added OpenSearchClient as parameter to pass custom instance

[renjth-81]

Description

Added OpenSearchClient as a parameter to allow custom OpenSearchClient instance to be passed.

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[davsclaus]

you need to also rebuild camel-catalog, and some code in component and endpoint dsl

[davsclaus]

There are uncommitted changes
HEAD detached at pull/24320/merge
Changes not staged for commit:
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modified: catalog/camel-catalog/src/generated/resources/org/apache/camel/catalog/components/opensearch.json
modified: dsl/camel-componentdsl/src/generated/java/org/apache/camel/builder/component/dsl/OpensearchComponentBuilderFactory.java
modified: dsl/camel-endpointdsl/src/generated/java/org/apache/camel/builder/endpoint/dsl/OpensearchEndpointBuilderFactory.java

[oscerd]

Thanks for the contribution, @renjth-81 — being able to pass a custom OpenSearchClient is a useful addition, and the generated catalog/DSL files are all correctly regenerated. However, there's a blocking correctness problem in the current implementation that CI is also catching, so I'm requesting changes.

Blocker: the cached transport captures a null RestClient → NPE on every exchange

OpensearchProducer now builds and caches openSearchClient in its constructor:

• the constructor sets this.client = endpoint.getClient(); then this.openSearchClient = createDefaultOpenSearchClient();
• createDefaultOpenSearchClient() builds new OpenSearchClient(new RestClientTransport(client, ...)), but only calls startClient() when configuration.isDisconnect() && client == null.

In the standard configuration (a RestClient built from hostAddresses, no autowired client), endpoint.getClient() is null at construction time — the component creates the endpoint with a null client by default (OpensearchComponent.java:91), and the real RestClient is created lazily later in doStart() → startClient() (OpensearchProducer.java, the double-checked-locking block around lines 452–467). disconnect defaults to false (OpensearchConfiguration.java:60), so createDefaultOpenSearchClient() does not start the client and ends up wrapping a RestClientTransport around a null RestClient.

process() then does OpenSearchTransport transport = openSearchClient._transport(); and reuses that cached transport, so every exchange dereferences the null RestClient:

java.lang.NullPointerException: Cannot invoke
  "org.opensearch.client.RestClient.performRequestAsync(...)" because "this.restClient" is null

This is exactly what CI is failing on — build (17, false) and build (25, false) are both red, with OpensearchPingIT.testPing and all OpensearchBulkIT.* failing with this NPE. The user-supplied-client path (endpoint.getOpenSearchClient() != null) works, but the default path — which all of the component's own integration tests exercise — is broken.

Suggested direction

Resolve the transport lazily rather than in the constructor: keep using the user-supplied OpenSearchClient when one is provided, but for the default case build the transport in process() / after doStart() once client is non-null (as the original code did). Please also keep the disconnect=true semantics in mind — the old process() rebuilt the transport per call and cleanup() closes and nulls the client after each exchange (OpensearchProducer.java, around lines 437–445), so a single cached transport would also break disconnect mode after the first exchange.

Other items

• Tests: please add a test proving a custom OpenSearchClient instance is actually honored at runtime — the new option currently has no coverage, and the existing integration tests regressed.
• Jira: apache/camel changes should be tracked by a CAMEL-XXXXX issue with the commit/PR title prefixed accordingly. Could you create one (component camel-opensearch) and update the title? The added missing files commit subject could also be made more descriptive.

For context: this PR currently shows as approved, but that review was on the very first commit (62b5af1), before the generated-files commit and before CI ran — so it predates the failures above.

Thanks again for working on this — happy to re-review once the transport init is made lazy and CI is green.

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Reviewed with Claude Code on behalf of Andrea Cosentino (@oscerd). This review was generated by an AI agent and may contain inaccuracies; please verify all suggestions before applying.

[davsclaus]

creating a new client should ideally not be done in constructors but in doInit or doStart