As described in Adding CORS support to
ESP,
you can configure the Extensible Service Proxy
(ESP) to support CORS.
If the ESP options don't provide the CORS support that your
application requires, you can add the CORS options to ESP's configuration file,
nginx.conf.
Adding the CORS options to nginx.conf
To add the CORS options:
Start with a nginx.conf file that contains the configuration required by
Cloud Endpoints. You can start with the sample
nginx.conf,
or if you have already deployed ESP, you can SSH to the ESP container and
copy the nginx.conf file from the /etc/nginx/endpoints/ directory.
Add the CORS options that your application requires to nginx.conf. You can
use the CORS on NGINX example
as a starting point.
Start ESP with the --nginx_config option with the path to the custom
nginx.conf file.
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Hard to understand","hardToUnderstand","thumb-down"],["Incorrect information or sample code","incorrectInformationOrSampleCode","thumb-down"],["Missing the information/samples I need","missingTheInformationSamplesINeed","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-07 UTC."],[[["\u003cp\u003eThe Extensible Service Proxy (ESP) can be configured to support CORS, as described in the documentation about adding CORS support to ESP.\u003c/p\u003e\n"],["\u003cp\u003eIf ESP's default options are insufficient, you can customize CORS support by editing the \u003ccode\u003enginx.conf\u003c/code\u003e configuration file.\u003c/p\u003e\n"],["\u003cp\u003eA sample \u003ccode\u003enginx.conf\u003c/code\u003e file, or an existing one from a deployed ESP container, can serve as the basis for customization.\u003c/p\u003e\n"],["\u003cp\u003eAfter adding your required CORS options to \u003ccode\u003enginx.conf\u003c/code\u003e, ESP must be started with the \u003ccode\u003e--nginx_config\u003c/code\u003e option pointing to this modified file.\u003c/p\u003e\n"]]],[],null,["# Creating a Custom nginx.conf to Support CORS\n\n[OpenAPI](/endpoints/docs/openapi/custom-cors-nginx \"View this page for the Cloud Endpoints OpenAPI docs\") \\| gRPC\n\n\u003cbr /\u003e\n\nAs described in [Adding CORS support to\nESP](/endpoints/docs/grpc/specify-proxy-startup-options#adding_cors_support_to_esp),\nyou can configure the [Extensible Service Proxy\n(ESP)](/endpoints/docs/grpc/glossary#extensible_service_proxy) to support CORS.\nIf the ESP options don't provide the CORS support that your\napplication requires, you can add the CORS options to ESP's configuration file,\n`nginx.conf`.\n\nAdding the CORS options to `nginx.conf`\n---------------------------------------\n\nTo add the CORS options:\n\n1. Start with a `nginx.conf` file that contains the configuration required by\n Cloud Endpoints. You can start with the [sample\n `nginx.conf`](https://github.com/GoogleCloudPlatform/endpoints-samples/blob/master/k8s/nginx.conf),\n or if you have already deployed ESP, you can SSH to the ESP container and\n copy the `nginx.conf` file from the `/etc/nginx/endpoints/` directory.\n\n2. Add the CORS options that your application requires to `nginx.conf`. You can\n use the [CORS on NGINX](https://enable-cors.org/server_nginx.html) example\n as a starting point.\n\n3. Start ESP with the `--nginx_config` option with the path to the custom\n `nginx.conf` file.\n\nWhat's next\n-----------\n\n- Learn about [ESP's startup options](/endpoints/docs/grpc/specify-proxy-startup-options).\n\n- Learn how to [SSH to ESP's container on GKE](/endpoints/docs/grpc/troubleshoot-gke-deployment#checking_configuration_files).\n\n- Learn about [using a custom nginx.conf on GKE](/endpoints/docs/grpc/custom-nginx)."]]
