EAI-7043: fix UUID-based AIM routing via Lua filter#764
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johnl-amd merged 5 commits intoJun 25, 2026
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…is present When x-ai-eg-backend is set (from body or as a direct header), x-ai-eg-model is intentionally skipped. This prevents model-name fallback rules in other HTTPRoutes from matching — Envoy Gateway maintains per-HTTPRoute ordering so an older route's model-name rule fires before a newer route's UUID rule when both have equal specificity. Without x-ai-eg-model, only the UUID rule and catch-all rules remain; the UUID rule (2 conditions) beats catch-all (0 conditions) by specificity regardless of creation order.
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Jun 25, 2026
merge main to get #764 into RC branch
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Summary
set-model-header-from-body) now skips settingx-ai-eg-modelwhen abackendUUID is present in the request body or headers, so model-name fallback rules in other HTTPRoutes cannot match. The UUID rule (Host +x-ai-eg-backend) wins by specificity over catch-all rules regardless of HTTPRoute creation order.x-ai-eg-model-logheader, always set from the body'smodelfield, so the access log retains model attribution for both UUID-routed and model-name-routed requests.x-ai-eg-model-loginstead ofx-ai-eg-model.Root cause
Envoy Gateway merges HTTPRoute rules maintaining per-route creation-timestamp ordering, not global specificity. Two rules with equal header-match counts from different HTTPRoutes — the older route always wins. When two AIMs serve the same model, the first-created route's model-name rule would always win, routing to the wrong AIM regardless of the
x-ai-eg-backendheader.Test plan
"backend": "<uuid>"in the body; verifybackendClusterin access log shows the correct AIM's HTTPRoute rulemodelfield in access log is still populated for UUID requestsbackendfield) still works for standard OpenAI clients