replayer: support to load directories dynamically

[YangKeao]

What problem does this PR solve?

Issue Number: close #968

Problem Summary:

What is changed and how it works:

1. Add three flags: "dynamic-input", "replayer-count" and "replayer-index". The meaning of input has a little change.
2. A new struct DirWatcher is used to walk the folder and create decoder dynamically.

Limitation: This PR only supports to have a single input for dynamic-input. It's indeed not difficult to support but we can make it simpler (to develop and to test) with this limitation. I think it can still cover the current scenario.

You can run the S3 tests locally with minio:

docker run -d --rm \
  -p 9000:9000 \
  -p 9001:9001 \
  --name minio-test \
  -e "MINIO_ROOT_USER=minioadmin" \
  -e "MINIO_ROOT_PASSWORD=minioadmin" \
  minio/minio server /data --console-address ":9001"

S3_URL_FOR_TEST="s3://test-bucket?force-path-style=true&endpoint=http://127.0.0.1:9000&access-key=minioadmin&secret-access-key=minioadmin&provider=minio" go test -timeout 30s -tags intest,enterprise, -run ^TestS3DirWatcherWithRealS3$ github.com/pingcap/tiproxy/pkg/sqlreplay/store
S3_URL_FOR_TEST="s3://test-bucket?force-path-style=true&endpoint=http://127.0.0.1:9000&access-key=minioadmin&secret-access-key=minioadmin&provider=minio" go test -timeout 30s -tags intest,enterprise, -run ^TestDynamicInput$ github.com/pingcap/tiproxy/pkg/sqlreplay/replay

Check List

Tests

• Unit test
• Integration test
• Manual test (add detailed scripts or steps below)
• No code

Notable changes

• Has configuration change
• Has HTTP API interfaces change
• Has tiproxyctl change
• Other user behavior changes

Release note

Please refer to Release Notes Language Style Guide to write a quality release note.

None

[codecov-commenter]

Codecov Report

❌ Patch coverage is 63.54839% with 113 lines in your changes missing coverage. Please review.
⚠️ Please upload report for BASE (main@70a6283). Learn more about missing BASE report.

Files with missing lines	Patch %	Lines
pkg/sqlreplay/replay/replay.go	59.37%	47 Missing and 18 partials ⚠️
pkg/sqlreplay/store/dir_watcher.go	72.27%	19 Missing and 9 partials ⚠️
pkg/server/api/traffic.go	6.66%	12 Missing and 2 partials ⚠️
cmd/replayer/main.go	0.00%	6 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #973   +/-   ##
=======================================
  Coverage        ?   67.46%           
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  Files           ?      137           
  Lines           ?    13885           
  Branches        ?        0           
=======================================
  Hits            ?     9367           
  Misses          ?     3850           
  Partials        ?      668           

Flag	Coverage Δ
unit	67.46% <63.54%> (?)

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[ti-chi-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: djshow832

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• OWNERS [djshow832]

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[ti-chi-bot]

[LGTM Timeline notifier]

Timeline:

• 2025-11-07 09:48:40.503899061 +0000 UTC m=+436369.946928930: ☑️ agreed by djshow832.