在发送 grpc 请求时 header 无法支持数组

[binwan-dev]

下午好，我在调试微服务发送一个grpc请求时，由于我们需要在 header 中传递数组，此时我看到源码中在组装header头时使用了 header.get方法，该方法只取第一个值，导致数组无法传递给后者微服务。

代码链接

Environment:

• kratos version v2.9.2
• go version：1.24.0
• macos 26

[dosubot]

Hi @binwan-dev! I'm Dosu and I'm helping the Kratos team.

You're right — this is a bug. In unaryClientInterceptor, the header propagation loop uses header.Get(k) which only returns the first value [1]. However, the Header interface already defines a Values(key string) []string method that returns all values for a given key [2].

The fix would be to replace:

for _, k := range keys {
    keyvals = append(keyvals, k, header.Get(k))
}

with:

for _, k := range keys {
    for _, v := range header.Values(k) {
        keyvals = append(keyvals, k, v)
    }
}

This way grpcmd.AppendToOutgoingContext() will receive all header values and properly propagate them to downstream services. Would you be interested in submitting a PR for this?

To reply, just mention @dosu.

---

Docs are dead. Just use Dosu.

[binwan-dev]

@dosu 我已经提交了PR，#3858

[dosubot]

感谢你这么快就提交了 PR #3858！修改方向看起来是正确的，希望能尽快被合并 🎉

To reply, just mention @dosu.

---

Docs are dead. Just use Dosu.

[waterWang]

Thanks for the report! I've submitted PR #3865 which fixes this by using header.Values(k) instead of header.Get(k) to forward all values for array headers, not just the first one.

[binwan-dev]

Thanks for the report! I've submitted PR #3865 which fixes this by using header.Values(k) instead of header.Get(k) to forward all values for array headers, not just the first one.

额，我不是已经提过pr了吗？我看到你重新提了个pr，好吧，不过问题解决了就行了