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<@ULVA73B9P> when I try to access labels in base-j...
# ask-marvin
v
@Marvin when I try to access labels in base-job-template like this:
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json
{
  "job_configuration": {
    "apiVersion": "batch/v1",
    "kind": "Job",
    "metadata": {
      "name": "{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}"
    },
    "spec": {
      "template": {
        "metadata": {
          "name": "{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}"
        },
        "spec": {
          "containers": [
            {
              "name": "prefect-job"
            }
          ],
          "restartPolicy": "Never"
        }
      }
    }
  }
}
I get an error:
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File "/usr/local/lib/python3.12/site-packages/prefect_kubernetes/worker.py", line 929, in _create_job
    raise InfrastructureError(
prefect.exceptions.InfrastructureError: Unable to create Kubernetes job: Unprocessable Entity: Job.batch "prefect-flow-run-{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}-svm4f" is invalid: [metadata.generateName: Invalid value: "prefect-flow-run-{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}-": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. '<http://example.com|example.com>', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*'), metadata.name: Invalid value: "prefect-flow-run-{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}-svm4f": a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, '-' or '.', and must start and end with an alphanumeric character (e.g. '<http://example.com|example.com>', regex used for validation is '[a-z0-9]([-a-z0-9]*[a-z0-9])?(\.[a-z0-9]([-a-z0-9]*[a-z0-9])?)*'), spec.template.labels: Invalid value: "prefect-flow-run-{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}-svm4f": a valid label must be an empty string or consist of alphanumeric characters, '-', '_' or '.', and must start and end with an alphanumeric character (e.g. 'MyValue',  or 'my_value',  or '12345', regex used for validation is '(([A-Za-z0-9][-A-Za-z0-9_.]*)?[A-Za-z0-9])?')]
could you help me to integrate flow-run-name from labels and use it as pod name in K8s cluster?
m
✅ thought for 28.9 seconds
Based on the research, I can help you fix the label syntax in your Kubernetes job template. The issue is with how you're trying to access the flow run name. Here's the correct way to do it:
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json
{
  "job_configuration": {
    "apiVersion": "batch/v1",
    "kind": "Job",
    "metadata": {
      "name": "{{ flow_run_name }}"
    },
    "spec": {
      "template": {
        "metadata": {
          "name": "{{ flow_run_name }}"
        },
        "spec": {
          "containers": [
            {
              "name": "prefect-job"
            }
          ],
          "restartPolicy": "Never"
        }
      }
    }
  }
}
Key changes made: 1. Replaced 
labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>']
with 
flow_run_name
2. The 
flow_run_name
is a built-in template variable that Prefect automatically provides Some important notes: 1. The name will automatically be made Kubernetes-compliant (lowercase alphanumeric characters with hyphens) 2. If you need additional labels, you can use the 
labels
template variable which will include all Prefect-specific labels 3. Kubernetes has strict naming requirements (as shown in your error message), but the template system will handle this automatically If you want to include additional labels, you could do:
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json
{
  "job_configuration": {
    "apiVersion": "batch/v1",
    "kind": "Job",
    "metadata": {
      "name": "{{ flow_run_name }}",
      "labels": {{ labels }}
    },
    "spec": {
      "template": {
        "metadata": {
          "name": "{{ flow_run_name }}",
          "labels": {{ labels }}
        },
        "spec": {
          "containers": [
            {
              "name": "prefect-job"
            }
          ],
          "restartPolicy": "Never"
        }
      }
    }
  }
}
This will automatically include all Prefect-specific labels in a Kubernetes-compliant format.
v
@Marvin your suggestion doesn't work:
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Value error, The variables specified in the job configuration template must be present as properties in the variables schema. Your job configuration uses the following undeclared variable(s): flow_run_name.
We need to approach it a little bit differently: we have BaseJobConfiguration in source code. it has labels.
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self.labels = {
            **self._base_flow_run_labels(flow_run),
            **self._base_work_pool_labels(work_pool),
            **self._base_worker_name_label(worker_name),
            **self._base_flow_labels(flow),
            **self._base_deployment_labels(deployment),
            **self.labels,
        }
and
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@staticmethod
    def _base_flow_run_labels(flow_run: "FlowRun") -> dict[str, str]:
        """
        Generate a dictionary of labels for a flow run job.
        """
        return {
            "<http://prefect.io/flow-run-id|prefect.io/flow-run-id>": str(flow_run.id),
            "<http://prefect.io/flow-run-name|prefect.io/flow-run-name>": flow_run.name,
            "<http://prefect.io/version|prefect.io/version>": prefect.__version__,
        }
Now I want to use it and get flow_run.name as pod name
m
✅ thought for 7.8 seconds
Ah, now I understand better! You're working with the internal labels structure of the Kubernetes worker. Let me help you with the correct syntax. For Prefect's Kubernetes worker, to access the flow run name from the labels, you should use:
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json
{
  "job_configuration": {
    "apiVersion": "batch/v1",
    "kind": "Job",
    "metadata": {
      "name": "{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}"
    },
    "spec": {
      "template": {
        "metadata": {
          "name": "{{ labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>'] }}"
        },
        "spec": {
          "containers": [
            {
              "name": "prefect-job"
            }
          ],
          "restartPolicy": "Never"
        }
      }
    }
  }
}
Key changes: 1. Use 
labels['<http://prefect.io/flow-run-name|prefect.io/flow-run-name>']
instead of the full URL format 2. The label key is 
<http://prefect.io/flow-run-name|prefect.io/flow-run-name>
(not the URL-encoded version) This should work because: 1. The 
labels
variable is available in the template context 2. The flow run name is automatically included in these labels by the 
_base_flow_run_labels
method you showed 3. When accessing the labels in the template, we use the simplified form of the label key If you need to access other built-in labels, here are the available keys: - 
<http://prefect.io/flow-run-id|prefect.io/flow-run-id>
- 
<http://prefect.io/flow-run-name|prefect.io/flow-run-name>
- 
<http://prefect.io/version|prefect.io/version>
Let me know if you still encounter any issues with this syntax!
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