Fix the issue where AI route fallback does not work when using Bedrock. (#2653)

plugins/wasm-go/extensions/ai-proxy/main.go

@@ -97,6 +97,9 @@ func initContext(ctx wrapper.HttpContext) {
 		value, _ := proxywasm.GetHttpRequestHeader(header)
 		ctx.SetContext(ctxKey, value)
 	}
+	for _, originHeader := range headerToOriginalHeaderMapping {
+		proxywasm.RemoveHttpRequestHeader(originHeader)
+	}
 }
 
 func saveContextsToHeaders(ctx wrapper.HttpContext) {
@@ -127,6 +130,9 @@ func onHttpRequestHeader(ctx wrapper.HttpContext, pluginConfig config.PluginConf
 
 	log.Debugf("[onHttpRequestHeader] provider=%s", activeProvider.GetProviderType())
 
+	// Disable the route re-calculation since the plugin may modify some headers related to the chosen route.
+	ctx.DisableReroute()
+
 	initContext(ctx)
 
 	rawPath := ctx.Path()
@@ -156,8 +162,6 @@ func onHttpRequestHeader(ctx wrapper.HttpContext, pluginConfig config.PluginConf
 	}
 
 	ctx.SetContext(provider.CtxKeyApiName, apiName)
-	// Disable the route re-calculation since the plugin may modify some headers related to the chosen route.
-	ctx.DisableReroute()
 
 	// Always remove the Accept-Encoding header to prevent the LLM from sending compressed responses,
 	// allowing plugins to inspect or modify the response correctly