I’m trying to filter out the PartitionEOF error log messages that the rdkafka crate produces when you have enable.partition.eof set to true.

We’re using the tracing and tracing-subscriber traits for logging.

The log messages look like this:

{
    "timestamp": ...,
    "level": "ERROR",
    "fields": {
        "message": "librdkafka: Global error: PartitionEOF (Broker: No more messages): Fetch from broker 1 reached end of partition at offset ... (HighwaterMark ...)",
        "log.target": "rdkafka::client",
        ...
    },
    "target": "rdkafka::client",
    "threadId": ...
}

As I understand from the tracing-subscriber documentation, I should be able to do something like this:

    let filter = EnvFilter::from_default_env()
        .add_directive("rdkafka::client[{message="librdkafka: Global error: PartitionEOF.*"}]=off".parse().unwrap());

    tracing_subscriber::fmt()
        .json()
        .with_env_filter(filter)
        .with_thread_ids(true)
        .init();

However, that filter isn’t working. And futhermore, I can’t get any filter to work where I specify the value for a message.

For example, suppose I have the following:

    let filter = EnvFilter::from_default_env()
        .add_directive("[{message="asdf"}]=off".parse().unwrap());

    tracing_subscriber::fmt()
        .json()
        .with_env_filter(filter)
        .with_thread_ids(true)
        .init();

    info!("asdf");

… in that case, the "asdf" message is not filtered out.

Similarly, changing the filter to "[{message=asdf}]=off" does not filter out the "asdf" log message.

However, changing the filter to "[{message}]=off" does filter the message.

What’s going on here? Why is specifying a value not working as per the syntax described in the documentation?

target[span{field=value}]=level