Job selection policy

When running a node, you can choose which jobs you want to run by using configuration options, environment variables or flags to specify a job selection policy.

Job selection probes

If you want more control over making the decision to take on jobs, you can use the JobAdmissionControl.ProbeExec and JobAdmissionControl.ProbeHTTP configuration keys.

These are external programs that are passed the following data structure so that they can make a decision about whether to take on a job:

{
  "node_id": "XXX",
  "job_id": "XXX",
  "spec": {
    "engine": "docker",
    "verifier": "ipfs",
    "job_spec_vm": {
      "image": "ubuntu:latest",
      "entrypoint": ["cat", "/file.txt"]
    },
    "inputs": [{
      "engine": "ipfs",
      "cid": "XXX",
      "path": "/file.txt"
    }]
  }
}

The exec probe is a script to run that will be given the job data on stdin, and must exit with status code 0 if the job should be run.

The http probe is a URL to POST the job data to. The job will be rejected if the HTTP request returns a non-positive status code (e.g. >= 400).

If the HTTP response is a JSON blob, it should match the following schema and will be used to respond to the bid directly:

{
  "$schema": "http://json-schema.org/draft-04/schema#",
  "type": "object",
  "properties": {
    "shouldBid": {
      "description": "If the job should be accepted",
      "type": "boolean"
    },
    "shouldWait": {
      "description": "If the node should wait for an async response that will come later. `shouldBid` will be ignored",
      "type": "boolean",
      "default": false,
    },
    "reason": {
      "description": "Human-readable string explaining why the job should be accepted or rejected, or why the wait is required",
      "type": "string"
    }
  },
  "required": [
    "shouldBid",
    "reason"
  ]
}

For example, the following response will reject the job:

{
  "shouldBid": false,
  "reason": "The job did not pass this specific validation: ...",
}

If the HTTP response is not a JSON blob, the content is ignored and any non-error status code will accept the job.