Add support for success_action_status and success_action_redirect in POST object uploads

[Copilot]

Implements success_action_status and success_action_redirect form fields for S3 POST object uploads per AWS S3 REST API spec.

Changes

Code Generation:

• Updated codegen/src/v1/ops.rs to generate code for extracting and validating success_action_status and success_action_redirect from multipart forms
• Generates validation logic (only accepts 200, 201, 204 for status)
• Generates code to call helper functions for response handling

New Modules:

• crates/s3s/src/ops/post_object.rs: Helper functions for success_action handling
  • handle_success_action_redirect: Returns 303 with Location header + query params
  • handle_success_action_status: Returns specified status with optional XML body
• crates/s3s/src/dto/post_response.rs: PostResponse DTO with XML serialization

Request handling:

• Added success_action_status and success_action_redirect fields to S3Extensions
• Extract and validate fields during multipart form deserialization
  • success_action_status: Only accepts 200, 201, or 204
  • success_action_redirect: Stored as-is for response handling

Response modification in PutObject:

• success_action_redirect takes precedence: returns 303 with Location header containing redirect URL + query params (bucket, key, etag)
• success_action_status:
  • 200/201: XML PostResponse body with Location, Bucket, Key, ETag (using proper XML serialization)
  • 204: Empty body
  • Default (no field): Standard PutObject response unchanged

Security:

• URL encoding for redirect query parameters via urlencoding crate
• XML escaping via quick-xml serialization infrastructure

Applied to both standard and MinIO variants via code generation.

Related

rustfs/rustfs#1073

Original prompt

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This section details on the original issue you should resolve

<issue_title>Missing support for success_action_status and success_action_redirect in S3 POST uploads</issue_title>
<issue_description>https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectPOST.html

Related:

• Missing support for success_action_status and success_action_redirect in S3 POST uploads rustfs/rustfs#1073</issue_description>

<agent_instructions>Try to fix this issue. Run CI checks before committing changes.</agent_instructions>

Comments on the Issue (you are @copilot in this section)

• Fixes Missing support for success_action_status and success_action_redirect in S3 POST uploads #425

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💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

[Nugine]

@copilot

1. Update the codegen to change generated files. Do not modify them directly.
2. Try to build response by XML serialization. Do not build manually.
3. Run CI format and checks.

[Copilot]

@copilot

1. Update the codegen to change generated files. Do not modify them directly.
2. Try to build response by XML serialization. Do not build manually.
   ...

Refactored as requested in commit f227416:

1. ✅ Updated codegen instead of modifying generated files directly
2. ✅ Used XML serialization infrastructure (created PostResponse DTO with proper Serialize impl)
3. ✅ All CI checks pass (fmt, clippy, tests)

The implementation now:

• Generates success_action handling code via codegen/src/v1/ops.rs
• Uses PostResponse DTO with proper XML serialization (no manual string building)
• Keeps response handling logic in post_object.rs module (similar to get_object.rs)