Publishing Headers are unable to store Table with slice values

[jkbmdk]

I'm trying to publish message similar to:

channel.PublishWithContext(
        ctx,
        exchange,
        messageName,
        false,
        false,
        amqp091.Publishing{
            ContentType:  "application/json",
            ContentEncoding: "utf-8",
            Body:  payload,
            Headers: amqp091.Table{"_trace": []string{"a", "b"}},
        }
)

and i receive error
table field "_trace" value []string not supported
I guess problem lies on slice validation https://github.com/streadway/amqp/blob/master/types.go#L232, shouldn't it be done using reflect?
Passing strings vector is not a problem via PHP amqp lib, so it seems to me that this is not the limitation of a rabbitmq.

I'm using

• go version 1.18.1
• amqp091-go v1.5.0

[lukebakken]

Passing strings vector is not a problem via PHP amqp lib

My guess is that the PHP library is able to serialize the data for you. It would be interesting to see what you are doing, so please provide some code I can run to see how this works in PHP.

In your case you should serialize []string{"a", "b"} to a string or binary value, and use that as the value for _trace - https://github.com/rabbitmq/amqp091-go/blob/main/types.go#L210-L230

[jkbmdk]

Sending an unserialized vector is probably build-in rabbit feature. I have not found any serialization in PHP lib and also you are able to publish list using rabbit gui:

and that's the way rabbit displays message with list in header

also comment in https://github.com/streadway/amqp/blob/master/types.go#L213 suggests that you should be able to pass e.g. []string to header value. Today I'll try to create pull request with a fix proposal

[Zerpet]

I'm not sure we claim to have support for []string values, based on https://pkg.go.dev/github.com/rabbitmq/amqp091-go#Table

I'm happy to review a PR to add support for lists of supported AMQP types.

[jkbmdk]

That was my fault, I've misunderstood some concepts and I'm able to pass _trace like this

channel.PublishWithContext(
        ctx,
        exchange,
        messageName,
        false,
        false,
        amqp091.Publishing{
            ContentType:  "application/json",
            ContentEncoding: "utf-8",
            Body:  payload,
            Headers: amqp091.Table{"_trace": []interface{}{"a", "b"}},
        }
)