RAGFlow go API server (#13240)

# RAGFlow Go Implementation Plan 🚀

This repository tracks the progress of porting RAGFlow to Go. We'll
implement core features and provide performance comparisons between
Python and Go versions.

## Implementation Checklist

- [x] User Management APIs
- [x] Dataset Management Operations
- [x] Retrieval Test
- [x] Chat Management Operations
- [x] Infinity Go SDK

---------

Signed-off-by: Jin Hai <haijin.chn@gmail.com>
Co-authored-by: Yingfeng Zhang <yingfeng.zhang@gmail.com>

internal/cli/README.md

@@ -0,0 +1,87 @@
+# RAGFlow CLI (Go Version)
+
+This is the Go implementation of the RAGFlow command-line interface, compatible with the Python version's syntax.
+
+## Features
+
+- Interactive mode only
+- Full compatibility with Python CLI syntax
+- Recursive descent parser for SQL-like commands
+- Support for all major commands:
+  - User management: LOGIN, REGISTER, CREATE USER, DROP USER, LIST USERS, etc.
+  - Service management: LIST SERVICES, SHOW SERVICE, STARTUP/SHUTDOWN/RESTART SERVICE
+  - Role management: CREATE ROLE, DROP ROLE, LIST ROLES, GRANT/REVOKE PERMISSION
+  - Dataset management: CREATE DATASET, DROP DATASET, LIST DATASETS
+  - Model management: SET/RESET DEFAULT LLM/VLM/EMBEDDING/etc.
+  - And more...
+
+## Usage
+
+Build and run:
+
+```bash
+go build -o ragflow_cli ./cmd/ragflow_cli.go
+./ragflow_cli
+```
+
+## Architecture
+
+```
+internal/cli/
+├── cli.go           # Main CLI loop and interaction
+├── parser/          # Command parser package
+│   ├── types.go     # Token and Command types
+│   ├── lexer.go     # Lexical analyzer
+│   └── parser.go    # Recursive descent parser
+```
+
+## Command Examples
+
+```sql
+-- Authentication
+LOGIN USER 'admin@example.com';
+
+-- User management
+REGISTER USER 'john' AS 'John Doe' PASSWORD 'secret';
+CREATE USER 'jane' 'password123';
+DROP USER 'jane';
+LIST USERS;
+SHOW USER 'john';
+
+-- Service management
+LIST SERVICES;
+SHOW SERVICE 1;
+STARTUP SERVICE 1;
+SHUTDOWN SERVICE 1;
+RESTART SERVICE 1;
+PING;
+
+-- Role management
+CREATE ROLE admin DESCRIPTION 'Administrator role';
+LIST ROLES;
+GRANT read,write ON datasets TO ROLE admin;
+
+-- Dataset management
+CREATE DATASET 'my_dataset' WITH EMBEDDING 'text-embedding-ada-002' PARSER 'naive';
+LIST DATASETS;
+DROP DATASET 'my_dataset';
+
+-- Model configuration
+SET DEFAULT LLM 'gpt-4';
+SET DEFAULT EMBEDDING 'text-embedding-ada-002';
+RESET DEFAULT LLM;
+
+-- Meta commands
+\?          -- Show help
+\q          -- Quit
+\c          -- Clear screen
+```
+
+## Parser Implementation
+
+The parser uses a hand-written recursive descent approach instead of go-yacc for:
+- Better control over error messages
+- Easier to extend and maintain
+- No code generation step required
+
+The parser structure follows the grammar defined in the Python version, ensuring full syntax compatibility.