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prefect.blocks.kubernetes

KubernetesClusterConfig pydantic-model

Stores configuration for interaction with Kubernetes clusters.

See from_file for creation.

Attributes:

Name Description
config

The entire loaded YAML contents of a kubectl config file

Dict
context_name

The name of the kubectl context to use

str

Examples:

Load a saved Kubernetes cluster config:

from prefect.blocks.kubernetes import KubernetesClusterConfig

cluster_config_block = KubernetesClusterConfig.load("BLOCK_NAME")

Source code in prefect/blocks/kubernetes.py
class KubernetesClusterConfig(Block):
    """
    Stores configuration for interaction with Kubernetes clusters.

    See `from_file` for creation.

    Attributes:
        config: The entire loaded YAML contents of a kubectl config file
        context_name: The name of the kubectl context to use

    Example:
        Load a saved Kubernetes cluster config:
        ```python
        from prefect.blocks.kubernetes import KubernetesClusterConfig

        cluster_config_block = KubernetesClusterConfig.load("BLOCK_NAME")
        ```
    """

    _block_type_name = "Kubernetes Cluster Config"
    _logo_url = "https://images.ctfassets.net/gm98wzqotmnx/1zrSeY8DZ1MJZs2BAyyyGk/20445025358491b8b72600b8f996125b/Kubernetes_logo_without_workmark.svg.png?h=250"

    config: Dict = Field(
        default=..., description="The entire contents of a kubectl config file."
    )
    context_name: str = Field(
        default=..., description="The name of the kubectl context to use."
    )

    @classmethod
    def from_file(cls: Type[Self], path: Path = None, context_name: str = None) -> Self:
        """
        Create a cluster config from the a Kubernetes config file.

        By default, the current context in the default Kubernetes config file will be
        used.

        An alternative file or context may be specified.

        The entire config file will be loaded and stored.
        """
        kube_config = kubernetes.config.kube_config

        path = Path(path or kube_config.KUBE_CONFIG_DEFAULT_LOCATION)
        path = path.expanduser().resolve()

        # Determine the context
        existing_contexts, current_context = kube_config.list_kube_config_contexts(
            config_file=str(path)
        )
        context_names = {ctx["name"] for ctx in existing_contexts}
        if context_name:
            if context_name not in context_names:
                raise ValueError(
                    f"Context {context_name!r} not found. "
                    f"Specify one of: {listrepr(context_names, sep=', ')}."
                )
        else:
            context_name = current_context["name"]

        # Load the entire config file
        config_file_contents = path.read_text()
        config_dict = yaml.safe_load(config_file_contents)

        return cls(config=config_dict, context_name=context_name)

    def get_api_client(self) -> "ApiClient":
        """
        Returns a Kubernetes API client for this cluster config.
        """
        return kubernetes.config.kube_config.new_client_from_config_dict(
            config_dict=self.config, context=self.context_name
        )

    def configure_client(self) -> None:
        """
        Activates this cluster configuration by loading the configuration into the
        Kubernetes Python client. After calling this, Kubernetes API clients can use
        this config's context.
        """
        kubernetes.config.kube_config.load_kube_config_from_dict(
            config_dict=self.config, context=self.context_name
        )

config pydantic-field required

Type: Dict

The entire contents of a kubectl config file.

context_name pydantic-field required

Type: str

The name of the kubectl context to use.

KubernetesClusterConfig.configure_client

Activates this cluster configuration by loading the configuration into the Kubernetes Python client. After calling this, Kubernetes API clients can use this config's context.

Source code in prefect/blocks/kubernetes.py
def configure_client(self) -> None:
    """
    Activates this cluster configuration by loading the configuration into the
    Kubernetes Python client. After calling this, Kubernetes API clients can use
    this config's context.
    """
    kubernetes.config.kube_config.load_kube_config_from_dict(
        config_dict=self.config, context=self.context_name
    )

KubernetesClusterConfig.from_file classmethod

Create a cluster config from the a Kubernetes config file.

By default, the current context in the default Kubernetes config file will be used.

An alternative file or context may be specified.

The entire config file will be loaded and stored.

Source code in prefect/blocks/kubernetes.py
@classmethod
def from_file(cls: Type[Self], path: Path = None, context_name: str = None) -> Self:
    """
    Create a cluster config from the a Kubernetes config file.

    By default, the current context in the default Kubernetes config file will be
    used.

    An alternative file or context may be specified.

    The entire config file will be loaded and stored.
    """
    kube_config = kubernetes.config.kube_config

    path = Path(path or kube_config.KUBE_CONFIG_DEFAULT_LOCATION)
    path = path.expanduser().resolve()

    # Determine the context
    existing_contexts, current_context = kube_config.list_kube_config_contexts(
        config_file=str(path)
    )
    context_names = {ctx["name"] for ctx in existing_contexts}
    if context_name:
        if context_name not in context_names:
            raise ValueError(
                f"Context {context_name!r} not found. "
                f"Specify one of: {listrepr(context_names, sep=', ')}."
            )
    else:
        context_name = current_context["name"]

    # Load the entire config file
    config_file_contents = path.read_text()
    config_dict = yaml.safe_load(config_file_contents)

    return cls(config=config_dict, context_name=context_name)

KubernetesClusterConfig.get_api_client

Returns a Kubernetes API client for this cluster config.

Source code in prefect/blocks/kubernetes.py
def get_api_client(self) -> "ApiClient":
    """
    Returns a Kubernetes API client for this cluster config.
    """
    return kubernetes.config.kube_config.new_client_from_config_dict(
        config_dict=self.config, context=self.context_name
    )