After we upgraded to 1.2.12, we've been having issues with libvirt... it
complains that our formerly valid guest definitions are now invalid:
error: Failed to start domain XXXX
error: internal error: Cannot instantiate filter due to unresolvable
variables or unavailable list elements: DHCPSERVER
We looked into this, and found that it's the XML validation that's failing:
# xmllint --noout --relaxng "/share/libvirt/schemas/domain.rng"
XXXX.xml --recover
Relax-NG validity error : Extra element devices in interleave
test.xml:1: element domain: Relax-NG validity error : Element domain
failed to validate content
test.xml fails to validate
And, a minimal domain XML to reproduce it (this won't boot, but it shows
the issue):
<domain type='kvm' id='65'>
<name>XXXX</name>
<uuid>b602b5f2-b9d7-43bd-a949-acc7eeeb9f8f</uuid>
<memory unit='KiB'>1048576</memory>
<devices>
<interface type='bridge'>
<filterref filter='myfilter'>
<parameter name='CTRL_IP_LEARNING' value='none'/>
<parameter name='DHCPSERVER' value='104.156.226.10'/>
<parameter name='IP' value='104.207.129.11'/>
<parameter name='IP6_ADDR' value='2001:19f0:300:2102::'/>
<parameter name='IP6_MASK' value='64'/>
</filterref>
</interface>
</devices>
</domain>
The cause seems to be having multiple parameters in a <filterref> block.
We applied the following patch to fix it:
diff -ur src_clean/docs/schemas/domaincommon.rng
src/docs/schemas/domaincommon.rng
--- src_clean/docs/schemas/domaincommon.rng 2015-01-23
06:46:24.000000000 -0500
+++ src/docs/schemas/domaincommon.rng 2015-03-10 11:30:42.057441342 -0400
@@ -4468,6 +4468,7 @@
<data type="NCName"/>
</attribute>
<optional>
+ <zeroOrMore>
<element name="parameter">
<attribute name="name">
<ref name="filter-param-name"/>
@@ -4476,6 +4477,7 @@
<ref name="filter-param-value"/>
</attribute>
</element>
+ </zeroOrMore>
</optional>
</define>