WC-3584 Add eyeball routing config

Provided via a new optional param binding. When provided, it contains
info about free tier limiting for this account.

Author: matthewdavidrodgers

packages/workers-shared/router-worker/src/configuration.ts

@@ -1,6 +1,8 @@
-import type { RouterConfig } from "../../utils/types";
+import type { EyeballRouterConfig, RouterConfig } from "../../utils/types";
 
-export const applyConfigurationDefaults = (
+type RequiredEyeballRouterConfig = Required<Exclude<EyeballRouterConfig, null>>;
+
+export const applyRouterConfigDefaults = (
 	configuration?: RouterConfig
 ): Required<RouterConfig> => {
 	return {
@@ -15,3 +17,11 @@ export const applyConfigurationDefaults = (
 		},
 	};
 };
+
+export const applyEyeballConfigDefaults = (
+	eyeballConfiguration?: EyeballRouterConfig
+): RequiredEyeballRouterConfig => {
+	return {
+		limitedAssetsOnly: eyeballConfiguration?.limitedAssetsOnly ?? false,
+	};
+};

packages/workers-shared/router-worker/src/worker.ts

@@ -3,9 +3,13 @@ import { PerformanceTimer } from "../../utils/performance";
 import { setupSentry } from "../../utils/sentry";
 import { mockJaegerBinding } from "../../utils/tracing";
 import { Analytics, DISPATCH_TYPE, STATIC_ROUTING_DECISION } from "./analytics";
-import { applyConfigurationDefaults } from "./configuration";
+import {
+	applyEyeballConfigDefaults,
+	applyRouterConfigDefaults,
+} from "./configuration";
 import type AssetWorker from "../../asset-worker";
 import type {
+	EyeballRouterConfig,
 	JaegerTracing,
 	RouterConfig,
 	UnsafePerformanceTimer,
@@ -16,6 +20,7 @@ export interface Env {
 	ASSET_WORKER: Service<AssetWorker>;
 	USER_WORKER: Fetcher;
 	CONFIG: RouterConfig;
+	EYEBALL_CONFIG: EyeballRouterConfig;
 
 	SENTRY_DSN: string;
 	ENVIRONMENT: Environment;
@@ -55,7 +60,8 @@ export default {
 			);
 
 			const hasStaticRouting = env.CONFIG.static_routing !== undefined;
-			const config = applyConfigurationDefaults(env.CONFIG);
+			const config = applyRouterConfigDefaults(env.CONFIG);
+			const eyeballConfig = applyEyeballConfigDefaults(env.EYEBALL_CONFIG);
 
 			const url = new URL(request.url);
 
@@ -77,7 +83,11 @@ export default {
 
 			const maybeSecondRequest = request.clone();
 
-			const routeToUserWorker = async ({ asset }: { asset: "static_routing" | "none" }) => {
+			const routeToUserWorker = async ({
+				asset,
+			}: {
+				asset: "static_routing" | "none";
+			}) => {
 				if (!config.has_user_worker) {
 					throw new Error(
 						"Fetch for user worker without having a user worker binding"
@@ -95,7 +105,11 @@ export default {
 				});
 			};
 
-			const routeToAssets = async ({ asset }: { asset: "static_routing" | "found" | "none" }) => {
+			const routeToAssets = async ({
+				asset,
+			}: {
+				asset: "static_routing" | "found" | "none";
+			}) => {
 				analytics.setData({ dispatchtype: DISPATCH_TYPE.ASSETS });
 				return await env.JAEGER.enterSpan("dispatch_assets", async (span) => {
 					span.setTags({

packages/workers-shared/router-worker/wrangler.jsonc

@@ -25,6 +25,12 @@
 				"type": "param",
 				"param": "routerConfig",
 			},
+			{
+				"name": "EYEBALL_CONFIG",
+				"type": "param",
+				"param": "eyeballRouterConfig",
+				"optional": true,
+			},
 			{
 				"name": "ASSET_WORKER",
 				"type": "internal_assets",

packages/workers-shared/utils/types.ts

@@ -20,6 +20,13 @@ export const RouterConfigSchema = z.object({
 	...InternalConfigSchema.shape,
 });
 
+export const EyeballRouterConfigSchema = z.union([
+	z.object({
+		limitedAssetsOnly: z.boolean().optional(),
+	}),
+	z.null(),
+]);
+
 const MetadataStaticRedirectEntry = z.object({
 	status: z.number(),
 	to: z.string(),
@@ -79,6 +86,7 @@ export const AssetConfigSchema = z.object({
 	...InternalConfigSchema.shape,
 });
 
+export type EyeballRouterConfig = z.infer<typeof EyeballRouterConfigSchema>;
 export type RouterConfig = z.infer<typeof RouterConfigSchema>;
 export type AssetConfig = z.infer<typeof AssetConfigSchema>;