CONTAINER_NAME doesn't output the correct "io.kubernetes.container.name" label

[ankitdbst]

With docker, the below daemon.json for journald:

{
    "log-driver": "journald",
    "log-opts": {
      "tag":"{{.ID}}",
      "labels": "io.kubernetes.container.name,io.kubernetes.pod.name"
    }
}

We can filter journalctl logs by IO_KUBERNETES_CONTAINER_NAME=<container-name>. Where container-name is the one defined in the k8s manifest.

      ...
      containers:
      - args:
        ...
        name: kafka

In crio, when logging to journald, the CONTAINER_NAME filter outputs the pod name instead along with some hash:

k8s_kafka_kafka-0_default_4067521d-941e-460a-b8c0-8ec98ecb9dd0_0

Is there a way to configure the fields we send to journald like docker does? So that we can have only kafka returned when doing the filter match?

[haircommander]

Thanks for giving CRI-O a try!

we don't currently support adding a label, so support for that would need to be added.

also, technically, from cri-o's perspective the container name is that whole string. Here's how that string is constructed:

    name := strings.Join([]string{                                                                                                                
        "k8s",                                                                                                                                    
        c.config.Metadata.Name,                                                                                                                   
        c.sboxConfig.Metadata.Name,                                                                                                               
        c.sboxConfig.Metadata.Namespace,                                                                                                          
        c.sboxConfig.Metadata.Uid,                                                                                                                
        fmt.Sprintf("%d", c.config.Metadata.Attempt),                                                                                             
    }, "_")                                                                                                                                       

I don't remember exactly why it's done this way.

What changes would be required to meet your use cases?

[ankitdbst]

Thanks for the reply @haircommander

Yes, if we can provide a way to add the label like docker daemon.json it would be great. Else if we can have another filter IO_KUBERNETES_CONTAINER_NAME with only the container name (c.config.Metadata.Name) then it would help filter logs with it.

Is there a way to plug your filters in before we send out to journald?