[Bug] Revert FlinkEnv config path persistence regression

[michael1991]

What is the purpose of the change

This PR reverts the regression introduced by 81b8161 from v2.1.7.

That commit changed FlinkEnv.doSetFlinkConf() to persist the absolute Flink config file path into t_flink_env.flink_conf.

However, existing read paths still expect flink_conf to be compressed Base64 content and call DeflaterUtils.unzipString(...), for example:

• /flink/env/get
• FlinkEnv.convertFlinkYamlAsMap()
• FlinkEnvServiceImpl.getFlinkConfig(...)

When flink_conf contains a path such as:

  /data/flink/flink-1.20.5/conf/config.yaml

  Base64 decoding fails with:

  IllegalArgumentException: Illegal base64 character 2d

  This causes Flink Env view/edit and Application edit to return HTTP 500.

Brief change log

• Revert FlinkEnv.doSetFlinkConf() to persist compressed config content.
• Read the resolved Flink config file content.
• Store t_flink_env.flink_conf as DeflaterUtils.zipString(...).

Verifying this change

Manually verified with Flink 1.20.5:

1. Create a Flink Env with flink_home=/data/flink/flink-1.20.5.
2. Confirm t_flink_env.flink_conf stores compressed Base64 content, not the config file path.
3. Call /flink/env/get.
4. Open the Application edit page.
5. No Illegal base64 character 2d error occurs.

Does this pull request potentially affect one of the following parts

• Dependencies: no
• The public API: no
• The schema: no
• The default values of configurations: no
• The behavior of t_flink_env.flink_conf: yes, restores the expected behavior used by existing read paths

[sonarqubecloud]

Quality Gate passed

Issues
1 New issue
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[michael1991]

Related issues:

• [Bug] Exception while viewing Flink Conf Configuration on web page #4323
• [Bug] Release job not work #4316