Source code for airflow.providers.cncf.kubernetes.utils.xcom_sidecar

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"""
This module handles all xcom functionality for the KubernetesPodOperator
by attaching a sidecar container that blocks the pod from completing until
Airflow has pulled result data into the worker for xcom serialization.
"""
import copy

from kubernetes.client import models as k8s


[docs]class PodDefaults: """Static defaults for Pods"""
[docs] XCOM_MOUNT_PATH = '/airflow/xcom'
[docs] SIDECAR_CONTAINER_NAME = 'airflow-xcom-sidecar'
[docs] XCOM_CMD = 'trap "exit 0" INT; while true; do sleep 1; done;'
[docs] VOLUME_MOUNT = k8s.V1VolumeMount(name='xcom', mount_path=XCOM_MOUNT_PATH)
[docs] VOLUME = k8s.V1Volume(name='xcom', empty_dir=k8s.V1EmptyDirVolumeSource())
[docs] SIDECAR_CONTAINER = k8s.V1Container( name=SIDECAR_CONTAINER_NAME, command=['sh', '-c', XCOM_CMD], image='alpine', volume_mounts=[VOLUME_MOUNT], resources=k8s.V1ResourceRequirements( requests={ "cpu": "1m",
} ), )
[docs]def add_xcom_sidecar(pod: k8s.V1Pod) -> k8s.V1Pod: """Adds sidecar""" pod_cp = copy.deepcopy(pod) pod_cp.spec.volumes = pod.spec.volumes or [] pod_cp.spec.volumes.insert(0, PodDefaults.VOLUME) pod_cp.spec.containers[0].volume_mounts = pod_cp.spec.containers[0].volume_mounts or [] pod_cp.spec.containers[0].volume_mounts.insert(0, PodDefaults.VOLUME_MOUNT) pod_cp.spec.containers.append(PodDefaults.SIDECAR_CONTAINER) return pod_cp

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