NIFI-13684 Set Cluster Status HTTP Code based on Connection

[exceptionfactory]

Summary

NIFI-13684 Updates the nifi-runtime Management Server /health/cluster HTTP response to return HTTP 503 when the cluster connection state is not CONNECTED or CONNECTING. This change preserves the current behavior of the nifi.sh cluster-status command to return the information to the console, but provides an HTTP response code that corresponds to the content of the connection state.

Tracking

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Issue Tracking

• Apache NiFi Jira issue created

Pull Request Tracking

• Pull Request title starts with Apache NiFi Jira issue number, such as NIFI-00000
• Pull Request commit message starts with Apache NiFi Jira issue number, as such NIFI-00000

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Verification

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Build

• Build completed using mvn clean install -P contrib-check
  • JDK 21

Licensing

• New dependencies are compatible with the Apache License 2.0 according to the License Policy
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Documentation

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[bbende]

Looks good and verified calling nifi.sh cluster-status