server: fix TLS credentials not passed to tiflow in old architecture mode

[dumanshu]

What problem does this PR solve?

Issue Number: close #3718

When TiCDC runs in old architecture mode (delegating to tiflow), TLS credentials passed via CLI flags (--ca, --cert, --key) are not transferred to serverConfig.Security. This causes TiCDC to connect to PD using HTTP instead of HTTPS, resulting in connection failures for TLS-enabled clusters.

What is changed and how it works?

Root cause: In runTiFlowServer(), the code marshals o.serverConfig to JSON and passes it to tiflow. However, o.serverConfig.Security was never populated from the CLI flags before marshaling. The tiflow complete() function then copies from the empty o.ServerConfig.Security back to cfg.Security, overwriting any credentials.

Fix:

1. Call o.getCredential() to populate serverConfig.Security before JSON marshaling
2. Remove redundant oldOptions.CaPath/CertPath/KeyPath/AllowedCertCN assignments since credentials are now in ServerConfig.Security

This is similar to how complete() does it for new architecture mode at line 161.

Check List

Tests

• Unit test

Questions

Will it cause performance regression or break compatibility?

No

Do you need to update user documentation, design documentation or monitoring documentation?

No

Release note

Fix TLS credentials not being passed to tiflow when running TiCDC in old architecture mode, which caused connection failures to TLS-enabled PD clusters.

[ti-chi-bot]

Hi @dumanshu. Thanks for your PR.

I'm waiting for a pingcap member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

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[gemini-code-assist]

Summary of Changes

Hello @dumanshu, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request fixes a critical bug in TiCDC's old architecture mode that prevented it from connecting to TLS-enabled PD clusters. The issue was due to TLS credentials from CLI flags not being properly propagated to the underlying tiflow server. The changes ensure that security configurations are correctly initialized and passed, thereby restoring secure communication capabilities and enhancing the system's robustness when TLS is enabled.

Highlights

• TLS Credential Propagation Fix: Resolved an issue where TLS credentials provided via CLI flags (--ca, --cert, --key) were not correctly passed to the tiflow server when TiCDC operates in old architecture mode. This previously caused connection failures to TLS-enabled PD clusters.
• Root Cause Identified: The problem stemmed from o.serverConfig.Security not being populated from CLI flags before marshaling o.serverConfig to JSON. Consequently, tiflow's complete() function would overwrite any potential credentials with an empty Security struct.
• Implementation Details: The fix involves explicitly calling o.getCredential() to populate o.serverConfig.Security with the correct TLS information before the configuration is marshaled to JSON. Additionally, redundant assignments of CaPath, CertPath, KeyPath, and AllowedCertCN to oldOptions were removed, as these are now handled within ServerConfig.Security.
• New Unit Tests: A new test file server_test.go has been added, including TestRunTiFlowServerPopulatesSecurityConfig to verify the correct transfer and preservation of TLS credentials during JSON marshaling, along with additional tests for the getCredential function and default security initialization.

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[gemini-code-assist]

Code Review

This pull request effectively resolves the issue of TLS credentials not being passed to tiflow in the old architecture mode. The approach of populating serverConfig.Security before marshaling is correct and directly addresses the root cause. The removal of now-redundant code and the addition of comprehensive unit tests are great improvements. I have one suggestion to refactor the new tests for better maintainability, but overall this is a solid contribution.

[wlwilliamx]

/check-issue-triage-complete

[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: wk989898, wlwilliamx

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Details

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• OWNERS [wk989898,wlwilliamx]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-12-23 03:05:43.440729173 +0000 UTC m=+2133488.254506755: ☑️ agreed by wlwilliamx.
• 2025-12-23 13:36:19.753096926 +0000 UTC m=+2171324.566874498: ☑️ agreed by wk989898.

[wk989898]

@dumanshu Please run make fmt to pass the test

[dumanshu]

/retest-required

[ti-chi-bot]

@dumanshu: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

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In response to this:

/retest-required

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[dumanshu]

@wk989898 Done - ran make fmt and pushed the fix. Could you please run /ok-to-test to trigger CI? Thanks!

[wlwilliamx]

Our CI resource pool has been quite strained these past few days, so CIs are frequently aborted. If this happens, just run /retest again after a while.

[wlwilliamx]

/retest

[dumanshu]

/retest

[ti-chi-bot]

@dumanshu: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

Details

In response to this:

/retest

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[dumanshu]

/test all

[ti-chi-bot]

@dumanshu: Cannot trigger testing until a trusted user reviews the PR and leaves an /ok-to-test message.

Details

In response to this:

/test all

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[dumanshu]

@wlwilliamx - can you help with /ok-to-test as per #3720 (comment) ?

[wk989898]

/ok-to-test

[wk989898]

/retest