How to get started on Metrics API

[yagnasrinath]

I am having hard time on finding relevant documentation on metrics api. The image on home as well as wiki seems to infer that metrics is not part of GRPC. So, is it a rest api? How can I access metrics of containers from containerd?

[cpuguy83]

@yagnasrinath Metrics are part of the GRPC API of the task service: https://github.com/containerd/containerd/blob/master/api/services/tasks/v1/tasks.proto#L67

containerd also exposes these metrics to the prometheus endpoint (if one is configured) exposed by the containerd daemon.

[kruti11]

@yagnasrinath Were you able to collect metrics of containers from containerd through GRPC in c++ ?

[yagnasrinath]

Unfortunately not. I haven't been able to spend enough time on the effort due to our deadlines.

[kruti11]

oh okay

[szberko]

This is the first time for me to use gRPC. I'm also playing around with the Metrics service, but unfortunately without success. I want to share the command that I think is not far away to send a successful request:

/root/grpcurl -H 'namespace:k8s.io' -rpc-header 'namespace:k8s.io' -reflect-header 'namespace:k8s.io' --plaintext --import-path /root/ --proto tasks.proto -d '{"filters": ["filter1"]}' --unix /run/containerd/containerd.sock containerd.services.tasks.v1.Tasks/Metrics

I'm getting the following error:

ERROR:
  Code: Unknown
  Message: namespace is required: failed precondition

I hope that somebody can answer what I am missing here. I also hope that the command can inspire some of you.

[Sicarius07]

This command gives the metrics of currenty running tasks-
sudo go/bin/grpcurl --plaintext -import-path "/home/ubuntu/containerd/api/services/tasks/v1" --proto /home/ubuntu/containerd/api/services/tasks/v1/tasks.proto -rpc-header 'containerd-namespace: default' --unix /run/containerd/containerd.sock containerd.services.tasks.v1.Tasks/Metrics

but metrics type "io.containerd.cgroups.v2.Metrics" is not recognized/supported.

This is the output of the above command-

  "metrics": [
    {
      "timestamp": "2023-10-10T06:56:38.245697786Z",
      "id": "MA_test_hello2",
      "data": {
        "@error": "io.containerd.cgroups.v2.Metrics is not recognized; see @value for raw binary message data",
        "@type": "io.containerd.cgroups.v2.Metrics",
        "@value": "Cg0IFhD///////////8BEg4I/f7QAhDCsLwCGLrOFCJiCICAxDwQgMC5IxiAgBYg4LRwOIDg4ApAgOABWICgwzxggGBogIDXHXCAwOIFgAH4p1SIAeiMHJABjbICmAHMAdAB2BKAAoCAqmGIAv.........."
      }
    }
  ]
}

Can somebody help me in resolving the same?