The GraphQL endpoint built its gqlgen server with bare handler.New and
no limits, so a single request with thousands of aliased resolver calls
was parsed, validated, executed, and marshalled in full. Under load this
let an unauthenticated client drive excessive CPU and memory use against
POST /api/connect/v1/graphql and the console and trust endpoints, which
share the same constructor (GHSA-prh2-g8pv-m7p9).
Add configurable guards in the shared gqlutils.NewHandler: a parser
token limit rejects oversized queries at lex time before any execution,
a fixed complexity limit caps field-selection count, an LRU query cache
avoids repeated parsing, and field suggestions are disabled. The limits
flow from a new APIConfig.GraphQL section through server and api config
into all three GraphQL handlers, with PROBOD_API_GRAPHQL_* env vars and
Helm values exposed for per-environment tuning.
Defaults are sized with generous headroom over real traffic: the parser
token limit (15000) and complexity limit (2000) sit far above the
largest legitimate frontend query yet well below the proof-of-concept
flood, so normal usage is unaffected while floods are rejected cheaply.
Signed-off-by: Bryan Frimin <bryan@probo.com>
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