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feat(proxy): entry-level URL rewriting via proxy.url_rewrites - #878
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jarvis9443 wants to merge 3 commits into
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feat(proxy): entry-level URL rewriting via proxy.url_rewrites#878jarvis9443 wants to merge 3 commits into
jarvis9443 wants to merge 3 commits into
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An ordered list of {match, rewrite} regex rules applied to every
proxy-listener request before route matching (admin/metrics listeners
unaffected): the first matching rule rewrites the path once — no
cascading — and the request then flows through the normal endpoint
(auth, ACL, quota, metrics labelling) as if the client had sent the
rewritten path. Replacement substitutes the matched portion with
$1/${name} capture-group expansion; the query string is preserved; a
miss leaves the request untouched. Invalid regexes fail startup.
Because axum's Router::layer middleware runs after route matching, the
rewrite gets its pre-routing seat by wrapping the whole router as the
fallback of an outer router; the wrapper is only built when rules are
configured, so the default path pays nothing.
Lets operators map legacy URL shapes onto AISIX endpoints without
client changes — e.g. per-server MCP paths like /mcp-servers/{svc}/mcp
onto the /mcp/{server} endpoint, completing the migration scenario of
api7/AISIX-Cloud#1219 together with the scoped-endpoint PR.Important Review skippedAuto reviews are disabled on base/target branches other than the default branch. Please check the settings in the CodeRabbit UI or the ⚙️ Run configurationConfiguration used: Organization UI Review profile: CHILL Plan: Pro Run ID: You can disable this status message by setting the Use the checkbox below for a quick retry:
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Stacked on #875 (the
/mcp/{server}scoped endpoint); only the top commit is new here.What
Adds
proxy.url_rewrites: an ordered list of entry-level URL rewrite rules applied to every proxy-listener request before route matching (the admin and metrics listeners are unaffected).matchregex matches the request path rewrites it — once, no cascading — and the request then flows through the normal endpoint (auth, ACL, quota, metrics labelling) exactly as if the client had sent the rewritten path. A miss leaves the request untouched.rewritereplaces the matched portion of the path;$1/${name}expand capture groups; the query string is preserved as sent.Config::validate), so a typo surfaces at boot instead of as every legacy request 404ing. A template that assembles an invalid path at runtime logs a warning naming the rule and leaves the request unrewritten.Implementation note: axum's
Router::layermiddleware runs after route matching, so a URI rewritten there could never change which route matches. The rewrite therefore wraps the whole router as the fallback of an outer router, giving it a genuine pre-routing seat.Why
Lets operators map legacy URL shapes onto AISIX endpoints without client changes. The flagship scenario (api7/AISIX-Cloud#1219): clients migrating from gateways that expose one URL per MCP server (
/mcp-servers/{service}/{path}) keep their configured URLs and original tool names — one rule maps the URL onto the/mcp/{server}endpoint from #875, and the whole existing governance chain applies unchanged.Design comparison (per repo rule): mainstream gateways all ship a regex path-rewrite primitive with matched-portion replacement and capture-group templates (route-plugin, per-route rewrite, or middleware forms). Ours differs in placement only — a gateway-global ordered rule list instead of per-route config — because AISIX's routes are fixed built-in endpoints and the layer's purpose is mapping external URL space onto them; first-match-wins order replaces per-route attachment. LiteLLM offers no operator-configurable equivalent (its per-server MCP alias route is an internal fixed rewrite of the same shape), so the APISIX-style rewrite plugins are the reference baseline here.
Rewriting cannot bypass governance: it only re-targets which proxy endpoint serves the request, and every endpoint enforces its own auth/ACL/quota after the rewrite; the admin surface lives on a separate listener the layer never touches.
Tests
crates/aisix-proxy/src/rewrite.rs— unit + router-level: capture groups, matched-portion semantics, named/braced references, query preservation, invalid-path fallback, first-rule-wins through the real router, no-rules passthrough.crates/aisix-core/src/config.rs— config load + invalid-regex boot rejection.tests/e2e/src/cases/url-rewrite-e2e.test.ts— real binary + etcd + real MCP upstream: the full migration scenario (legacy per-server URL + original tool name end to end), generic non-MCP mapping, query survival, miss-passthrough (canonical paths intact, unmatched legacy tails 404).config.example.yaml/config.managed.yamldocument the block. Fixes api7/AISIX-Cloud#1219.