yang-central / yangkit

Yangkit is a toolkit for YANG(RFC7950) data model language including YANG parser,YANG data and other tools.

Yangkit

overview

Yangkit is a toolkit for YANG(RFC7950) data model language including YANG parser,YANG data and other tools.

Yangkit components

• yangkit-parser: parse YANG files and validate the parsed YANG modules
• yangkit-model-api: The APIs for YANG model
• yangkit-model-impl: The implementations for YANG model
• yangkit-xpath-api: The APIs for YANG XPATH parser,validator and evaluator.
• yangkit-xpath-impl: The Implementations for YANG XPATH parser,validator and evaluator.
• yangkit-data-api: The APIs for YANG data representation and operation.
• yangkit-data-impl: The Implementations for YANG data representation and operation.

Installation

From source

git clone https://github.com/yang-central/yangkit.git

and execute the maven command:

mvn clean install

maven dependency

yangkit-parser

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-parser</artifactId>
        <version>1.0.0</version>
    </dependency>

yangkit-model-api

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-model-api</artifactId>
        <version>1.0.0</version>
    </dependency>

yangkit-model-impl

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-model-impl</artifactId>
        <version>1.0.0</version>
    </dependency>

yangkit-xpath-api

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-xpath-api</artifactId>
        <version>1.0.0</version>
    </dependency>

yangkit-xpath-impl

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-xpath-impl</artifactId>
        <version>1.0.0</version>
    </dependency>

yangkit-data-api

    <dependency>
        <groupId>io.github.yang-central.yangkit</groupId>
        <artifactId>yangkit-data-api</artifactId>
        <version>1.0.0</version>
    </dependency>

Documentation

Please see the java doc in components.

yangkit's Issues

Enhance the YangYinParser API to work with none file-based yang sources

Currently, the YangYinParser provides 8 public methods for parsing YANG schemas, all of which are File or Directory based. This represents a tight coupling to the filesystem and can limit the usage of this API inside other libraries that don't save the schema on a traditional file system.

Is there any futures plans to refactor this API and decouple YangYinParser from how the yang schemas are stored?

The current, API

1. public static YangSchemaContext parse(List<File> yangFiles)
2. public static YangSchemaContext parse(File yangDir)
3. public static YangSchemaContext parse(File yangDir, YangSchemaContext context)
4. public static YangSchemaContext parse(String yangDir)
5. public static YangSchemaContext parse(String yangDir, String dependency, String capabilities)
6. public static YangSchemaContext parse(String yangDir, String capabilities)
7. public static YangSchemaContext parse(String yangDir, YangSchemaContext context)
8. public static YangSchemaContext parse(List<File> files, YangSchemaContext context)

Nested `while (true)`

There are two nested while(true) statements at line https://github.com/yang-central/yangkit/blob/main/yangkit-model-impl/src/main/java/org/yangcentral/yangkit/model/impl/stmt/ModuleImpl.java#L794

I tried to understand the code, but I couldn't tell why these two loops are there. Is that correct and I'm missing something or this code can be simplified a bit?

Exception in thread "main" java.lang.RuntimeException: org.yangcentral.yangkit.model.api.codec.YangCodecException: invalid value.

tool：yangkit-data-xml-codec
version：1.4.0

Exception in thread "main" java.lang.RuntimeException: org.yangcentral.yangkit.model.api.codec.YangCodecException: invalid value.
at org.yangcentral.yangkit.data.impl.model.LeafListDataImpl.(LeafListDataImpl.java:23)
at org.yangcentral.yangkit.data.impl.builder.YangDataBuilder.getYangData(YangDataBuilder.java:53)
at org.yangcentral.yangkit.data.codec.xml.LeafListDataXmlCodec.buildData(LeafListDataXmlCodec.java:20)
at org.yangcentral.yangkit.data.codec.xml.LeafListDataXmlCodec.buildData(LeafListDataXmlCodec.java:10)
at org.yangcentral.yangkit.data.codec.xml.YangDataXmlCodec.deserialize(YangDataXmlCodec.java:99)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.buildChildrenData(YangDataDocumentXmlCodec.java:65)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.buildChildrenData(YangDataDocumentXmlCodec.java:93)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.buildChildrenData(YangDataDocumentXmlCodec.java:93)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.buildChildrenData(YangDataDocumentXmlCodec.java:93)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.deserialize(YangDataDocumentXmlCodec.java:109)
at org.yangcentral.yangkit.data.codec.xml.YangDataDocumentXmlCodec.deserialize(YangDataDocumentXmlCodec.java:119)
at org.yangcentral.yangkit.data.codec.xml.YangDataParser.parse(YangDataParser.java:39)
at org.yangcentral.yangkit.data.codec.xml.YangDataParserExecutor.main(YangDataParserExecutor.java:52)
Caused by: org.yangcentral.yangkit.model.api.codec.YangCodecException: invalid value.
at org.yangcentral.yangkit.model.impl.codec.UnionStringValueCodecImpl.serialize(UnionStringValueCodecImpl.java:58)
at org.yangcentral.yangkit.model.impl.codec.UnionStringValueCodecImpl.serialize(UnionStringValueCodecImpl.java:17)
at org.yangcentral.yangkit.data.impl.model.YangDataValueStringImpl.getStringValue(YangDataValueStringImpl.java:54)
at org.yangcentral.yangkit.data.impl.model.LeafListDataImpl.(LeafListDataImpl.java:21)
... 12 more

cause by
LeafList：
3352:3885

yang：
leaf-list community-member {
type community-type;
max-elements 200;
status deprecated;
ext:advised-node "../rtp:community-attributes/rtp:community-attribute";
description
"Configure a community attribute in a BGP community list. There must be at least one community in a list, min-elements 1.";
}

typedef community-type {
type union {
type well-known-community-type;
type std-community-type;
}
description
"Type of the community members.";
}

typedef well-known-community-type {
type enumeration {
enum "internet" {
description
"The basic type of filter.";
}
enum "no-advertise" {
description
"Do not advertise to any peer.";
}
enum "no-export" {
description
"Do not export to external peers.";
}
enum "no-export-subconfed" {
description
"Do not send outside a sub-confederation.";
}
}
description
"Type definition for well-known IETF community attribute values.";
}

typedef std-community-type {
type union {
type string {
length "1..19";
pattern '((6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[1-9][0-9]{0,3}|0):(6553[0-5]|655[0-2][0-9]|65[0-4][0-9]{2}|6[0-4][0-9]{3}|[1-5][0-9]{4}|[1-9][0-9]{0,3}|0))';
}
type uint32 {
range "1..4294967040|4294967044..4294967295";
}
}
description
"Type definition for community attributes.";
}

why UnionImpl.evaluated() is false?

file: org.yangcentral.yangkit.model.impl.restriction.UnionImpl
line: 25

public boolean evaluated(Object value) {
return false;
}

when/must statement predicate insufficient check

when/must statement predicate insufficient check

The same error is reported twice.

errorTag='bad-element', severity=Warning, errorPath=source:ieee802-dot1ab-lldp.yang line:390 column:7, badElement=leaf name, errorMessage=invalid xpath:(derived-from-or-self(deref(.)/../if:type, "ianaift:ethernetCsmacd") or derived-from-or-self(deref(.)/../if:type, "ianaift:ieee8023adLag")). the node:lldp:port has no child node:if:type.
errorTag='bad-element', severity=Warning, errorPath=source:ieee802-dot1ab-lldp.yang line:390 column:7, badElement=leaf name, errorMessage=invalid xpath:(derived-from-or-self(deref(.)/../if:type, "ianaift:ethernetCsmacd") or derived-from-or-self(deref(.)/../if:type, "ianaift:ieee8023adLag")). the node:lldp:port has no child node:if:type.

Yang to Json Schema

Hi ,
can you please provide and example to convert yang to a json schema, is it supported? javadoc is not working btw

NullPointerException on typedef declaration in grouping

Hi!

Given the following yang-file null-pointer-example.yang:

module null-pointer-example {
  yang-version 1.1;
  namespace "urn:example:yangkit-bug";
  prefix bug;

  description
    "Demonstrate NullPointerException in io.github.yang-central.yangkit:yangkit-parser:1.3.5";

  revision 2023-07-25 {
  }

  typedef package-version {
    type string {
      pattern '\d+\.\d+([-.](\d+|\w+))*';
    }
  }

  grouping package-meta-data {
    typedef version {
      type package-version;
    }
  }
}

And running code like this:

YangSchemaContext schemaContext = YangYinParser.parse(List.of(new File("null-pointer-example.yang")));
schemaContext.validate();

I get the following exception:

java.lang.NullPointerException: Cannot invoke "org.yangcentral.yangkit.base.YangContext.getTypedef(String)" because "this.yangContext" is null
	at org.yangcentral.yangkit.model.impl.stmt.TypedefContainerImpl.getTypedef(TypedefContainerImpl.java:48)
	at org.yangcentral.yangkit.model.impl.stmt.TypedefContainerImpl.addTypedef(TypedefContainerImpl.java:35)
	at org.yangcentral.yangkit.model.impl.stmt.GroupingImpl.initSelf(GroupingImpl.java:164)
	at org.yangcentral.yangkit.model.impl.stmt.YangStatementImpl.init(YangStatementImpl.java:806)
	at org.yangcentral.yangkit.model.impl.stmt.YangStatementImpl.initChildren(YangStatementImpl.java:741)
	at org.yangcentral.yangkit.model.impl.stmt.YangStatementImpl.init(YangStatementImpl.java:812)
	at org.yangcentral.yangkit.model.impl.schema.YangSchemaContextImpl.validate(YangSchemaContextImpl.java:286)

I've reduced the example to be somewhat minimal to trigger the bug.

Hope there can be an easy fix for this :-)

Cheers!
/Mårten

Yang parser accepts yang schema without proper curly bracket closing

I've tried using the yang parser on the following schema that is missing three closing curly brackets (leaf definition closing, container definition closing, and module closing). Yang parser parses and validate it correctly without throwing any errors?

module a-module {
  yang-version 1.1;
  namespace "urn:example:a-module";
  prefix a;

  organization
    "Test Organization";
  contact
    "Ahmed Elhassany <mailto:[email protected]>";
  description
    "Simple Test module with one typedef and a container of one leaf";
  reference
    "testing";

  revision 2023-02-01 {
    reference
      "first revision";
  }

  typedef aType {
    type int8;
    description
      "Simple int8 type for testing";
  }

  container x {
    description
      "Test container";
    leaf aLeaf {
      type aType;
      description
        "Example leaf";

The test code I used was

package yang.test;

import org.yangcentral.yangkit.common.api.validate.ValidatorResult;
import org.yangcentral.yangkit.model.api.schema.YangSchemaContext;
import org.yangcentral.yangkit.parser.YangYinParser;

public class TestCase {
  public static void main(String[] args) throws Exception{
    YangSchemaContext yang = YangYinParser.parse("~/yangdir");
    ValidatorResult result = yang.validate();
    if (result.isOk()) {
      System.out.println("Yang Schema is valid, number of modules read is: " + yang.getModules().size());
    } else {
      System.out.println("Yang Schema is NOT valid, number of modules read is: " + yang.getModules().size());
    }
  }
}

And the output was Yang Schema is valid, number of modules read is: 1. I don't this is a correct behavior by yangkit: I was expecting this value to be invalid. FYI, pyang and libyang won't accept this schema as a valid one.

javadoc links are not working

Hi all,

I found your project very interesting, I would like to take a look at the documentation to find minimal examples for parsing YANG model, generating YANG instance data, etc.

But the javadoc links are not working, pointing to not found links. Are you planning to fix this issue?

Thanks,
Balazs