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Hello everyone,
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<div class="">I am running an HA (hot standby) Kea setup in Kubernetes. I do not want to hard-code service IPs, so I switched to headless services instead, hoping to be able to provide (fest) hostnames in the HA configuration:</div>
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<div class="">[…]</div>
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<div class="">"parameters": {</div>
<div class=""> "high-availability": [</div>
<div class=""> {</div>
<div class=""> "this-server-name": "secondary",</div>
<div class=""> "mode": "hot-standby",</div>
<div class=""> "heartbeat-interval": 10000,</div>
<div class=""> "max-response-delay": 60000,</div>
<div class=""> "max-ack-delay": 10000,</div>
<div class=""> "max-unacked-messages": 0,</div>
<div class=""> "max-unacked-clients": 0,</div>
<div class=""> "peers": [</div>
<div class=""> {</div>
<div class=""> "name": "primary",</div>
<div class=""> "url": "<a href="http://dhcp-prim-headless-svc:8000" class="">http://dhcp-prim-headless-svc:8000</a>/“, <- does not seem to be supported</div>
<div class=""> "role": "primary",</div>
<div class=""> "auto-failover": true</div>
<div class=""> },</div>
<div class=""> {</div>
<div class=""> "name": "secondary",</div>
<div class=""> "url": "<a href="http://dhcp-second-headless-svc:8000" class="">http://dhcp-second-headless-svc:8000</a>/“, <- same here</div>
<div class=""> "role": "standby",</div>
<div class=""> "auto-failover": true</div>
<div class=""> }</div>
<div class=""> ]</div>
<div class=""> }</div>
<div class=""> ]</div>
<div class="">}</div>
</div>
<div class="">[…]</div>
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<div class="">However, the Kea container fails to start with the error message that the address cannot be resolved:</div>
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<div class="">363 18:16:52.313 kea-dhcp4.hooks HOOKS_STD_CALLOUT_REGISTERED hooks library /usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_ha.so registered standard callout for hook leases4_committed at address 0x7f20d4739360</div>
<div class="">363 18:16:52.313 kea-dhcp4.ha-hooks HA_CONFIGURATION_FAILED failed to configure High Availability hooks library: bad url '<a href="http://dhcp-prim-headless-svc:8000/': Failed to convert string to address 'dhcp-prim-headless-svc" class="">http://dhcp-prim-headless-svc:8000/':
Failed to convert string to address 'dhcp-prim-headless-svc</a>': Invalid argument for server primary</div>
<div class="">363 18:16:52.313 kea-dhcp4.hooks HOOKS_LOAD_ERROR 'load' function in hook library /usr/lib/x86_64-linux-gnu/kea/hooks/libdhcp_ha.so returned error 1</div>
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<div class="">The headless service is perfectly pingable from other containers in the pod, so no DNS general problem there.</div>
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<div class="">I also stumbled upon a unit test, indicating that hostnames are not supported in the configuration, <a href="https://gitlab.isc.org/isc-projects/kea/-/blob/master/src/hooks/dhcp/high_availability/tests/ha_config_unittest.cc#L651-L677" class="">https://gitlab.isc.org/isc-projects/kea/-/blob/master/src/hooks/dhcp/high_availability/tests/ha_config_unittest.cc#L651-L677</a>.
However, the HA design document, <a href="https://gitlab.isc.org/isc-projects/kea/-/wikis/designs/High-Availability-Design,has" class="">https://gitlab.isc.org/isc-projects/kea/-/wikis/designs/High-Availability-Design,</a> clearly *has* hostnames in its showcase
configuration.</div>
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<div class="">So, can someone, kindly, hint me if that’s supported or not? If the latter is the case, I will just open a feature request.</div>
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<div class="">For the developers: thanks for the great work, keep it up!</div>
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<div class="">Best,</div>
<div class=""> Damyan Y.</div>
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<p class="p1"><span class="s1"><b class="">Damyan Yordanov</b></span><o:p class=""></o:p></p>
<p class="p1"><span class="s1">BTP Core FP R&C Gardener (SE)</span><o:p class=""></o:p></p>
<p class="p2"><span class="s2"><b class="">SAP SE, </b></span><span class="s1">Dietmar-Hopp-Allee 16, 69190 Walldorf, Germany</span></p>
<p class="p1"><span class="s1">T +49 6227 7-65764, M +49 160 90 842 652, <a href="mailto:damyan.yordanov@sap.com" class="">damyan.yordanov@sap.com</a></span></p>
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