Basic NJS module to extract model name

.nvmrc

@@ -1 +1 @@
-22
+24

Makefile

@@ -33,7 +33,7 @@ GEN_CRD_API_REFERENCE_DOCS_VERSION = v0.3.0
 # renovate: datasource=go depName=sigs.k8s.io/controller-tools
 CONTROLLER_TOOLS_VERSION = v0.19.0
 # renovate: datasource=docker depName=node
-NODE_VERSION = 22
+NODE_VERSION = 24
 # renovate: datasource=docker depName=quay.io/helmpack/chart-testing
 CHART_TESTING_VERSION = v3.13.0
 # renovate: datasource=github-tags depName=dadav/helm-schema

build/Dockerfile.nginx

@@ -23,7 +23,7 @@ RUN apk add --no-cache bash \
     && ln -sf /dev/stderr /var/log/nginx/error.log
 
 COPY build/entrypoint.sh /agent/entrypoint.sh
-COPY ${NJS_DIR}/httpmatches.js /usr/lib/nginx/modules/njs/httpmatches.js
+COPY ${NJS_DIR}/ /usr/lib/nginx/modules/njs/
 COPY ${NGINX_CONF_DIR}/nginx.conf /etc/nginx/nginx.conf
 COPY ${NGINX_CONF_DIR}/grpc-error-locations.conf /etc/nginx/grpc-error-locations.conf
 COPY ${NGINX_CONF_DIR}/grpc-error-pages.conf /etc/nginx/grpc-error-pages.conf

build/Dockerfile.nginxplus

@@ -29,7 +29,7 @@ RUN apk add --no-cache bash \
     && ln -sf /dev/stderr /var/log/nginx/error.log
 
 COPY build/entrypoint.sh /agent/entrypoint.sh
-COPY ${NJS_DIR}/httpmatches.js /usr/lib/nginx/modules/njs/httpmatches.js
+COPY ${NJS_DIR}/ /usr/lib/nginx/modules/njs/
 COPY ${NGINX_CONF_DIR}/nginx-plus.conf /etc/nginx/nginx.conf
 COPY ${NGINX_CONF_DIR}/grpc-error-locations.conf /etc/nginx/grpc-error-locations.conf
 COPY ${NGINX_CONF_DIR}/grpc-error-pages.conf /etc/nginx/grpc-error-pages.conf

internal/controller/nginx/conf/nginx-plus.conf

@@ -13,6 +13,7 @@ http {
   include /etc/nginx/conf.d/*.conf;
   include /etc/nginx/mime.types;
   js_import /usr/lib/nginx/modules/njs/httpmatches.js;
+  js_import /usr/lib/nginx/modules/njs/epp.js;
 
   default_type application/octet-stream;
 

internal/controller/nginx/conf/nginx.conf

@@ -13,6 +13,7 @@ http {
   include /etc/nginx/conf.d/*.conf;
   include /etc/nginx/mime.types;
   js_import /usr/lib/nginx/modules/njs/httpmatches.js;
+  js_import /usr/lib/nginx/modules/njs/epp.js;
 
   default_type application/octet-stream;
 

internal/controller/nginx/modules/README.md

@@ -22,6 +22,7 @@ dependencies.
 
 - [httpmatches](./src/httpmatches.js): a location handler for HTTP requests. It redirects requests to an internal
   location block based on the request's headers, arguments, and method.
+- [epp](./src/epp.js): handles communication with the EndpointPicker (EPP) component. This is for acquiring a specific AI endpoint to route client traffic to when using the Gateway API Inference Extension.
 
 ### Helpful Resources for Module Development
 

internal/controller/nginx/modules/src/epp.js

@@ -0,0 +1,29 @@
+// This file contains the methods to get an AI workload endpoint from the EndpointPicker (EPP).
+
+// TODO (sberman): this module will need to be enhanced to include the following:
+// - function that sends the subrequest to the Go middleware application (to get the endpoint from EPP)
+// - if a user has specified an Exact matching condition for a model name, extract the model name from
+// the request body, and if it matches that condition, set the proper value in the X-Gateway-Model-Name header
+// (based on if we do a redirect or traffic split (see design doc)) in the subrequest. If the client request
+// already has this header set, then I don't think we need to extract the model from the body, just pass
+// through the existing header.
+// I believe we have to use js_content to call the NJS functionality. Because this takes over
+// the request, we will likely have to finish the NJS functionality with an internalRedirect to an internal
+// location that proxy_passes to the chosen endpoint.
+
+// extractModel extracts the model name from the request body.
+function extractModel(r) {
+	try {
+		var body = JSON.parse(r.requestText);
+		if (body && body.model !== undefined) {
+			return String(body.model);
+		}
+	} catch (e) {
+		r.error(`error parsing request body for model name: ${e.message}`);
+		return '';
+	}
+	r.error('request body does not contain model parameter');
+	return '';
+}
+
+export default { extractModel };

internal/controller/nginx/modules/test/epp.test.js

@@ -0,0 +1,52 @@
+import { default as epp } from '../src/epp.js';
+import { expect, describe, it } from 'vitest';
+
+function makeRequest(body) {
+	let r = {
+		// Test mocks
+		error(msg) {
+			r.variables.error = msg;
+		},
+		requestText: body,
+		variables: {},
+	};
+
+	return r;
+}
+
+describe('extractModel', () => {
+	const tests = [
+		{
+			name: 'returns the model value',
+			body: '{"model":"gpt-4"}',
+			model: 'gpt-4',
+			error: undefined,
+		},
+		{
+			name: 'returns empty string if model is missing',
+			body: '{"foo":1}',
+			model: '',
+			error: 'request body does not contain model parameter',
+		},
+		{
+			name: 'returns empty string for invalid JSON',
+			body: 'not-json',
+			model: '',
+			error: `error parsing request body for model name: Unexpected token 'o', "not-json" is not valid JSON`,
+		},
+		{
+			name: 'empty request body',
+			body: '',
+			model: '',
+			error: 'error parsing request body for model name: Unexpected end of JSON input',
+		},
+	];
+
+	tests.forEach((test) => {
+		it(test.name, () => {
+			let r = makeRequest(test.body);
+			expect(epp.extractModel(r)).to.equal(test.model);
+			expect(r.variables.error).to.equal(test.error);
+		});
+	});
+});