[one-users] Reference CONTEXT variables within CONTEXT
Valentin Bud
valentin.bud at gmail.com
Sat May 18 02:05:25 PDT 2013
Hello Carlos,
I would gladly open a request if you and others from the community think
this is useful.
I see this topic as a Request For Comments :-).
For me the NAME of the VM would prove useful to be available within
CONTEXT. The NAME being the `onetemplate instantiate 8 --name NAME`
This way I could have the following template which the users could use:
CONTEXT=[
CONTEXT_FILES_LOCATION="$CONTEXT_FILES_LOCATION",
DOMAIN="$DOMAIN",
FILES="$CONTEXT_FILES_LOCATION/$FQDN/ssh_host_rsa_key
$CONTEXT_FILES_LOCATION/$FQDN/ssh_host_rsa_key.pub",
FQDN="$HOSTNAME.$DOMAIN.",
HOSTNAME="$HOSTNAME" ]
CONTEXT_FILES_LOCATION="/var/lib/cloud/context"
CPU="1"
DISK=[
IMAGE="debian6-stable" ]
DISK=[
IMAGE="vdb.$HOSTNAME.$DOMAIN" ]
DOMAIN="domain.tld"
GRAPHICS=[
LISTEN="0.0.0.0",
TYPE="vnc" ]
** HOSTNAME="$NAME" **
MEMORY="2048"
NIC=[
NETWORK="dev.domain.tld" ]
OS=[
ARCH="x86_64" ]
VCPU="4"
>From Sunstone, at instantiation time you are asked to give the VM a name.
That NAME could be used in the template also. Maybe NAME is not the proper
way for this variable.
The above applies to my use case. In my case each project I run on top of
OpenNebula is a (sub)domain.
The above would ease the process of instantiating a new VM. Maybe I could
even use a hook to create the second image on the fly at CREATE time,
though I think OpenNebula would complain that the disk is missing. Haven't
tested this yet.
Thoughts? Thanks.
Cheers and Goodwill,
On Fri, May 17, 2013 at 4:47 PM, Carlos Martín Sánchez <
cmartin at opennebula.org> wrote:
> Hi,
>
> I'm glad you found a way to make it work.
>
> If it is really needed, we could add support to reference other context
> attributes. Please open a request If you still think it would be better.
>
> Cheers,
> Carlos
>
> --
> Join us at OpenNebulaConf2013 <http://opennebulaconf.com> in Berlin,
> 24-26 September, 2013
> --
> Carlos Martín, MSc
> Project Engineer
> OpenNebula - The Open-source Solution for Data Center Virtualization
> www.OpenNebula.org | cmartin at opennebula.org | @OpenNebula<http://twitter.com/opennebula><cmartin at opennebula.org>
>
>
> On Thu, May 16, 2013 at 2:14 PM, Valentin Bud <valentin.bud at gmail.com>wrote:
>
>> Hello Community,
>>
>> First of all, I apologise I forgot to say hi in my previous E-Mail :|.
>>
>> On Thu, May 16, 2013 at 10:28:14AM +0300, Valentin Bud wrote:
>> > I am trying to reference the CONTEXT variables from within CONTEXT.
>> >
>> > For example, I define the DOMAIN="domain.tld" and the HOSTNAME="host".
>> > I would like to have a variable FQDN="$HOST.$DOMAIN.".
>> >
>> > I have tried to achieve the above using the following in CONTEXT section
>> > of the template.
>> >
>> > Case I
>> > --
>> >
>> > $ onetemplate show vars
>> >
>> > TEMPLATE CONTENTS
>> > CONTEXT=[
>> > DOMAIN="domain.tld",
>> > FQDN="$DOMAIN.$HOSTNAME.",
>> > HOSTNAME="host" ]
>> >
>> > [... output omitted for brevity ...]
>> >
>> > Instantiating the template results in the following variables added to
>> > the VM.
>> >
>> > $ onevm show vars
>> >
>> > VIRTUAL MACHINE TEMPLATE
>> > CONTEXT=[
>> > DISK_ID="1",
>> > DOMAIN="domain.tld",
>> > *FQDN="..",*
>> > HOSTNAME="host",
>> > TARGET="hda" ]
>> >
>> > Case II
>> > --
>> >
>> > $ onetemplate show vars
>> >
>> > CONTEXT=[
>> > DOMAIN="domain.tld",
>> > FQDN="$CONTEXT[$DOMAIN].$CONTEXT[$HOSTNAME].",
>> > HOSTNAME="host" ]
>> > [... output omitted for brevity ...]
>> >
>> > Same result in the VM.
>> >
>> > $ onevm show vars
>> >
>> > VIRTUAL MACHINE TEMPLATE
>> > CONTEXT=[
>> > DISK_ID="1",
>> > DOMAIN="domain.tld",
>> > *FQDN=".."*,
>> > HOSTNAME="host",
>> > TARGET="hda" ]
>> > [... output omitted for brevity ...]
>> >
>> > Is it possible to achieve what am I trying or should I search for a new
>> > solution?
>> >
>> > I have a simple use case. I am generating, via a hook, the ssh keys for
>> > the VM in question. At boot I copy the keys from /mnt to /etc/ssh via
>> > a crafted one-context script. Awesome mechanism by the way :-).
>> >
>> > I am generating the keys in
>> > CONTEXT_FILES_LOCATION=/var/lib/cloud/context/host.domain.tld.
>> >
>> > I would like to use the following in the CONTEXT section:
>> >
>> > CONTEXT=[
>> > CONTEXT_FILES_LOCATION=/var/lib/cloud/context/host.domain.tld./,
>> > DOMAIN="domain.tld",
>> > FILES="$CONTEXT_FILES_LOCATION/$FQDN/ssh_host_rsa_key ...",
>> > HOSTNAME="host",
>> > FQDN="$HOSTNAME.$DOMAIN." ]
>> >
>> > This makes the template much more dynamic. I would just change the
>> HOSTNAME
>> > and the paths would get generated dynamically.
>> >
>>
>> Writing the HOSTNAME, DOMAIN, CONTEXT_FILES_LOCATION outside the CONTEXT
>> section and referencing them from within CONTEXT works :-).
>>
>> Example
>> --
>>
>> $ onetemplate show vars
>>
>> TEMPLATE CONTENTS
>> CONTEXT=[
>> CONTEXT_FILES_LOCATION="$CONTEXT_FILES_LOCATION",
>> DOMAIN="$DOMAIN",
>> FILES="$CONTEXT_FILES_LOCATION/$FQDN/ssh_host_rsa_key
>> $CONTEXT_FILES_LOCATION/$FQDN/ssh_host_rsa_key.pub",
>> FQDN="$HOSTNAME.$DOMAIN.",
>> HOSTNAME="$HOSTNAME" ]
>> CONTEXT_FILES_LOCATION="/var/lib/cloud/context"
>> CPU="1"
>> DISK=[
>> IMAGE="vars" ]
>> DOMAIN="domain.tld"
>> GRAPHICS=[
>> LISTEN="0.0.0.0",
>> TYPE="vnc" ]
>> HOSTNAME="host"
>> MEMORY="2048"
>> NIC=[
>> NETWORK="host.domain.tld" ]
>> OS=[
>> ARCH="x86_64" ]
>> VCPU="4"
>>
>> After instantiating the machine I have the desired results.
>>
>> $ onevm show vars
>>
>> VIRTUAL MACHINE TEMPLATE
>> CONTEXT=[
>> CONTEXT_FILES_LOCATION="/var/lib/cloud/context",
>> DISK_ID="1",
>> DOMAIN="dev.corview.de",
>> FILES="/var/lib/cloud/context//ssh_host_rsa_key
>> /var/lib/cloud/context//ssh_host_rsa_key.pub",
>> FQDN="vars.domain.tld.",
>> HOSTNAME="vars",
>> TARGET="hda" ]
>>
>> Now I can easily generate SSH host keys for each machine if this wasn't
>> done already in a previous VM instantation.
>>
>> Thanks and sorry for the noise. If this is mentioned somewhere in the
>> docs, my bad.
>>
>> Cheers and Goodwill,
>>
>> --
>> Valentin Bud
>> http://databus.pro/ | valentin at databus.pro
>> _______________________________________________
>> Users mailing list
>> Users at lists.opennebula.org
>> http://lists.opennebula.org/listinfo.cgi/users-opennebula.org
>>
>
>
--
Valentin Bud
http://databus.pro | valentin at databus.pro
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