[Feature-18689][task-flink-sqlgateway] Add FLINK_SGW task plugin

[macdoor]

Was this PR generated or assisted by AI?

YES — the plugin code was initially developed with AI-assisted tooling (Cursor) and this port/adaptation (rebasing onto dev-SNAPSHOT, adopting the SqlSourceType enum from task-api, refactor for testability, and unit-test authoring) was assisted by an AI agent (Hermes). All changes were human-reviewed and verified by build + unit tests.

Purpose of the pull request

Add a new task plugin FLINK_SGW that submits SQL scripts to a Flink SQL Gateway through its JDBC driver (flink-sql-jdbc-driver), enabling DolphinScheduler to schedule batch SQL workloads without a local Flink client.

The task type is named FLINK_SGW instead of the longer FLINK_SQL_GATEWAY: the long name wraps and breaks the DAG node / task-type picker layout; the short alias reuses the Flink family icon and keeps nodes readable (see linked issue).

Brief change log

• Add dolphinscheduler-task-flink-sqlgateway module (FlinkSqlGatewayParameters / FlinkSqlGatewayTask / FlinkSqlGatewayTaskChannel / FlinkSqlGatewayTaskChannelFactory)
• Register the module in dolphinscheduler-task-plugin/pom.xml and wire it into dolphinscheduler-task-all
• Register FLINK_SGW in task-type-config.yaml
• UI: task-type constants, store registration, node form fields (use-flink-sqlgateway), format-data serialization, icon fallback (reuse flink.png), locales (en/zh)
• use-resources field helper gains optional limit / field parameters to support the init-script resource field

Design notes:

• Script sources reuse org.apache.dolphinscheduler.plugin.task.api.enums.SqlSourceType (SCRIPT / FILE) introduced by [Improvement-18019][task-sql] Support SQL from resource file and parameter placeholders #18020, instead of duplicating constants
• Init + main script resolution share one code path; statement splitting and comment-stripping are package-private static methods covered by plain JUnit tests (no Mockito)
• The shaded plugin jar is self-contained (bundles the Flink SQL Gateway JDBC driver); task-api / common stay provided

Verify this pull request

This change added tests and can be verified as follows:

• mvn test -pl dolphinscheduler-task-plugin/dolphinscheduler-task-flink-sqlgateway -am — FlinkSqlGatewayParametersTest (12 checks: parameter validation across SCRIPT/FILE combinations, resource aggregation, JDBC property filtering) and FlinkSqlGatewayTaskTest (statement splitting incl. regex-special separators, leading comment/blank stripping)
• mvn package -pl dolphinscheduler-task-plugin/dolphinscheduler-task-flink-sqlgateway -am builds the shaded jar cleanly
• The plugin binary has been deployed and exercised in an internal production environment since 2026-03 (scheduled batch SQL through a dedicated SQL Gateway), which motivated the naming and the parameter-placeholder handling

[SbloodyS]

You should integrate it into flink task plugin.

[macdoor]

SQL Gateway and the existing Flink SQL path are different runtimes, so this should stay a separate task type.

FlinkTask extends AbstractYarnTask. Its SQL mode always shells out to ${FLINK_HOME}/bin/sql-client.sh on the worker, and cancel/app-id tracking assume a local process. FLINK_SGW talks to a remote Gateway over JDBC (flink-sql-jdbc-driver), needs no local Flink client, and cancels via statement.cancel(). Folding that into programType=SQL or a new deployMode means overriding handle()/cancel() and mixing two parameter models (YARN queue/slots/inline script vs JDBC URL, resource-center files, statement separator). The current sql-client.sh path has to stay; this cannot replace it.

Same split already exists for DINKY (external control plane) and FLINK_STREAM (different lifecycle). task-flink also has no Flink dependencies today. Adding the JDBC driver there would be shaded into task-flink-stream, which depends on task-flink and shades it with no filter.

Happy to colocate both SPI factories in dolphinscheduler-task-flink if the concern is a new Maven module. The task type should remain FLINK_SGW: getName() is persisted on the task definition, and the two execution paths should not share one handle().

[SbloodyS]

I'm -1 on this.

[macdoor]

Integrated this into the existing FLINK task plugin, as requested.

sqlSubmitType absent or CLIENT keeps sql-client.sh. SQL_GATEWAY submits over JDBC. Follow-up: #18693

Closing this PR.

[macdoor]

Closed in favor of #18693.