grpc-web

Description

The grpc-web Plugin is a proxy Plugin that can process gRPC Web requests from JavaScript clients to a gRPC service.

Attributes

Name	Type	Required	Default	Description
cors_allow_headers	string	False	"content-type,x-grpc-web,x-user-agent"	Headers in the request allowed when accessing a cross-origin resource. Use , to add multiple headers.

Enable Plugin

You can enable the grpc-web Plugin on a specific Route as shown below:

note

You can fetch the admin_key from config.yaml and save to an environment variable with the following command:

admin_key=$(yq '.deployment.admin.admin_key[0].key' conf/config.yaml | sed 's/"//g')

curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri":"/grpc/web/*",
    "plugins":{
        "grpc-web":{}
    },
    "upstream":{
        "scheme":"grpc",
        "type":"roundrobin",
        "nodes":{
            "127.0.0.1:1980":1
        }
    }
}'

IMPORTANT

While using the grpc-web Plugin, always use a prefix matching pattern (/*, /grpc/example/*) for matching Routes. This is because the gRPC Web client passes the package name, the service interface name, the method name and other information in the proto in the URI. For example, /path/a6.RouteService/Insert.

So, when absolute matching is used, the Plugin would not be hit and the information from the proto would not be extracted.

Example usage

Refer to gRPC-Web Client Runtime Library or Apache APISIX gRPC Web Test Framework to learn how to setup your web client.

Once you have your gRPC Web client running, you can make a request to APISIX from the browser or through Node.js.

note

The supported request methods are POST and OPTIONS. See CORS support.

The supported Content-Type includes application/grpc-web, application/grpc-web-text, application/grpc-web+proto, and application/grpc-web-text+proto. See Protocol differences vs gRPC over HTTP2.

Delete Plugin

To remove the grpc-web Plugin, you can delete the corresponding JSON configuration from the Plugin configuration. APISIX will automatically reload and you do not have to restart for this to take effect.

curl http://127.0.0.1:9180/apisix/admin/routes/1 -H "X-API-KEY: $admin_key" -X PUT -d '
{
    "uri":"/grpc/web/*",
    "plugins":{},
    "upstream":{
        "scheme":"grpc",
        "type":"roundrobin",
        "nodes":{
            "127.0.0.1:1980":1
        }
    }
}'