[ovirt-users] Ovirt api function
Juan Hernandez
jhernand at redhat.com
Fri Aug 22 09:44:20 UTC 2014
On 08/22/2014 06:35 AM, Shanil S wrote:
> Hi,
>
> VM rebuild means...Rebuild the VM with the same existing
> configuration...just erase the Vdisk and install again (like Fresh
> install).
> We want to rebuild the VM with the same existing OS template...also it
> will be good if user can select other OS template also for the rebuild
> purpose...
> With CD_ISO it require the manual installation...we don't want the
> manual installation...we looking for a way to rebuild the VM with OS
> templates....
> Is there any API method to achieve this ??
>
The usual process to do this is the following:
1. Manually, using the GUI, you create a VM and install the OS.
2. Manually seal the VM for use as a template. The idea is to remove
from the VM any configuration that may create a conflict when multiple
VMs are created from the template. There are different ways to do this,
depending on the OS that you are using. Here you can find some
documentation:
https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Virtualization/3.4/html/Administration_Guide/sect-Sealing_Templates_in_Preparation_for_Deployment.html
3. Manually shut it down and create a template from it.
4. Manually remove the VM (you can keep it, but it isn't needed).
All these steps are usually done manually, as it isn't usually worth
automating them, but if you wish you can also do them with the API.
Once you have the template you can create multiple VMs from it, and for
this you will probably use the API. For example, assuming that you know
the ids of the cluster and the template:
#!/bin/sh -ex
url="https://ovirt.example.com/ovirt-engine/api"
user="admin at internal"
password="******"
curl \
--verbose \
--insecure \
--request POST \
--header "Accept: application/xml" \
--header "Content-Type: application/xml" \
--user "${user}:${password}" \
--data "
<vm>
<name>mynewvm</name>
<cluster id='5f840556-81de-427d-8d30-a06cdb15b7f9'/>
<template id='f9eb10b8-6f94-469f-a8a6-660c41b103d7'/>
</vm>
" \
"${url}/vms"
Or you may want to use the Python SDK:
#!/usr/bin/python
import ovirtsdk.api
import ovirtsdk.xml
api = ovirtsdk.api.API(
url="https://ovirt.example.com/ovirt-engine/api",
username="admin at internal",
password="******",
insecure=True
)
cluster =
ovirtsdk.xml.params.Cluster(id="5f840556-81de-427d-8d30-a06cdb15b7f9")
template =
ovirtsdk.xml.params.Template(id="f9eb10b8-6f94-469f-a8a6-660c41b103d7")
vm = ovirtsdk.xml.params.VM()
vm.set_name("mynewvm")
vm.set_cluster(cluster)
vm.set_template(template)
api.vms.add(vm)
api.disconnect()
There is also a Java SDK, if you prefer it.
In this scenario you will usually want to change the host name or other
properties of the new VM. That you can do with cloud-init (for Linux) or
Sysprep (for Windows). That can also be automated with the api.
> Regarding the statitics report, is there any API method to fetch the
> monthly and weekly usages report ?, we are planning to create a usage
> chart by using these values.
>
The RESTAPI doesn't provide this kind of accumulated statistics. I'd
suggest to explore the oVirt reports DWH and reports applications:
http://www.ovirt.org/Ovirt_DWH
http://www.ovirt.org/Ovirt_Reports
> --
> Regards
> Shanil
>
>
> On Fri, Aug 22, 2014 at 9:46 AM, OvirtAndKvm <oVirt at goproject.info
> <mailto:oVirt at goproject.info>> wrote:
>
> Do you mean like; attach a new OS install ISO CD to the VM, change
> the VM's boot order to CD first, reboot the VM and boot up on the CD
> and install the new OS, selecting to reformat over the old installed
> OS ?
>
> or am I miss understanding your question ?
>
>
>
> At Friday, 22-08-2014 on 13:58 Shanil S wrote:
>
> Hi Juan,
>
> Thanks for your replies..
>
> Regarding the rebuild VM, Is that any method to reinstall the os
> on the VM without remove it or create a new one?
>
>
> --
> Regards
> Shanil
>
>
> On Thu, Aug 21, 2014 at 4:55 PM, Juan Hernandez
> <jhernand at redhat.com <mailto:jhernand at redhat.com>> wrote:
>
> On 08/20/2014 12:42 PM, Shanil S wrote:
> > Hi,
> >
> >
> > I would like to create the following functions using the
> ovirt api
> >
> > 1. Rebuild VM
>
> What do you exactly mean by "rebuild vm"?
>
> > 2. Restore the screenthots of one vm to another vm
>
> What you can do is create a new VM from an existing
> snapshot, something
> like this:
>
> #!/bin/sh -ex
>
> url="https://ovirt.example.com/ovirt-engine/api"
> user="admin at internal"
> password="******"
>
> curl \
> --verbose \
> --insecure \
> --request POST \
> --header "Accept: application/xml" \
> --header "Content-Type: application/xml" \
> --user "${user}:${password}" \
> --data "
> <vm>
> <name>myclone</name>
> <cluster id='00000001-0001-0001-0001-000000000171'/>
> <snapshots>
> <snapshot id='f09a98fd-2c7e-40eb-a9ae-6b7f86412bb0'/>
> </snapshots>
> </vm>
> " \
> "${url}/vms"
>
> You need to modify that script with your URL, user name,
> password,
> cluster and snapshot id.
>
> > 3. Display cpu,network etc usages
> >
>
> The statistics are available in the "statistics"
> sub-resource. For
> example, if you want to get the statistics of a host you can
> do the
> following:
>
> #!/bin/sh -ex
>
> url="https://ovirt.example.com/ovirt-engine/api"
> user="admin at internal"
> password="******"
>
> curl \
> --verbose \
> --insecure \
> --request GET \
> --header "Accept: application/xml" \
> --user "${user}:${password}" \
> "${url}/hosts/40cc4c33-2560-4516-b028-1d59638139c3/statistics"
>
> There you will find different statistics, like "memory.total",
> "memory.used", etc. Take a look. Once you know what
> statistic you want
> you can get its details like this:
>
> curl \
> --verbose \
> --insecure \
> --request GET \
> --header "Accept: application/xml" \
> --user "${user}:${password}" \
> "${url}/hosts/40cc4c33-2560-4516-b028-1d59638139c3/statistics/7816602b-c05c-3db7-a4da-3769f7ad8896"
>
> This can be cumbersome to do with a shell script, so you may
> want to use
> the Python or Java SDKs, or just use directly the ovirt-shell:
>
> $ ovirt-shell --insecure
> URL: https://ovirt.example.com/ovirt-engine/api
> Username: admin at internal
> Password: ******
> [oVirt shell (connected)]# show statistic memory.total
> --host-identifier
> myhost
> id : 7816602b-c05c-3db7-a4da-3769f7ad8896
> name : memory.total
> description : Total memory
> host-id : 40cc4c33-2560-4516-b028-1d59638139c3
> type : GAUGE
> unit : BYTES
> values-type : INTEGER
> values-value-datum: 2099249152
>
> > I couldn't find out any direct api method to do the above,
> Is it
> > possible to do these operations using api ? If anyone
> knows it please
> > help me to sort out it.
> >
> >
> >
> > --
> > Regards
> > Shanil
>
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