Flink k8s operator hardcodes `--host` parameter to job args and `CliRunner` fails

[velo]

Problem

When running in Flink 2.x standalone application mode via the Flink Kubernetes Operator, the container entrypoint passes --host <IP> to the application jar's main class:

/docker-entrypoint.sh standalone-job --host 10.11.35.147 --planfile /opt/flink/usrlib/flink-files/compiled-plan.json ...

The flink-sql-runner's CliRunner doesn't recognize --host, causing startup failure:

Unknown options: '--host', '10.11.35.147'
Usage: SqlRunner [-hV] [-c=<configDir>] [-m=<mode>] [-p=<planFile>]
                 [-s=<sqlFile>] [-u=<udfPath>]

Root Cause

In Flink 2.x, the docker-entrypoint.sh script for standalone-job mode now forwards all remaining arguments (including --host) to the user's main class. This is a behavior change from Flink 1.x.

Solution

Add --host as an optional ignored parameter in CliRunner.java:

@Option(names = {"--host"}, description = "Host address (passed by Flink runtime, ignored)")
private String host;

Impact

This is blocking Flink 2.x deployments via the Kubernetes Operator with mode: standalone.

Related

• cloud-compilation branch: bump-flink-sql-runner-version
• Flink Operator 1.13.0 with flinkVersion: v2_1

[velo]

pod is restarting due to:

2025-12-03 23:26:01.529 [flink-pekko.actor.default-dispatcher-10] INFO  com.datasqrl.flinkrunner.CliRunner - Executing flink-sql-runner: [--host, 10.11.35.147, --planfile, /opt/flink/usrlib/flink-files/compiled-plan.json, --config-dir, 
/opt/flink/usrlib/flink-files, --udfpath, /opt/flink/usrlib/flink-files/jars]
Unknown options: '--host', '10.11.35.147'
Usage: SqlRunner [-hV] [-c=<configDir>] [-m=<mode>] [-p=<planFile>]
                 [-s=<sqlFile>] [-u=<udfPath>]
Runs SQL scripts using Flink TableEnvironment.
  -c, --config-dir=<configDir>
                            Directory containing configuration YAML file.
  -h, --help                Show this help message and exit.
  -m, --mode=<mode>         Flink runtime execution mode to apply to the given
                              SQL program. Valid values: STREAMING, BATCH,
                              AUTOMATIC.
  -p, --planfile=<planFile> Compiled plan JSON file.
  -s, --sqlfile=<sqlFile>   SQL file to execute.
  -u, --udfpath=<udfPath>   Path to UDFs.
  -V, --version             Print version information and exit.
2025-12-03 23:26:01.656 [StandaloneApplicationClusterEntryPoint shutdown hook] INFO  org.apache.flink.runtime.entrypoint.ClusterEntrypoint - Shutting StandaloneApplicationClusterEntryPoint down with application status UNKNOWN. Diagnostics Cluster 
entrypoint has been closed externally.. 

[ferenc-csaky]

The suggested solution is an ugly workaround, not a real fix. This is messed up in the K8s operator, we should not do anything with the --host option. I think enabling unknown options in the CliRunner should be the solution here, which will also make sure we won't end up in the same situation with another field 6 months later.