[ovirt-users] Add multiple files to a VM via cloud-init
Juan Hernandez
jhernand at redhat.com
Fri Oct 31 23:00:08 UTC 2014
On 10/31/2014 06:47 PM, Branimir Pejakovic wrote:
>
>
>
> On Thu, Oct 30, 2014 at 12:52 PM, Branimir Pejakovic
> <branimirp at gmail.com <mailto:branimirp at gmail.com>> wrote:
>
>
>
> On Thu, Oct 30, 2014 at 12:39 PM, Shahar Havivi <shaharh at redhat.com
> <mailto:shaharh at redhat.com>> wrote:
>
> On 30.10.14 12:30, Branimir Pejakovic wrote:
> > On Thu, Oct 30, 2014 at 12:02 PM, Shahar Havivi
> <shaharh at redhat.com <mailto:shaharh at redhat.com>> wrote:
> >
> > > On 30.10.14 10:06, Branimir Pejakovic wrote:
> > > > On Thu, Oct 30, 2014 at 7:22 AM, Shahar Havivi
> <shaharh at redhat.com <mailto:shaharh at redhat.com>>
> > > wrote:
> > > >
> > > > > On 29.10.14 17:35, Branimir Pejakovic wrote:
> > > > > > Hi list,
> > > > > >
> > > > > > I was wondering is there a way to add multiple files
> to a vm via
> > > > > cloud-init
> > > > > > using python SDK. I was able to add /etc/resolv.conf and
> > > additionally I
> > > > > > would like to add config files for NICs (ifcfg-ethX)
> with appropriate
> > > > > > values (ip,gw,netmask). I used an example given here:
> > > > > > http://www.ovirt.org/Features/Cloud-Init_Integration . But
> > > > > unfortunately I
> > > > > > cannot do the same thing If I want to write multiple
> files to a vm in
> > > > > > params.Action class.
> > > > > >
> > > > > > Thank you in advance!
> > > > > you can use the custom script text box in oVirts
> cloud-init section,
> > > > > there you can add any cloud-init section - adding files
> examples can be
> > > > > found
> > > > > here:
> > > > >
> > > > >
> > >
> http://cloudinit.readthedocs.org/en/latest/topics/examples.html#writing-out-arbitrary-files
> > > > >
> > > > > Shahar Havivi.
> > > > >
> > > > >
> > > > Hi Shahar,
> > > >
> > > > Thank you for the reply.
> > > >
> > > > To be honest I knew for those scripts but I want to do it
> in automate
> > > > fashion just like in that example that I put in my
> original message. I
> > > have
> > > > tried to specify in params.Files class multiple files:
> > > >
> > > > vm_file1 = params.Files(file=[params.File(name = 'file1',
> content =
> > > > file1_content, type_= 'PLAINTEXT')])
> > > > vm_file2 = params.Files(file=[params.File(name = 'file2',
> content =
> > > > file2_content, type_= 'PLAINTEXT')])
> > > >
> > > > and then give them as arguments to params.CloudInit _init_
> constructor
> > > > (files=...) just like in that example above but it seems
> that I am doing
> > > > something wrong because it does not write multiple files -
> it writes only
> > > > when you specify one file all right. The exception is
> "Error: 'list'
> > > object
> > > > has no attribute 'export'" (I tried to specify those files
> as a list -
> > > > files=[vm_file1,vm_file2]).
> > > >
> > > > Thanks for any help.
> > > The custom script is currently the only option to add files
> via Cloud-Init
> > >
> > > Thanks,
> > > Shahar Havivi.
> > >
> > >
> > Hi Shahar,
> >
> > Granted. But the example in python
> > http://www.ovirt.org/Features/Cloud-Init_Integration uses
> custom script :)
> > I just want to know how to do the same thing in case when I
> want to write
> > more than one file to a VM - and yes - all those multiple
> files that I
> > want to write are specified via custom scripts.
> >
> > From the link - (The "Python SDK" paragraph: scontent object
> holds the
> > custom script):
> >
> > scontent = "write_files:\n- content: |\n search
> > example.com <http://example.com>\n nameserver
> 10.10.10.1\n nameserver
> > 10.10.10.2\n path: /etc/resolv.conf"
> >
> > For example (and just for example), I want to write to
> /etc/issue and
> > /etc/hosts not only /etc/resolv.conf. In essence, when vm goes
> to run-once
> > mode I want to write more than one file to a vm via Python (using
> > CloudInit) in automated fashion (and not touching oVirt GUI at
> all).
> You don't need to use the GUI,
> the sdks initialization have custom_script as string which is
> equivalent to
> the text box that you see in the GUI, and you can put the same
> content there
> (ie multiple files).
> Is that sufficient enough?
>
>
> Hi Shahar,
>
> Thanks! I will try this one. I was not aware of this feature.
> Although I can see that it was mentioned on the list (my bad).
>
> Thank you for your effort! I really do appreciate it!
>
>
>
> Hi,
>
> Please if somebody can help me because I am pretty stuck. As I said in
> previous posts I used this Python example
> http://www.ovirt.org/Features/Cloud-Init_Integration to set root
> password, hostname and resolv.conf. It worked without any problems for
> 3.4 oVirt version and equivalent Python SDK
> (ovirt-engine-sdk-python-3.4.x.noarch).
>
> Then, I have tried to write through yuml scripts more conf files than
> just resolv.conf to configure guest. I also saw this post on the list:
> http://lists.ovirt.org/pipermail/users/2014-October/028539.html. So
> based on that, I decided to upgraded oVirt and SDK
> (ovirt-engine-sdk-python-3.5.0.7-1.el6.noarch) to 3.5 version. The
> upgrade itself passed without any problem.
>
> From that point forward I tried to use custom_script parameter (as
> suggested by Shahar) inside Initialization class and CloudInit class
> without any luck.
>
> Can somebody please provide a simple Python code to submit yaml script
> to cloud-init?
>
> Also after the upgrade the example script I mentioned above can only
> change hostname. It does not write resolv.conf anymore nor it sets root
> password. I don't know if something is changed inside methods? For
> example, customization of virtual machine (memory,cpu,high availability,
> pinning to a certain host etc works without any problems).
>
> Thank you!
>
> Best regards,
>
> Branimir
>
The "custom_script" element doesn't work in combination with cloud-init
and run once. To make it work you have to use cloud-init and a file
element containing your custom script. Here you have an example:
#!/usr/bin/python
import base64
import re
from ovirtsdk.api import API
from ovirtsdk.xml import params
# A simple function to encode using base64 and now new lines:
def encode(s):
return re.sub("\s+", "", base64.encodestring(s))
# Connect to the server:
api = API(
url="https://engine35.example.com/ovirt-engine/api",
username="admin at internal",
password="redhat123",
insecure=True,
debug=True
)
# Find the virtual machine:
myvm = api.vms.get(name="myvm")
# Prepare the cloud-init custom script to write files:
myscript = """\
write_files:
"""
# Append one file:
myscript += """\
- encoding: b64
content: %s
owner: root:root
path: /etc/firstfile.txt
permissions: '0644'
""" % encode("The content of the first file")
# Append another file:
myscript += """\
- encoding: b64
content: %s
owner: root:root
path: /etc/secondfile.txt
permissions: '0644'
""" % encode("The content of the second file")
# Prepare the action to trigger initialization using cloud-init:
action = params.Action(
vm=params.VM(
initialization=params.Initialization(
cloud_init=params.CloudInit(
files=params.Files(
file=[
params.File(
name="myscript",
type_="plaintext",
content=myscript
)
]
)
)
)
)
)
# Start the virtual machine:
myvm.start(action)
# Disconnect from the server:
api.disconnect()
Regarding the problem with the root password we have a bug in 3.5 that
makes this fail. See here:
https://bugzilla.redhat.com/1156155
The problem is that we are not passing the user name to cloud-init, and
as a result it is changing the default cloud-init user password, not the
root pssword. To workaround the issue you can edit the
"/etc/cloud/cloud.cfg" file of the VM and change the default user name:
system_info:
distro: ...
default_user:
name: root <-- Change this from "fedora" or "cloud-init" to root
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