feat(dag-w3s-link): proxy post requests

src/index.js

@@ -7,7 +7,7 @@ import {
   composeMiddleware
 } from '@web3-storage/gateway-lib/middleware'
 import { HttpError } from '@web3-storage/gateway-lib/util'
-import { withDenylist, withCdnCache } from './middleware.js'
+import { withDenylist, withCdnCache, withPostProxy } from './middleware.js'
 
 /**
  * @typedef {import('./bindings').Environment} Environment
@@ -29,7 +29,8 @@ export default {
       withContext,
       withParsedIpfsUrl,
       withDenylist,
-      withCdnCache
+      withCdnCache,
+      withPostProxy
     )
     return middleware(handler)(request, env, ctx)
   }

src/middleware.js

@@ -75,3 +75,22 @@ export function withCdnCache (handler) {
     return response
   }
 }
+
+/**
+ * Middleware to proxy all POST requests to the UCANTO Server defined in the environment.
+ *
+ * @type {import('@web3-storage/gateway-lib').Middleware<IpfsUrlContext, IpfsUrlContext, Environment>}
+ */
+export function withPostProxy (handler) {
+  return async (request, env, ctx) => {
+    if (request.method === 'POST') {
+      const originRequest = new Request(request)
+      const url = new URL(request.url)
+      const targetUrl = `https://${env.GATEWAY_URL}/${url.pathname}`
+      const response = await fetch(targetUrl, originRequest)
+      return response
+    }
+
+    return handler(request, env, ctx)
+  }
+}