K2 testing final

[Ankith-Confluent]

This PR refactors the librdkafka test suite to improve cloud compatibility by adding configurable options in test.conf. This enables better test portability and maintainability across different Kafka environments.

Changes

1. Configurable Test Framework

• test.skip.idempotent: Skip tests requiring idempotent producer (replaces -I flag)
• test.supported.acks: Configure supported acknowledgment values (e.g., -1,0,1)
• test.sleep.multiplier: Configurable sleep multiplier for different environments. Multiplies explicit sleep_for() delays for cluster state propagation (set 0 to skip sleeps), different from test.timeout.multiplier which multiplies API operation timeouts (can't be disabled).
• test.timeout.multiplier: Unified timeout scaling (existing feature, now consistently used)
• test.skip.numbers: Skip specific tests by number (comma-separated list)

2. Topic Cleanup

• Many tests were creating topics, but not deleting them.
• Added topic delete utility.

3. Replication Factor

• Changed hardcoded replication factors to use broker defaults (-1)

4. Preprocessor Directives for Version Compatibility

• Added preprocessor directives to support librdkafka versions 2.0 through 2.11

🔧 Configuration Examples

test.timeout.multiplier=2.0
test.sleep.multiplier=3.0
test.supported.acks=-1,1
test.skip.idempotent=true
test.skip.numbers=0011,0055,0063,0068,0081,0086

[k-raina]

Please update PR description, since there are large amount of changes. It will help with review

[Copilot]

Pull Request Overview

This PR implements testing support for K2 (Kafka-compatible) clusters by adding comprehensive configuration options and adapting tests to work with different cluster environments. The changes enable tests to handle varying acks support, idempotent producer requirements, and cloud/managed cluster constraints.

• Added K2 cluster detection and configuration support with timeout adjustments
• Implemented flexible acks value testing and cluster-specific feature detection
• Enhanced test framework with version-aware APIs and graceful degradation for older librdkafka versions

Reviewed Changes

Copilot reviewed 91 out of 91 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
tests/testshared.h	Added function declarations for K2 cluster support, acks validation, and topic creation utilities
tests/test.h	Added TEST_F_IDEMPOTENT_PRODUCER flag and K2 cluster variable declaration
tests/test.conf.example	Added configuration options for test skipping, acks support, sleep multipliers, and idempotent producer handling
tests/test.c	Core implementation of K2 support, acks validation, test skipping logic, and enhanced test framework functions
Multiple test files	Updated individual tests to use broker-default replication factors, version-aware APIs, and conditional test execution

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[Copilot]

Pull Request Overview

Copilot reviewed 95 out of 95 changed files in this pull request and generated 10 comments.

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[k-raina]

First round of review. Left some comments!

[k-raina]

Thanks for changes!
Few comments for rest of files.