[BUG] Require an optional JvmInfo Field

[Bzil]

What is the bug?

In class NodeJvmInfo at row 94 the field usingBundledJdk is expected as not null but in server side code, this field is nullable https://github.com/opensearch-project/OpenSearch/blob/main/server/src/main/java/org/opensearch/monitor/jvm/JvmInfo.java#L235 https://github.com/opensearch-project/OpenSearch/blob/main/server/src/main/java/org/opensearch/monitor/jvm/JvmInfo.java#L310

How can one reproduce the bug?

Call _nodes
See if you got response with jvm field like that :

"jvm": {
        "pid": 61,
        "version": "17.0.9",
        "vm_name": "OpenJDK 64-Bit Server VM",
        "vm_version": "17.0.9+9",
        "vm_vendor": "Red Hat, Inc.",
        "bundled_jdk": false,
        "using_bundled_jdk": null,
        "start_time_in_millis": 1713767662129,
        "mem": {
          "heap_init_in_bytes": 3183476736,
          "heap_max_in_bytes": 3183476736,
          "non_heap_init_in_bytes": 7667712,
          "non_heap_max_in_bytes": 0,
          "direct_max_in_bytes": 0
        },
        "gc_collectors": [
          "G1 Young Generation",
          "G1 Old Generation"
        ],
        "memory_pools": [
          "CodeHeap 'non-nmethods'",
          "Metaspace",
          "CodeHeap 'profiled nmethods'",
          "Compressed Class Space",
          "G1 Eden Space",
          "G1 Old Gen",
          "G1 Survivor Space",
          "CodeHeap 'non-profiled nmethods'"
        ],
        "using_compressed_ordinary_object_pointers": "true",
        "input_arguments": [
          "-XX:+UseG1GC",
          "-XX:G1ReservePercent=25",
          "-XX:InitiatingHeapOccupancyPercent=30",
          "-XX:+ExitOnOutOfMemoryError",
          "-Xss1m",
          "-Xms3036m",
          "-Xmx3036m",
          "-XX:+HeapDumpOnOutOfMemoryError",
          "--add-opens=java.base/java.io=ALL-UNNAMED",
          "-Dopensearch.path.conf=/etc/elasticsearch",
          "-Dopensearch.transport.cname_in_publish_address=true",
          "-Djava.awt.headless=true",
          "-Dfile.encoding=UTF-8",
          "-Djna.nosys=true",
          "-Djdk.io.permissionsUseCanonicalPath=true",
          "-Dio.netty.noUnsafe=true",
          "-Dio.netty.noKeySetOptimization=true",
          "-Dio.netty.recycler.maxCapacityPerThread=0",
          "-Dlog4j2.formatMsgNoLookups=true",
          "-Dlog4j.shutdownHookEnabled=false",
          "-Dlog4j2.disable.jmx=true",
          "-Dlog4j.skipJansi=true",
          "-Dopensearch.path.home=/opt/opensearch1",
          "-Dsecurity.default_init.dir=/etc/elasticsearch/opensearch-security",
          "-Des.search.ignore_awareness_attributes=false"
        ]
      },

Try to parse it, See NPE

java.lang.NullPointerException: null
	at org.opensearch.client.json.ObjectDeserializer$FieldObjectDeserializer.deserialize(ObjectDeserializer.java:82)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:185)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:146)
	at org.opensearch.client.json.JsonpDeserializer.deserialize(JsonpDeserializer.java:87)
	at org.opensearch.client.json.ObjectBuilderDeserializer.deserialize(ObjectBuilderDeserializer.java:91)
	at org.opensearch.client.json.DelegatingDeserializer$SameType.deserialize(DelegatingDeserializer.java:55)
	at org.opensearch.client.json.ObjectDeserializer$FieldObjectDeserializer.deserialize(ObjectDeserializer.java:81)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:185)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:146)
	at org.opensearch.client.json.JsonpDeserializer.deserialize(JsonpDeserializer.java:87)
	at org.opensearch.client.json.ObjectBuilderDeserializer.deserialize(ObjectBuilderDeserializer.java:91)
	at org.opensearch.client.json.DelegatingDeserializer$SameType.deserialize(DelegatingDeserializer.java:55)
	at org.opensearch.client.json.JsonpDeserializerBase$StringMapDeserializer.deserialize(JsonpDeserializerBase.java:369)
	at org.opensearch.client.json.JsonpDeserializerBase$StringMapDeserializer.deserialize(JsonpDeserializerBase.java:355)
	at org.opensearch.client.json.JsonpDeserializer.deserialize(JsonpDeserializer.java:87)
	at org.opensearch.client.json.ObjectDeserializer$FieldObjectDeserializer.deserialize(ObjectDeserializer.java:81)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:185)
	at org.opensearch.client.json.ObjectDeserializer.deserialize(ObjectDeserializer.java:146)
	at org.opensearch.client.json.JsonpDeserializer.deserialize(JsonpDeserializer.java:87)
	at org.opensearch.client.json.ObjectBuilderDeserializer.deserialize(ObjectBuilderDeserializer.java:91)
	at org.opensearch.client.json.DelegatingDeserializer$SameType.deserialize(DelegatingDeserializer.java:55)
	at org.opensearch.client.transport.rest_client.RestClientTransport.decodeResponse(RestClientTransport.java:360)
	at org.opensearch.client.transport.rest_client.RestClientTransport.getHighLevelResponse(RestClientTransport.java:326)
	at org.opensearch.client.transport.rest_client.RestClientTransport.performRequest(RestClientTransport.java:148)
	at org.opensearch.client.opensearch.nodes.OpenSearchNodesClient.info(OpenSearchNodesClient.java:145)

What is the expected behavior?

Perhaps make this fiels optional

What is your host/environment?

OS : Fedora Linux 38
Java : OpenJDK 64-Bit Server VM : 17.0.9
Open Search 1.3.13, trying to migrate to 2.14

[dblock]

Looks like a bug. Want to write a test and fix it?

FYI, we have recently merged a beginning of a code generator that aims to resolve this entire class of problems (#366). There are a few things you can do to help:

1. Ensure that the specification for these APIs in https://github.com/opensearch-project/opensearch-api-specification is correct, and add tests for them in that repo.
2. Write tests in this repo for the scenarios that are broken like the ones you're reporting and manually fix any of these bugs.

The combination will ensure that as we switch to the generator we're not introducing regressions.

[Bzil]

Hi @dblock
I'm not familiar with writing a openapi spec, when I try to run opensearch-api-specification tests all of them are in error. So it's quite weird.

[dblock]

@Bzil i am here to help! Feel free to open issues in that repo. Do read the dev guide, some things require a bit of a setup.