Re: Re: Cloud-init datasource ordering

[Kenn Leth Hansen <KLH@fullrate.dk>]

> On 4/3/19 08:29, Thomas Goirand wrote:
>> On 4/3/19 10:54 AM, Kenn Leth Hansen wrote:
>>> Hi list,
>>>
>>> I've discovered the CloudStack datasource causes cloud-init to wait for 120 seconds before continuing to the next datasource if no service is responding on port 80 on the DHCP server address. As I am using an Ec2-style metadata server, I need to wait 120 seconds every time i boot an instance until it is operational as this listens on "magic" IP 169.254.169.254 and I cannot easily redirect traffic to this IP.
>>>
>>> The CloudStack datasource seems to have been introduced in dc1abbe1 but I don't see any reasoning for the ordering. In commit ce65da02 CloudStack was moved down the list to fix similar symptoms with OpenStack.
>>>
>>> Would it be possible to move the Ec2 datasource up the list like "[ NoCloud, AltCloud, ConfigDrive, OpenStack, Ec2, CloudStack, ${DIGITAL_OCEAN_SOURCE} MAAS, OVF, GCE, None ]"? This also seems to be in line with expectations on how the datasources have been sorted before dc1abbe1.
>>>
>>> Regards,
>>> Kenn
>> If we do that, then OpenStack people are going to wait 120 seconds. So,
>> bad idea...
>>
>> Cheers,
>>
>> Thomas Goirand (zigo)
>
>I may be missing something, but why would that impact OpenStack
>privisioning?  They'd still be ahead of CloudStack in the proposed
>ordering.  I'd need to trawl through the code and verify, but wouldn't
>it be sensible to put CloudStack about as far down the line as possible,
>given the overall impact (unless other data sources are expensive?).
>
>To Kenn's comment though, in general with cloud-init you want to be
>giving it as specific a data source as you can.  If it's affecting you
>on every boot, I'd suggest putting the specific data source that is
>right for your environment in to /etc/cloud.cfg so that cloud-init jumps
>straight to that one instead of wasting time on anything else.
>
>Cloud-init upstream has tried to introduce ways to shortcut the process
>of figuring out "Where on earth am I" process. A number of the clouds
>put something suitable in the DMI data coming from the BIOS, and I know
>cloud-init is starting to use that as a big pointer.
>
>Paul

I'd really appreciate if we can find an order which suits the overall
community's use-cases.

I think my proposal is sane and prioritizes the most common use-cases.

But again, this is why I am posting on the list to get a nuanced discussion.

In the meantime I'll investigate if I can provide the appropriate DMI data
to cloud-init for selection of the Ec2 datasource.

Thanks.

/Kenn