log_backup: Adapt for log backup encrypting

[YuJuncen]

What is changed and how it works?

Issue Number: Close #15083

What's Changed:

Allows log backup to read the encryption config and use it to encrypt the local files.

Related changes

• PR to update pingcap/docs/pingcap/docs-cn:
• Need to cherry-pick to the release branch

Check List

Tests

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

Side effects

• Performance regression: Consumes more CPU
• Performance regression: Consumes more Memory
• Breaking backward compatibility

Release note

Now, temporary files generated by log backup will be encrypted if encryption enabled.

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• 3pointer
• Leavrth

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by submitting an approval review.
Reviewer can cancel approval by submitting a request changes review.

[YuJuncen]

/test

[ti-chi-bot]

@YuJuncen: The /test command needs one or more targets.
The following commands are available to trigger required jobs:

• /test pull-unit-test

Use /test all to run all jobs.

In response to this:

/test

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[YuJuncen]

/test pull-unit-test

[ti-chi-bot]

@YuJuncen: The following test failed, say /retest to rerun all failed tests or /retest-required to rerun all mandatory failed tests:

Test name	Commit	Details	Required	Rerun command
pull-unit-test	287be90	link	true	/test pull-unit-test

Full PR test history. Your PR dashboard.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.