename for the uploaded *diskdump* image
- * A name for the image to be registered to *~okeanos* with
+ * Which cloud account to use
+ * A filename for the uploaded *diskdump* image
+ * A name for the image to use when registering it with the storage service of
+ the cloud, as well as the registration type (*private* or *public*)
-By choosing the *Extract* menu entry the user can dump the image to the local
-file system and finally, if the user selects *Reset*, the system will ignore
+By choosing the *Extract* menu entry, the user can dump the image to the local
+file system. Finally, if the user selects *Reset*, the system will ignore
all changes made so far and will start the image creation process again.
+
+Host bundling operation
+=======================
+
+As a new feature in *v0.2*, snf-image-creator can create images out of the host
+system that runs the program. This is done either by specifying / as input
+media or by using the *Bundle Host* button in the media selection dialog of
+snf-mkimage. During this operation, the files of the disk are copied into a
+temporary image file, which means that the file system that will host the
+temporary image needs to have a lot of free space (see `large temporary files`_
+for more information).
+
+Creating a new image
+====================
+
+Suppose you want to create a new Ubuntu server image. Download the installation
+disk from the Internet:
+
+.. code-block:: console
+
+ $ wget http://ubuntureleases.tsl.gr/12.04.2/ubuntu-12.04.2-server-amd64.iso
+
+Verify that it has been downloaded correctly:
+
+.. code-block:: console
+
+ $ echo 'a8c667e871f48f3a662f3fbf1c3ddb17 ubuntu-12.04.2-server-amd64.iso' > check.md5
+ $ md5sum -c check.md5
+
+Create a 2G sparse file to host the new system:
+
+.. code-block:: console
+
+ $ truncate -s 2G ubuntu.raw
+
+And install the Ubuntu system on this file:
+
+.. code-block:: console
+
+ $ sudo kvm -boot d -drive file=ubuntu.raw,format=raw,cache=none,if=virtio \
+ -m 1G -cdrom ubuntu-12.04.2-server-amd64.iso
+
+.. warning::
+
+ During the installation, you will be asked about the partition scheme. Don't
+ use LVM partitions. They are not supported by snf-image-creator.
+
+You will be able to boot your installed OS and make any changes you want
+(e.g. install openssh-server) using the following command::
+
+ $ sudo kvm -m 1G -boot c -drive file=ubuntu.raw,format=raw,cache=none,if=virtio
+
+After you're done, you may use *snf-mkimage* as root to create and upload the
+image:
+
+.. code-block:: console
+
+ $ sudo -s
+ $ snf-mkimage ubuntu.raw
+
+In the first screen you will be asked to choose if you want to run the program
+in *Wizard* or *Expert* mode. Choose *Wizard*.
+
+.. image:: /snapshots/wizard.png
+
+Then you will be asked to select a cloud and provide a name, a description and
+a registration type (*private* or *public*). Finally, you'll be asked to
+confirm the provided data.
+
+.. image:: /snapshots/confirm.png
+
+Choosing *YES* will create and upload the image to your cloud account.
+
+Limitations
+===========
+
+Supported operating systems
+---------------------------
+
+*snf-image-creator* can only fully function on input media hosting *Linux*
+systems. The program will detect the needed metadata and you may use it to
+upload and register other *Unix* or *Windows* images, but you cannot use it to
+shrink them or perform system preparation operations.
+
+Logical Volumes
+---------------
+
+The program cannot work on LVM partitions [#f1]_. The input media may only
+contain primary or logical partitions.
+
+Para-virtualized drivers
+------------------------
+
+Most synnefo deployments uses the *VirtIO* framework. The disk I/O controller
+and the Ethernet cards on the VM instances are para-virtualized and need
+special *VirtIO* drivers. Those drivers are included in the Linux Kernel
+mainline since version 2.6.25 and are shipped with all the popular Linux
+distributions. The problem is that if the driver for the para-virtualized disk
+I/O controller is built as module, it needs to be preloaded using an initial
+ramdisk, otherwise the VM won't be able to boot.
+
+Many popular Linux distributions, like Ubuntu and Debian, will automatically
+create a generic initial ramdisk file that contains many different modules,
+including the VirtIO drivers. Others that target more experienced users, like
+Slackware, won't do that [#f2]_. *snf-image-creator* cannot resolve this kind
+of problems and it's left to the user to do so. Please refer to your
+distribution's documentation for more information on this. You can always check
+if a system can boot with para-virtualized disk controller by launching it with
+kvm using the *if=virtio* option (see the kvm command in the
+`Creating a new image`_ section).
+
+Some caveats on image creation
+==============================
+
+Image partition schemes and shrinking
+-------------------------------------
+
+When image shrinking is enabled, *snf-image-creator* will shrink the last
+partition on the disk. If this is a swap partition, it will remove it, save
+enough information to recreate it during image deployment and shrink the
+partition that lays just before that. This will make the image smaller which
+speeds up the deployment process.
+
+During image deployment, the last partition is enlarged to occupy the available
+space in the VM's hard disk and a swap partition is added at the end if a SWAP
+image property is present.
+
+Keep this in mind when creating images. It's always better to have your swap
+partition placed as the last partition on the disk and have your largest
+partition (*/* or */home*) just before that.
+
+Large temporary files
+---------------------
+
+*snf-image-creator* may create large temporary files when running:
+
+ * During image shrinking, the input media snapshot file may reach the size of
+ the original media.
+ * When bundling the host system, the temporary image file may became as large
+ as the rest of the disk files altogether.
+
+*/tmp* directory is not a good place for hosting large files. In many systems
+the contents of */tmp* are stored in volatile memory and the size they may occupy
+is limited. By default, *snf-image-creator* will use a heuristic approach to
+determine where to store large temporary files. It will examine the free space
+under */var/tmp*, the user's home directory and */mnt* and will pick the one
+with the most available space. The user may overwrite this behaviour and
+indicate a different directory using the *tmpdir* option. This option is
+supported by both *snf-image-creator* and *snf-mkimage*.
+
+.. rubric:: Footnotes
+
+.. [#f1] http://sourceware.org/lvm2/
+.. [#f2] http://mirrors.slackware.com/slackware/slackware-14.0/README.initrd