https://jira.opendaylight.org This file is an XML representation of an issue en-us 8.20.10 820010 22-06-2022 https://jira.opendaylight.org/browse/NETCONF-563 netconf <p>This utility method is used by NETCONF plugin to create a filter expression and write it out. Unfortunately this functionality relied leaf nodes having a null value, which would in turn be recognized and ignored by codecs.</p> <p>Null-valued leaves are no longer available, which breaks the ability to create filters for simple leaves, rendering sal-netconf-connector inoperable for requests to read individual leaves.</p> NETCONF-563

NetconfMessageTransformUtil.toFilterStructure() fails for leaf instance identifiers

Bug High Resolved Done Robert Varga Robert Varga Fri, 24 Aug 2018 13:27:09 +0000 Wed, 8 Dec 2021 12:29:56 +0000 Tue, 4 Sep 2018 08:47:24 +0000 Oxygen Fluorine Neon Oxygen SR4 Fluorine SR1 netconf 0 1 <p>Stack trace of evidence:</p> <div class="preformatted panel" style="border-width: 1px;"><div class="preformattedContent panelContent"> <pre>java.lang.IllegalStateException: Value has not been set     at com.google.common.base.Preconditions.checkState(Preconditions.java:504) [81:com.google.guava:23.6.1.jre]     at org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.AbstractImmutableNormalizedNodeBuilder.getValue(AbstractImmutableNormalizedNodeBuilder.java:33) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafNodeBuilder.build(ImmutableLeafNodeBuilder.java:27) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.builder.impl.ImmutableLeafNodeBuilder.build(ImmutableLeafNodeBuilder.java:17) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToSimpleNodes.create(InstanceIdToSimpleNodes.java:50) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToCompositeNodes.create(InstanceIdToCompositeNodes.java:105) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToCompositeNodes.create(InstanceIdToCompositeNodes.java:105) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToCompositeNodes.create(InstanceIdToCompositeNodes.java:105) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToCompositeNodes.create(InstanceIdToCompositeNodes.java:105) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.InstanceIdToCompositeNodes.create(InstanceIdToCompositeNodes.java:105) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes.fromInstanceId(ImmutableNodes.java:147) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.yangtools.yang.data.impl.schema.ImmutableNodes.fromInstanceId(ImmutableNodes.java:110) [323:org.opendaylight.yangtools.yang-data-impl:2.0.6.1]     at org.opendaylight.netconf.sal.connect.netconf.util.NetconfMessageTransformUtil.toFilterStructure(NetconfMessageTransformUtil.java:187) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.util.NetconfRpcStructureTransformer.toFilterStructure(NetconfRpcStructureTransformer.java:46) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getConfig(NetconfBaseOps.java:185) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getConfigRunning(NetconfBaseOps.java:223) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.util.NetconfBaseOps.getConfigRunningData(NetconfBaseOps.java:199) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.sal.tx.ReadOnlyTx.readConfigurationData(ReadOnlyTx.java:43) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3]     at org.opendaylight.netconf.sal.connect.netconf.sal.tx.ReadOnlyTx.read(ReadOnlyTx.java:67) [301:org.opendaylight.netconf.sal-netconf-connector:1.7.3] </pre> </div></div> <p>One way of fixing this would be to store Empty instance in the leaf, but that would only paper over the problem, leading to a failure to serialize the data, as both JSON and XML codecs rely on schema information to select the correct codec – leading to ClassCastException when the leaf's value is accessed for serialization.</p> <p>Another way would be to select an 'empty' value, which could work except numeric types do not have such a value – leading to a partially-working solution.</p> <p>This is an extreme edge case, which should be handled in NETCONF. toFilterStructure() is returning an anyxml node, for which it really needs only an Element with proper structure to use in DOMSource. Current code does this rather inefficiently by creating a NormalizedNode from YangInstanceIdentifier and then instantiating XML codec pipeline to encode that into the target Element.</p> <p>Skipping the NormalizedNode/codec steps will remove the edge case and also improve the performance of this method.</p> <p>The code looks like this, making it clear there is block we can replace:</p> <div class="code panel" style="border-width: 1px;"><div class="codeContent panelContent"> <pre class="code-java">        <span class="code-keyword">final</span> Element element = XmlUtil.createElement(BLANK_DOCUMENT, NETCONF_FILTER_QNAME.getLocalName(),                 Optional.of(NETCONF_FILTER_QNAME.getNamespace().toString()));         element.setAttributeNS(NETCONF_FILTER_QNAME.getNamespace().toString(), NETCONF_TYPE_QNAME.getLocalName(),                 <span class="code-quote">"subtree"</span>);         <span class="code-keyword">try</span> {             NetconfUtil.writeNormalizedNode(ImmutableNodes.fromInstanceId(ctx, identifier), <span class="code-keyword">new</span> DOMResult(element),                 SchemaPath.ROOT, ctx);         } <span class="code-keyword">catch</span> (IOException | XMLStreamException e) {             <span class="code-keyword">throw</span> <span class="code-keyword">new</span> IllegalStateException(<span class="code-quote">"Unable to serialize filter element <span class="code-keyword">for</span> path "</span> + identifier, e);         }         anyXmlBuilder.withValue(<span class="code-keyword">new</span> DOMSource(element)); </pre> </div></div> <p>So here we need the XML serializer to deal with leaf values (in case of NodeIdentifierWithPredicates), but for that we certainly do not need a NormalizedNode representation of the YangInstanceIdentifier. Hence NetconfUtil should grow a writeYangInstanceIdentifier(), which will instantiate the XML codec (to deal with values) and drive it using NormalizedNodeStreamWriter interface based on the content of YangInstanceIdentifier.</p> Relates YANGTOOLS-898 NETCONF-833 Development Rank 0|i03i47: