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<p class="MsoNormal"><span style="color:#1F497D">It doesn’t, at least not according to my interpretation of the documentation in the Kea Administrator’s Guide, Section 14.4.4<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">I very specifically need to query an external service (*NOT* a database), and then generate a lease (or reservation) based on the information returned from that query.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">My conundrum is that I can call an external script, but because the DHCP server blocks waiting on the script to complete, I cannot update the lease information until the script exits.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">Thanks,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D">-T<o:p></o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif"">From:</span></b><span style="font-size:10.0pt;font-family:"Tahoma","sans-serif""> Kea-users [mailto:kea-users-bounces@lists.isc.org]
<b>On Behalf Of </b>Joseph Bernard<br>
<b>Sent:</b> Tuesday, August 14, 2018 7:34 PM<br>
<b>To:</b> kea-users@lists.isc.org<br>
<b>Subject:</b> Re: [Kea-users] Suggestions requested<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I believe the Host Commands Library premium hook does this. <o:p>
</o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Thanks,<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Joseph B.<o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt"><br>
On Aug 14, 2018, at 5:05 PM, Tom Gillman <<a href="mailto:Tom.Gillman@virtustream.com">Tom.Gillman@virtustream.com</a>> wrote:<o:p></o:p></p>
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<p class="MsoNormal">Howdy folks,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">I’m trying to implement something with kea and I was hoping to pick the hive brain.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">What I’m trying to do is, on a request for DHCP, format a JSON query to a network service that will return a hostname and IP address. Then, generate a lease (using memfile) which then gets returned to the requesting client. I can do all
that in a shell, which I was using the kea-hook-runscript hook library to do. The first part all works well. The problem comes in trying to update the memfile. The kea-hook-runscript calls an external shell to do the work, and blocks waiting on that shell
to exit. Because it’s blocked, I can’t issue any lease commands through the control channel to do the updates I desire.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">I’m not sure how to get around this, I feel like making the external callout non-blocking would introduce race conditions that would bite me later on. The only real solution I see is use a 3<sup>rd</sup>-party DB like mysql and handle the
updates within the script, but that introduces overhead that I’m unwilling to do.
<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">I’m not much of a programmer, so saying “Build your own hook library” really isn’t an option given the time constraints I’m under. I feel like I might eventually be able to it, but I simply don’t have the time.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Does anyone have any suggestions? Any constructive criticism is appreciated.<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">Thanks,<o:p></o:p></p>
<p class="MsoNormal"> <o:p></o:p></p>
<p class="MsoNormal">-Tom<o:p></o:p></p>
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<p class="MsoNormal"><span style="font-size:12.0pt;font-family:"Times New Roman","serif"">_______________________________________________<br>
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<a href="mailto:Kea-users@lists.isc.org">Kea-users@lists.isc.org</a><br>
<a href="https://lists.isc.org/mailman/listinfo/kea-users">https://lists.isc.org/mailman/listinfo/kea-users</a><o:p></o:p></span></p>
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