After #7221, guardrail allowlists built from a path-style provider's declared
model ids (Bedrock, Vertex) stopped working: the raw region/version form was
compared against the parser's canonical id, so the agent config advertised an
empty model list and requests for the allowlisted model were refused.
Make every allowlist compare provider-aware, keyed on the destination
provider's catalog id: the agent config, the policy gate, and the synthesized
proxy allowlists match an entry on both its verbatim and canonical form —
Bedrock's strip only under bedrock_api, Vertex's only under vertex_ai_api,
verbatim everywhere else, so a plain provider's suffixed entries never widen.
The router's claim compare learns the Vertex @version strip.
New e2e, realstore, and unit tests reproduce both regressions and pin the fix.
## Describe your changes
The model-allowlist guardrail was merged into one account-wide union and
enforced flat on every request, ignoring which policy/group/provider
authorised it. With multiple policies — especially a mix of guardrailed
and un-guardrailed ones — this caused:
- **false-allow**: a model allowlisted for one group/provider leaked to
any caller; and
- **false-deny**: an un-guardrailed policy (intended unrestricted) was
blocked by another policy's allowlist.
Enforcement is now policy/group-aware, mirroring `llm_limit_check`:
- **Management (`SelectPolicyForRequest`) is authoritative.** It uses
the request model (already carried in
`CheckLLMPolicyLimitsRequest.model`, previously ignored) to keep only
applicable policies whose guardrails permit the model; no
allowlist-enabled guardrail = unrestricted. Denies
`llm_policy.model_blocked` when policies govern the (provider, groups)
but none permits the model.
- **Proxy `llm_guardrail` becomes a per-provider fail-closed backstop.**
The synthesiser emits an allowlist only for providers every authorising
policy restricts; the middleware keys off the resolved provider id and
keeps unknown-model fail-closed.
Maycon Santos