fix: add async lock to list_namespaces cache#52
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The shared _namespace_cache dict is accessed without a lock. When multiple MCP tool calls invoke list_namespaces() concurrently and the cache expires, duplicate K8s API calls are made and the cache can be written inconsistently. Added double-checked locking with asyncio.Lock(): fast path reads without lock, slow path (cache miss) acquires lock and re-checks before fetching. Closes #44
olegbet
approved these changes
Jun 22, 2026
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Problem
list_namespaces()accesses the shared_namespace_cachedict without any lock. Concurrent MCP tool calls during cache expiry cause duplicate K8s API calls and potential inconsistent cache state (TOCTOU race).Fix
Added
_namespace_cache_lock = asyncio.Lock()with double-checked locking:Testing
Verified with MCP Inspector:
list_namespacesreturns correct namespace list.Closes #44