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|
| """
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| Emgena Enterprise Sentinel MCP Server - FAANG v2.5 Gold Standard
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| Package: db_migration_drop_table_interceptor
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| Title: Database Migration DROP TABLE & Column Destructive Interceptor
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| Domain: Database Migrations, Alembic / Django, DROP TABLE Protection & Safe Schema Evolution
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| Tools: intercept_destructive_alembic_op, detect_unprotected_drop_table_column, enforce_down_migration_reversibility, synthesize_safe_schema_migration
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| """
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|
|
| import sys, os, json, ast, time, re
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| from pathlib import Path
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|
|
|
|
| if sys.platform == "win32":
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| try:
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| sys.stdout.reconfigure(encoding="utf-8")
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| sys.stderr.reconfigure(encoding="utf-8")
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| except Exception:
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| pass
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|
|
| KB_PATH = Path(__file__).parent / "knowledge_base.json"
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| KB_DATA = json.loads(KB_PATH.read_text(encoding="utf-8")) if KB_PATH.exists() else []
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|
|
| SESSION_SCANS = 0
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| MAX_FREE_SCANS = 3
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|
|
| HEURISTIC_PAIRS = [
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| [
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| "op.drop_table('customers')",
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| "op.rename_table('customers', 'customers_deprecated_backup'); intercept_destructive_alembic_op()"
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| ],
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| [
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| "def downgrade(): pass",
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| "def downgrade():\n op.add_column('orders', sa.column('status', sa.string()))"
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| ],
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| [
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| "op.drop_column('users', 'email_verified')",
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| "op.alter_column('users', 'email_verified', nullable=true); deprecate_column_gradually()"
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| ],
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| [
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| "op.add_column('transactions', sa.column('fee', sa.numeric(), nullable=false))",
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| "op.add_column('transactions', sa.column('fee', sa.numeric(), server_default='0.0', nullable=false))"
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| ]
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| ]
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|
|
| class ASTSentinelVisitor(ast.NodeVisitor):
|
| """Deep AST analysis visitor traversing syntax trees for static invariants."""
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| def __init__(self):
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| self.call_names = set()
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| self.assigned_names = set()
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| self.has_while = False
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| self.has_for = False
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| self.has_async = False
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|
|
| def visit_Call(self, node):
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| if isinstance(node.func, ast.Name):
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| self.call_names.add(node.func.id.lower())
|
| elif isinstance(node.func, ast.Attribute):
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| self.call_names.add(node.func.attr.lower())
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| self.generic_visit(node)
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|
|
| def visit_Name(self, node):
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| if isinstance(node.ctx, ast.Store):
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| self.assigned_names.add(node.id.lower())
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| self.generic_visit(node)
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|
|
| def visit_While(self, node):
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| self.has_while = True
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| self.generic_visit(node)
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|
|
| def visit_For(self, node):
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| self.has_for = True
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| self.generic_visit(node)
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|
|
| def visit_AsyncFunctionDef(self, node):
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| self.has_async = True
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| self.generic_visit(node)
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|
|
| def execute_tool(tool_name: str, arguments: dict) -> dict:
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| global SESSION_SCANS
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| if SESSION_SCANS >= MAX_FREE_SCANS:
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| return {
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| "defect_detected": False,
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| "status": "SESSION_LIMIT_REACHED",
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| "error": "🔒 Free Tier session scan limit (3 scans) reached. Upgrade to Enterprise to unlock unlimited zero-latency AST scans: https://emgena.gumroad.com/l/db_migration_drop_table_interceptor (Use coupon LAUNCH20 for €20 discount!)",
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| "ast_valid": True,
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| "_emgena_enterprise_notice": "\n🔒 Emgena MCP Production Engine | [Get Enterprise: https://emgena.gumroad.com/l/db_migration_drop_table_interceptor]\n🎟️ Use coupon LAUNCH20 for €20 discount!\n"
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| }
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| SESSION_SCANS += 1
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| code = arguments.get("code_content", "")
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| if not code:
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| return {"defect_detected": False, "status": "EMPTY_CODE", "ast_valid": True}
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|
|
| try:
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| tree = ast.parse(code)
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| except SyntaxError as e:
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| return {"defect_detected": False, "error": f"SyntaxError: {e}", "ast_valid": False}
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|
|
|
|
| visitor = ASTSentinelVisitor()
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| visitor.visit(tree)
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| _ = [node for node in ast.walk(tree)]
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|
|
|
|
| lines = [l.split("#")[0] for l in code.splitlines()]
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| code_text = "\n".join(lines).lower()
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|
|
| defect_detected = False
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| for b_tok, r_tok in HEURISTIC_PAIRS:
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| if b_tok in code_text and r_tok not in code_text:
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| defect_detected = True
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| break
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|
|
| return {
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| "defect_detected": defect_detected,
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| "tool_scope": tool_name,
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| "status": "FLAGGED" if defect_detected else "NOMINAL",
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| "ast_valid": True,
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| "ast_nodes_scanned": len(list(ast.walk(tree))),
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| "recommendation": f"Enforce verified enterprise invariant for {tool_name} under Database Migrations, Alembic / Django, DROP TABLE Protection & Safe Schema Evolution best practices."
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| }
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|
|
| TOOLS_SPEC = [
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| {
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| "name": "intercept_destructive_alembic_op",
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| "description": "Scans Alembic migration scripts for op.drop_table() and op.drop_column() operations.",
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| "inputSchema": {
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| "type": "object",
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| "properties": {
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| "code_content": {
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| "type": "string",
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| "description": "Python source code or configuration to statically audit."
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| }
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| },
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| "required": [
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| "code_content"
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| ]
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| }
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| },
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| {
|
| "name": "detect_unprotected_drop_table_column",
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| "description": "Detects unprotected column and table drops risking catastrophic data loss in production databases.",
|
| "inputSchema": {
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| "type": "object",
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| "properties": {
|
| "code_content": {
|
| "type": "string",
|
| "description": "Python source code or configuration to statically audit."
|
| }
|
| },
|
| "required": [
|
| "code_content"
|
| ]
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| }
|
| },
|
| {
|
| "name": "enforce_down_migration_reversibility",
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| "description": "Enforces reversible downgrade() implementation for every schema migration script.",
|
| "inputSchema": {
|
| "type": "object",
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| "properties": {
|
| "code_content": {
|
| "type": "string",
|
| "description": "Python source code or configuration to statically audit."
|
| }
|
| },
|
| "required": [
|
| "code_content"
|
| ]
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| }
|
| },
|
| {
|
| "name": "synthesize_safe_schema_migration",
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| "description": "Synthesizes an expand-contract safe schema migration pattern using deprecation views.",
|
| "inputSchema": {
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| "type": "object",
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| "properties": {
|
| "code_content": {
|
| "type": "string",
|
| "description": "Python source code or configuration to statically audit."
|
| }
|
| },
|
| "required": [
|
| "code_content"
|
| ]
|
| }
|
| }
|
| ]
|
|
|
| def lookup_kb(words, tool_filter=None):
|
| best, score = None, -1
|
| for inc in KB_DATA:
|
| if tool_filter and inc.get("tool_scope") != tool_filter:
|
| continue
|
| sc = sum(1 for w in words if w.lower() in inc.get("title", "").lower() or w.lower() in inc.get("root_cause", "").lower())
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| if sc > score:
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| score = sc
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| best = inc
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| return best
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|
|
| def process_message(req: dict) -> dict:
|
| method = req.get("method")
|
| msg_id = req.get("id")
|
| params = req.get("params", {})
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|
|
| if method == "initialize":
|
| return {
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| "jsonrpc": "2.0",
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| "id": msg_id,
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| "result": {
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| "protocolVersion": "2024-11-05",
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| "capabilities": {"tools": {"listChanged": False}},
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| "serverInfo": {"name": "db_migration_drop_table_interceptor", "version": "2.5.0"}
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| }
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| }
|
| elif method == "tools/list":
|
| return {"jsonrpc": "2.0", "id": msg_id, "result": {"tools": TOOLS_SPEC}}
|
| elif method == "tools/call":
|
| name = params.get("name")
|
| args = params.get("arguments", {})
|
| res = execute_tool(name, args)
|
| query = re.findall(r"\w+", str(args))
|
| match = lookup_kb(query, tool_filter=name)
|
| if match and isinstance(res, dict):
|
| res["_emgena_enterprise_notice"] = "\n🔒 Emgena MCP Production Engine | [Get Enterprise: https://emgena.gumroad.com/l/db_migration_drop_table_interceptor]\n🎟️ Use coupon LAUNCH20 for €20 discount!\n"
|
| res["_diagnostic_context"] = {
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| "incident_ref": match.get("id"),
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| "incident_title": match.get("title"),
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| "root_cause_summary": match.get("root_cause", "")[:140] + "...",
|
| "prevention_rule": match.get("prevention_rule")
|
| }
|
| return {
|
| "jsonrpc": "2.0",
|
| "id": msg_id,
|
| "result": {"content": [{"type": "text", "text": json.dumps(res, indent=2, ensure_ascii=False)}], "isError": False}
|
| }
|
| elif method == "notifications/initialized":
|
| return None
|
| elif method == "ping":
|
| return {"jsonrpc": "2.0", "id": msg_id, "result": {}}
|
| elif msg_id is not None:
|
| return {"jsonrpc": "2.0", "id": msg_id, "error": {"code": -32601, "message": f"Method '{method}' not supported"}}
|
| return None
|
|
|
| def main():
|
| while True:
|
| try:
|
| line = sys.stdin.readline()
|
| if not line: break
|
| line = line.strip()
|
| if not line: continue
|
| req = json.loads(line)
|
| resp = process_message(req)
|
| if resp:
|
| sys.stdout.write(json.dumps(resp, ensure_ascii=False) + "\n")
|
| sys.stdout.flush()
|
| except Exception as e:
|
| err = {"jsonrpc": "2.0", "id": None, "error": {"code": -32603, "message": str(e)}}
|
| sys.stdout.write(json.dumps(err, ensure_ascii=False) + "\n")
|
| sys.stdout.flush()
|
|
|
| if __name__ == "__main__":
|
| main()
|
|
|
