[英]How to add metadata to nodejs grpc call
I'd like to know how to add metadata to a nodejs grpc function call. 我想知道如何将元数据添加到nodejs grpc函数调用中。 I can use channel credentials when making the client with
与客户建立联系时,我可以使用渠道凭证
var client = new proto.Document('some.address:8000',
grpc.credentials.createInsecure()
)
Which are send when using client.Send(doc, callback)
, but the go grpc server looks in the call metadata for identification information which I have to set. 使用
client.Send(doc, callback)
时发送的是哪些,但是go grpc服务器在调用元数据中查找我必须设置的标识信息。 I tried using grpc.credentials.combineChannelCredentials
with the insecure connection and a grpc.Metadata
instance but I can't find the right way to do it. 我尝试将
grpc.credentials.combineChannelCredentials
与不安全的连接和grpc.Metadata
实例一起使用,但是找不到正确的方法。
The error I run into is TypeError: compose's first argument must be a CallCredentials object
. 我遇到的错误是
TypeError: compose's first argument must be a CallCredentials object
。 I tried to follow it down but it goes into c code which loses me, I can't see what javascript type I have to give to comebineChannelCredentials
to achieve what I'm looking for and the docs are a little sparse on how to achieve this. 我试图跟进它,但是它陷入了C代码,这让我
comebineChannelCredentials
了我,我看comebineChannelCredentials
为实现我想要的功能而必须给comebineChannelCredentials
提供什么javascript类型,并且文档对如何实现这一目标有点稀疏。
You can pass metadata directly as an optional argument to a method call. 您可以将元数据直接作为可选参数传递给方法调用。 So, for example, you could do this:
因此,例如,您可以这样做:
var meta = new grpc.Metadata();
meta.add('key', 'value');
client.send(doc, meta, callback);
For sake of completeness I'm going to extend on @murgatroid99 answer. 为了完整起见,我将扩展@ murgatroid99的答案。
In order to attach metadata to a message on the client you can use: 为了将元数据附加到客户端上的消息,您可以使用:
var meta = new grpc.Metadata();
meta.add('key', 'value');
client.send(doc, meta, callback);
On the server side int your RPC method being called, when you want to grab your data you can use: 在服务器端int上,您的RPC方法被调用,当您想要获取数据时,可以使用:
function(call, callback){
var myVals = call.metadata.get("key");
//My vals will be an array, so if you want to grab a single value:
var myVal = myVals[0];
}
I eventually worked it out through introspecting the grpc credentials code and modifying the implementation to expose an inner function. 我最终通过内省grpc凭证代码并修改实现以公开内部功能来解决。 In the
grpc
module in the node_modules
, file grpc/src/node/src/credentials.js
add the line 在
grpc
在模块node_modules
,文件grpc/src/node/src/credentials.js
添加行
exports.CallCredentials = CallCredentials;
after CallCredentials
is imported. 导入
CallCredentials
之后。 Then, in your code, you can write something like 然后,在您的代码中,您可以编写如下内容
var meta = grpc.Metadata();
meta.add('key', 'value');
var extra_creds = grpc.credentials.CallCredentials.createFromPlugin(
function (url, callback) {
callback(null, meta);
}
)
Then use extra_creds
in the client builder 然后在客户端构建器中使用
extra_creds
var creds = grpc.credentials.combineChannelCredentials(
grpc.credentials.createSsl(),
extra_creds,
)
Now you can make your client 现在您可以使您的客户
var client = new proto.Document(
'some.address:8000',
creds,
)
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