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

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"""Attach a sidecar container that blocks the pod from completing until Airflow pulls result data."""

from __future__ import annotations

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",
                "memory": "10Mi",
            },
        ),
    )





[docs]
def add_xcom_sidecar(
    pod: k8s.V1Pod,
    *,
    sidecar_container_image: str | None = None,
    sidecar_container_resources: k8s.V1ResourceRequirements | dict | None = None,
) -> k8s.V1Pod:
    """Add 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)
    sidecar = copy.deepcopy(PodDefaults.SIDECAR_CONTAINER)
    sidecar.image = sidecar_container_image or PodDefaults.SIDECAR_CONTAINER.image
    if sidecar_container_resources:
        sidecar.resources = sidecar_container_resources
    pod_cp.spec.containers.append(sidecar)

    return pod_cp