Make Lightning S3 use force-path-style=true by default (#903)

[ti-srebot]

cherry-pick #903 to release-5.0
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# In br repo:
git pr https://github.com/pingcap/br/pull/923

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---

What problem does this PR solve?

Lightning is different from BR and Dumpling that force-path-style is false by default. This is because both BR and Dumpling reads the storage URL through (*BackendOptions).ParseFromFlags which sets ForcePathStyle to true:

br/pkg/storage/s3.go

Line 203 in 0b223bc

options.ForcePathStyle = true

but such adjustment is absent from Lightning.

What is changed and how it works?

We set the default ForcePathStyle to true inside storage.ParseBackend so Lightning, starting with the default backend options, will also use force-path-style=true by default.

Also fixed the unit tests on Windows.

Check List

Tests

• Unit test

Code changes

Side effects

• Breaking backward compatibility
  • Lightning uses force-path-style=true by default, instead of force-path-style=false.

Related changes

Release Note

• Then importing from S3, Lightning now uses force-path-style=true by default, aligning with BR and Dumpling. To use the virtual host addressing style, explicitly set the force-path-style option like:

  ./tidb-lightning -d 's3://bucket/path?force-path-style=0&...'

[kennytm]

/lgtm

[overvenus]

/lgtm

[ti-chi-bot]

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• overvenus

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[overvenus]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Details

Commit hash: 0f2b6c2