# Copyright 2019 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import inspect
import re
import warnings
from typing import Any, Dict, List, TypeVar, Union, Callable, Optional, Sequence

from kubernetes.client import V1Toleration, V1Affinity
from kubernetes.client.models import (V1Container, V1EnvVar, V1EnvFromSource,
                                      V1SecurityContext, V1Probe,
                                      V1ResourceRequirements, V1VolumeDevice,
                                      V1VolumeMount, V1ContainerPort,
                                      V1Lifecycle, V1Volume)

from kfp.components import _structures
from kfp.dsl import _pipeline_param
from kfp.pipeline_spec import pipeline_spec_pb2

# generics
T = TypeVar('T')
# type alias: either a string or a list of string
StringOrStringList = Union[str, List[str]]

ALLOWED_RETRY_POLICIES = (
    'Always',
    'OnError',
    'OnFailure',
)

# Shorthand for PipelineContainerSpec
_PipelineContainerSpec = pipeline_spec_pb2.PipelineDeploymentConfig.PipelineContainerSpec

# Unit constants for k8s size string.
_E = 10**18  # Exa
_EI = 1 << 60  # Exa: power-of-two approximate
_P = 10**15  # Peta
_PI = 1 << 50  # Peta: power-of-two approximate
# noinspection PyShadowingBuiltins
_T = 10**12  # Tera
_TI = 1 << 40  # Tera: power-of-two approximate
_G = 10**9  # Giga
_GI = 1 << 30  # Giga: power-of-two approximate
_M = 10**6  # Mega
_MI = 1 << 20  # Mega: power-of-two approximate
_K = 10**3  # Kilo
_KI = 1 << 10  # Kilo: power-of-two approximate

_GKE_ACCELERATOR_LABEL = 'cloud.google.com/gke-accelerator'


# util functions
def deprecation_warning(func: Callable, op_name: str,
                        container_name: str) -> Callable:
  """Decorator function to give a pending deprecation warning."""

  def _wrapped(*args, **kwargs):
    warnings.warn(
        '`dsl.ContainerOp.%s` will be removed in future releases. '
        'Use `dsl.ContainerOp.container.%s` instead.' %
        (op_name, container_name), PendingDeprecationWarning)
    return func(*args, **kwargs)

  return _wrapped


def _create_getter_setter(prop):
  """Create a tuple of getter and setter methods for a property in `Container`."""

  def _getter(self):
    return getattr(self._container, prop)

  def _setter(self, value):
    return setattr(self._container, prop, value)

  return _getter, _setter


def _proxy_container_op_props(cls: 'ContainerOp'):
  """Takes the `ContainerOp` class and proxy the PendingDeprecation properties in `ContainerOp` to the `Container` instance. """
  # properties mapping to proxy: ContainerOps.<prop> => Container.<prop>
  prop_map = dict(image='image', env_variables='env')
  # itera and create class props
  for op_prop, container_prop in prop_map.items():
    # create getter and setter
    _getter, _setter = _create_getter_setter(container_prop)
    # decorate with deprecation warning
    getter = deprecation_warning(_getter, op_prop, container_prop)
    setter = deprecation_warning(_setter, op_prop, container_prop)
    # update attribites with properties
    setattr(cls, op_prop, property(getter, setter))
  return cls


def as_string_list(
    list_or_str: Optional[Union[Any, Sequence[Any]]]) -> List[str]:
  """Convert any value except None to a list if not already a list."""
  if list_or_str is None:
    return None
  if isinstance(list_or_str, Sequence) and not isinstance(list_or_str, str):
    list_value = list_or_str
  else:
    list_value = [list_or_str]
  return [str(item) for item in list_value]


def create_and_append(current_list: Union[List[T], None], item: T) -> List[T]:
  """Create a list (if needed) and appends an item to it."""
  current_list = current_list or []
  current_list.append(item)
  return current_list


class Container(V1Container):
  """
  A wrapper over k8s container definition object
  (io.k8s.api.core.v1.Container),
  which is used to represent the `container` property in argo's workflow
  template (io.argoproj.workflow.v1alpha1.Template).

  `Container` class also comes with utility functions to set and update the
  the various properties for a k8s container definition.

  NOTE: A notable difference is that `name` is not required and will not be
  processed for `Container` (in contrast to `V1Container` where `name` is a
  required property).

  See:
  *
  https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_container.py
  * https://github.com/argoproj/argo/blob/master/api/openapi-spec/swagger.json

  Example::

    from kfp.dsl import ContainerOp
    from kubernetes.client.models import V1EnvVar


    # creates a operation
    op = ContainerOp(name='bash-ops',
                    image='busybox:latest',
                    command=['echo'],
                    arguments=['$MSG'])

    # returns a `Container` object from `ContainerOp`
    # and add an environment variable to `Container`
    op.container.add_env_variable(V1EnvVar(name='MSG', value='hello world'))

  Attributes:
    attribute_map (dict): The key is attribute name and the value is json key
      in definition.
  """
  # remove `name` from attribute_map, swagger_types and openapi_types so `name` is not generated in the JSON

  if hasattr(V1Container, 'swagger_types'):
    swagger_types = {
        key: value
        for key, value in V1Container.swagger_types.items()
        if key != 'name'
    }
  if hasattr(V1Container, 'openapi_types'):
    openapi_types = {
        key: value
        for key, value in V1Container.openapi_types.items()
        if key != 'name'
    }
  attribute_map = {
      key: value
      for key, value in V1Container.attribute_map.items()
      if key != 'name'
  }

  def __init__(self, image: str, command: List[str], args: List[str], **kwargs):
    """Creates a new instance of `Container`.

    Args:
      image {str}: image to use, e.g. busybox:latest
      command {List[str]}: entrypoint array.  Not executed within a shell.
      args {List[str]}: arguments to entrypoint.
      **kwargs: keyword arguments for `V1Container`
    """
    # set name to '' if name is not provided
    # k8s container MUST have a name
    # argo workflow template does not need a name for container def
    if not kwargs.get('name'):
      kwargs['name'] = ''

    # v2 container_spec
    self._container_spec = None

    super(Container, self).__init__(image=image,
                                    command=command,
                                    args=args,
                                    **kwargs)

  def _validate_size_string(self, size_string):
    """Validate a given string is valid for memory/ephemeral-storage request or limit."""

    if isinstance(size_string, _pipeline_param.PipelineParam):
      if size_string.value:
        size_string = size_string.value
      else:
        return

    if re.match(r'^[0-9]+(E|Ei|P|Pi|T|Ti|G|Gi|M|Mi|K|Ki){0,1}$',
                size_string) is None:
      raise ValueError(
          'Invalid memory string. Should be an integer, or integer followed '
          'by one of "E|Ei|P|Pi|T|Ti|G|Gi|M|Mi|K|Ki"')

  def _validate_cpu_string(self, cpu_string):
    'Validate a given string is valid for cpu request or limit.'

    if isinstance(cpu_string, _pipeline_param.PipelineParam):
      if cpu_string.value:
        cpu_string = cpu_string.value
      else:
        return

    if re.match(r'^[0-9]+m$', cpu_string) is not None:
      return

    try:
      float(cpu_string)
    except ValueError:
      raise ValueError(
          'Invalid cpu string. Should be float or integer, or integer followed '
          'by "m".')

  def _validate_positive_number(self, str_value, param_name):
    'Validate a given string is in positive integer format.'

    if isinstance(str_value, _pipeline_param.PipelineParam):
      if str_value.value:
        str_value = str_value.value
      else:
        return

    try:
      int_value = int(str_value)
    except ValueError:
      raise ValueError('Invalid {}. Should be integer.'.format(param_name))

    if int_value <= 0:
      raise ValueError('{} must be positive integer.'.format(param_name))

  def add_resource_limit(self, resource_name, value) -> 'Container':
    """Add the resource limit of the container.

    Args:
      resource_name: The name of the resource. It can be cpu, memory, etc.
      value: The string value of the limit.
    """

    self.resources = self.resources or V1ResourceRequirements()
    self.resources.limits = self.resources.limits or {}
    self.resources.limits.update({resource_name: value})
    return self

  def add_resource_request(self, resource_name, value) -> 'Container':
    """Add the resource request of the container.

    Args:
      resource_name: The name of the resource. It can be cpu, memory, etc.
      value: The string value of the request.
    """

    self.resources = self.resources or V1ResourceRequirements()
    self.resources.requests = self.resources.requests or {}
    self.resources.requests.update({resource_name: value})
    return self

  def set_memory_request(self, memory) -> 'Container':
    """Set memory request (minimum) for this operator.

    Args:
      memory: a string which can be a number or a number followed by one of
        "E", "P", "T", "G", "M", "K".
    """

    self._validate_size_string(memory)
    return self.add_resource_request('memory', memory)

  def set_memory_limit(self, memory) -> 'Container':
    """Set memory limit (maximum) for this operator.

    Args:
      memory: a string which can be a number or a number followed by one of
        "E", "P", "T", "G", "M", "K".
    """
    self._validate_size_string(memory)
    if self._container_spec:
      self._container_spec.resources.memory_limit = _get_resource_number(memory)
    return self.add_resource_limit('memory', memory)

  def set_ephemeral_storage_request(self, size) -> 'Container':
    """Set ephemeral-storage request (minimum) for this operator.

    Args:
      size: a string which can be a number or a number followed by one of
        "E", "P", "T", "G", "M", "K".
    """
    self._validate_size_string(size)
    return self.add_resource_request('ephemeral-storage', size)

  def set_ephemeral_storage_limit(self, size) -> 'Container':
    """Set ephemeral-storage request (maximum) for this operator.

    Args:
      size: a string which can be a number or a number followed by one of
        "E", "P", "T", "G", "M", "K".
    """
    self._validate_size_string(size)
    return self.add_resource_limit('ephemeral-storage', size)

  def set_cpu_request(self, cpu) -> 'Container':
    """Set cpu request (minimum) for this operator.

    Args:
      cpu: A string which can be a number or a number followed by "m", which
        means 1/1000.
    """

    self._validate_cpu_string(cpu)
    return self.add_resource_request('cpu', cpu)

  def set_cpu_limit(self, cpu) -> 'Container':
    """Set cpu limit (maximum) for this operator.

    Args:
      cpu: A string which can be a number or a number followed by "m", which
        means 1/1000.
    """
    self._validate_cpu_string(cpu)
    if self._container_spec:
      self._container_spec.resources.cpu_limit = _get_cpu_number(cpu)
    return self.add_resource_limit('cpu', cpu)

  def set_gpu_limit(self, gpu, vendor='nvidia') -> 'Container':
    """Set gpu limit for the operator.

    This function add '<vendor>.com/gpu' into resource limit.
    Note that there is no need to add GPU request. GPUs are only supposed to
    be specified in the limits section. See
    https://kubernetes.io/docs/tasks/manage-gpus/scheduling-gpus/.

    Args:
      gpu: A string which must be a positive number.
      vendor: Optional. A string which is the vendor of the requested gpu.
        The supported values are: 'nvidia' (default), and 'amd'. The value is
        ignored in v2.
    """
    self._validate_positive_number(gpu, 'gpu')

    if self._container_spec:
      # For backforward compatibiliy, allow `gpu` to be a string.
      self._container_spec.resources.accelerator.count = int(gpu)

    if vendor != 'nvidia' and vendor != 'amd':
      raise ValueError('vendor can only be nvidia or amd.')

    return self.add_resource_limit('%s.com/gpu' % vendor, gpu)

  def add_volume_mount(self, volume_mount) -> 'Container':
    """Add volume to the container

    Args:
      volume_mount: Kubernetes volume mount For detailed spec, check volume
        mount definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_volume_mount.py
    """

    if not isinstance(volume_mount, V1VolumeMount):
      raise ValueError('invalid argument. Must be of instance `V1VolumeMount`.')

    self.volume_mounts = create_and_append(self.volume_mounts, volume_mount)
    return self

  def add_volume_devices(self, volume_device) -> 'Container':
    """Add a block device to be used by the container.

    Args:
      volume_device: Kubernetes volume device For detailed spec, volume
        device definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_volume_device.py
    """

    if not isinstance(volume_device, V1VolumeDevice):
      raise ValueError(
          'invalid argument. Must be of instance `V1VolumeDevice`.')

    self.volume_devices = create_and_append(self.volume_devices, volume_device)
    return self

  def add_env_variable(self, env_variable) -> 'Container':
    """Add environment variable to the container.

    Args:
      env_variable: Kubernetes environment variable For detailed spec, check
        environment variable definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_env_var.py
    """

    if not isinstance(env_variable, V1EnvVar):
      raise ValueError('invalid argument. Must be of instance `V1EnvVar`.')

    self.env = create_and_append(self.env, env_variable)
    return self

  def add_env_from(self, env_from) -> 'Container':
    """Add a source to populate environment variables int the container.

    Args:
      env_from: Kubernetes environment from source For detailed spec, check
        environment from source definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_env_var_source.py
    """

    if not isinstance(env_from, V1EnvFromSource):
      raise ValueError(
          'invalid argument. Must be of instance `V1EnvFromSource`.')

    self.env_from = create_and_append(self.env_from, env_from)
    return self

  def set_image_pull_policy(self, image_pull_policy) -> 'Container':
    """Set image pull policy for the container.

    Args:
      image_pull_policy: One of `Always`, `Never`, `IfNotPresent`.
    """
    if image_pull_policy not in ['Always', 'Never', 'IfNotPresent']:
      raise ValueError(
          'Invalid imagePullPolicy. Must be one of `Always`, `Never`, `IfNotPresent`.'
      )

    self.image_pull_policy = image_pull_policy
    return self

  def add_port(self, container_port) -> 'Container':
    """Add a container port to the container.

    Args:
      container_port: Kubernetes container port For detailed spec, check
        container port definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_container_port.py
    """

    if not isinstance(container_port, V1ContainerPort):
      raise ValueError(
          'invalid argument. Must be of instance `V1ContainerPort`.')

    self.ports = create_and_append(self.ports, container_port)
    return self

  def set_security_context(self, security_context) -> 'Container':
    """Set security configuration to be applied on the container.

    Args:
      security_context: Kubernetes security context For detailed spec, check
        security context definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_security_context.py
    """

    if not isinstance(security_context, V1SecurityContext):
      raise ValueError(
          'invalid argument. Must be of instance `V1SecurityContext`.')

    self.security_context = security_context
    return self

  def set_stdin(self, stdin=True) -> 'Container':
    """
    Whether this container should allocate a buffer for stdin in the container
    runtime. If this is not set, reads from stdin in the container will always
    result in EOF.

    Args:
      stdin: boolean flag
    """

    self.stdin = stdin
    return self

  def set_stdin_once(self, stdin_once=True) -> 'Container':
    """
    Whether the container runtime should close the stdin channel after it has
    been opened by a single attach. When stdin is true the stdin stream will
    remain open across multiple attach sessions. If stdinOnce is set to true,
    stdin is opened on container start, is empty until the first client attaches
    to stdin, and then remains open and accepts data until the client
    disconnects, at which time stdin is closed and remains closed until the
    container is restarted. If this flag is false, a container processes that
    reads from stdin will never receive an EOF.

    Args:
      stdin_once: boolean flag
    """

    self.stdin_once = stdin_once
    return self

  def set_termination_message_path(self,
                                   termination_message_path) -> 'Container':
    """
    Path at which the file to which the container's termination message will
    be written is mounted into the container's filesystem. Message written is
    intended to be brief final status, such as an assertion failure message.
    Will be truncated by the node if greater than 4096 bytes. The total message
    length across all containers will be limited to 12kb.

    Args:
      termination_message_path: path for the termination message
    """
    self.termination_message_path = termination_message_path
    return self

  def set_termination_message_policy(self,
                                     termination_message_policy) -> 'Container':
    """
    Indicate how the termination message should be populated. File will use the
    contents of terminationMessagePath to populate the container status message
    on both success and failure. FallbackToLogsOnError will use the last chunk
    of container log output if the termination message file is empty and the
    container exited with an error. The log output is limited to 2048 bytes or
    80 lines, whichever is smaller.

    Args:
      termination_message_policy: `File` or `FallbackToLogsOnError`
    """
    if termination_message_policy not in ['File', 'FallbackToLogsOnError']:
      raise ValueError(
          'terminationMessagePolicy must be `File` or `FallbackToLogsOnError`')
    self.termination_message_policy = termination_message_policy
    return self

  def set_tty(self, tty: bool = True) -> 'Container':
    """
    Whether this container should allocate a TTY for itself, also requires
    'stdin' to be true.

    Args:
      tty: boolean flag
    """

    self.tty = tty
    return self

  def set_readiness_probe(self, readiness_probe) -> 'Container':
    """Set a readiness probe for the container.

    Args:
      readiness_probe: Kubernetes readiness probe For detailed spec, check
        probe definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_probe.py
    """

    if not isinstance(readiness_probe, V1Probe):
      raise ValueError('invalid argument. Must be of instance `V1Probe`.')

    self.readiness_probe = readiness_probe
    return self

  def set_liveness_probe(self, liveness_probe) -> 'Container':
    """Set a liveness probe for the container.

    Args:
      liveness_probe: Kubernetes liveness probe For detailed spec, check
        probe definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_probe.py
    """

    if not isinstance(liveness_probe, V1Probe):
      raise ValueError('invalid argument. Must be of instance `V1Probe`.')

    self.liveness_probe = liveness_probe
    return self

  def set_lifecycle(self, lifecycle) -> 'Container':
    """Setup a lifecycle config for the container.

    Args:
      lifecycle: Kubernetes lifecycle For detailed spec, lifecycle
        definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_lifecycle.py
    """

    if not isinstance(lifecycle, V1Lifecycle):
      raise ValueError('invalid argument. Must be of instance `V1Lifecycle`.')

    self.lifecycle = lifecycle
    return self


class UserContainer(Container):
  """
  Represents an argo workflow UserContainer
  (io.argoproj.workflow.v1alpha1.UserContainer)
  to be used in `UserContainer` property in argo's workflow template
  (io.argoproj.workflow.v1alpha1.Template).

  `UserContainer` inherits from `Container` class with an addition of
  `mirror_volume_mounts`
  attribute (`mirrorVolumeMounts` property).

  See
  https://github.com/argoproj/argo/blob/master/api/openapi-spec/swagger.json

  Args:
    name: unique name for the user container
    image: image to use for the user container, e.g. redis:alpine
    command: entrypoint array.  Not executed within a shell.
    args: arguments to the entrypoint.
    mirror_volume_mounts: MirrorVolumeMounts will mount the same volumes
      specified in the main container to the container (including
      artifacts), at the same mountPaths. This enables dind daemon to
      partially see the same filesystem as the main container in order to
      use features such as docker volume binding
    **kwargs: keyword arguments available for `Container`

  Attributes:
    swagger_types (dict): The key is attribute name and the value is attribute
      type.

  Example ::

    from kfp.dsl import ContainerOp, UserContainer
    # creates a `ContainerOp` and adds a redis init container
    op = (ContainerOp(name='foo-op', image='busybox:latest')
       .add_initContainer(UserContainer(name='redis', image='redis:alpine')))
  """
  # adds `mirror_volume_mounts` to `UserContainer` swagger definition
  # NOTE inherits definition from `V1Container` rather than `Container`
  #      because `Container` has no `name` property.
  if hasattr(V1Container, 'swagger_types'):
    swagger_types = dict(**V1Container.swagger_types,
                         mirror_volume_mounts='bool')
  if hasattr(V1Container, 'openapi_types'):
    openapi_types = dict(**V1Container.openapi_types,
                         mirror_volume_mounts='bool')
  attribute_map = dict(**V1Container.attribute_map,
                       mirror_volume_mounts='mirrorVolumeMounts')

  def __init__(self,
               name: str,
               image: str,
               command: StringOrStringList = None,
               args: StringOrStringList = None,
               mirror_volume_mounts: bool = None,
               **kwargs):
    super().__init__(name=name,
                     image=image,
                     command=as_string_list(command),
                     args=as_string_list(args),
                     **kwargs)

    self.mirror_volume_mounts = mirror_volume_mounts

  def set_mirror_volume_mounts(self, mirror_volume_mounts=True):
    """
    Setting mirrorVolumeMounts to true will mount the same volumes specified
    in the main container to the container (including artifacts), at the same
    mountPaths. This enables dind daemon to partially see the same filesystem
    as the main container in order to use features such as docker volume
    binding.

    Args:
        mirror_volume_mounts: boolean flag
    """

    self.mirror_volume_mounts = mirror_volume_mounts
    return self

  @property
  def inputs(self):
    """A list of PipelineParam found in the UserContainer object."""
    return _pipeline_param.extract_pipelineparams_from_any(self)


class Sidecar(UserContainer):
  """Creates a new instance of `Sidecar`.

  Args:
    name: unique name for the sidecar container
    image: image to use for the sidecar container, e.g. redis:alpine
    command: entrypoint array.  Not executed within a shell.
    args: arguments to the entrypoint.
    mirror_volume_mounts: MirrorVolumeMounts will mount the same volumes
      specified in the main container to the sidecar (including artifacts),
      at the same mountPaths. This enables dind daemon to partially see the
      same filesystem as the main container in order to use features such as
      docker volume binding
    **kwargs: keyword arguments available for `Container`
  """

  def __init__(self,
               name: str,
               image: str,
               command: StringOrStringList = None,
               args: StringOrStringList = None,
               mirror_volume_mounts: bool = None,
               **kwargs):
    super().__init__(name=name,
                     image=image,
                     command=command,
                     args=args,
                     mirror_volume_mounts=mirror_volume_mounts,
                     **kwargs)


def _make_hash_based_id_for_op(op):
  # Generating a unique ID for Op. For class instances, the hash is the object's memory address which is unique.
  return op.human_name + ' ' + hex(2**63 + hash(op))[2:]


# Pointer to a function that generates a unique ID for the Op instance (Possibly by registering the Op instance in some system).
_register_op_handler = _make_hash_based_id_for_op


class BaseOp(object):
  """Base operator

  Args:
    name: the name of the op. It does not have to be unique within a
      pipeline because the pipeline will generates a unique new name in case
      of conflicts.
    init_containers: the list of `UserContainer` objects describing the
      InitContainer to deploy before the `main` container.
    sidecars: the list of `Sidecar` objects describing the sidecar
      containers to deploy together with the `main` container.
    is_exit_handler: Deprecated.
  """

  # list of attributes that might have pipeline params - used to generate
  # the input parameters during compilation.
  # Excludes `file_outputs` and `outputs` as they are handled separately
  # in the compilation process to generate the DAGs and task io parameters.
  attrs_with_pipelineparams = [
      'node_selector', 'volumes', 'pod_annotations', 'pod_labels',
      'num_retries', 'init_containers', 'sidecars', 'tolerations'
  ]

  def __init__(self,
               name: str,
               init_containers: List[UserContainer] = None,
               sidecars: List[Sidecar] = None,
               is_exit_handler: bool = False):

    if is_exit_handler:
      warnings.warn('is_exit_handler=True is no longer needed.',
                    DeprecationWarning)

    self.is_exit_handler = is_exit_handler

    # human_name must exist to construct operator's name
    self.human_name = name
    self.display_name = None  #TODO Set display_name to human_name
    # ID of the current Op. Ideally, it should be generated by the compiler that sees the bigger context.
    # However, the ID is used in the task output references (PipelineParams) which can be serialized to strings.
    # Because of this we must obtain a unique ID right now.
    self.name = _register_op_handler(self)

    # TODO: proper k8s definitions so that `convert_k8s_obj_to_json` can be used?
    # `io.argoproj.workflow.v1alpha1.Template` properties
    self.node_selector = {}
    self.volumes = []
    self.tolerations = []
    self.affinity = {}
    self.pod_annotations = {}
    self.pod_labels = {}

    # Retry strategy
    self.num_retries = 0
    self.retry_policy = None
    self.backoff_factor = None
    self.backoff_duration = None
    self.backoff_max_duration = None

    self.timeout = 0
    self.init_containers = init_containers or []
    self.sidecars = sidecars or []

    # used to mark this op with loop arguments
    self.loop_args = None

    # attributes specific to `BaseOp`
    self._inputs = []
    self.dependent_names = []

  @property
  def inputs(self):
    """List of PipelineParams that will be converted into input parameters
    (io.argoproj.workflow.v1alpha1.Inputs) for the argo workflow.
    """
    # Iterate through and extract all the `PipelineParam` in Op when
    # called the 1st time (because there are in-place updates to `PipelineParam`
    # during compilation - remove in-place updates for easier debugging?)
    if not self._inputs:
      self._inputs = []
      # TODO replace with proper k8s obj?
      for key in self.attrs_with_pipelineparams:
        self._inputs += _pipeline_param.extract_pipelineparams_from_any(
            getattr(self, key))
      # keep only unique
      self._inputs = list(set(self._inputs))
    return self._inputs

  @inputs.setter
  def inputs(self, value):
    # to support in-place updates
    self._inputs = value

  def apply(self, mod_func):
    """Applies a modifier function to self.

    The function should return the passed object.
    This is needed to chain "extention methods" to this class.

    Example::

      from kfp.gcp import use_gcp_secret
      task = (
          train_op(...)
              .set_memory_request('1G')
              .apply(use_gcp_secret('user-gcp-sa'))
              .set_memory_limit('2G')
      )
  """
    return mod_func(self) or self

  def after(self, *ops):
    """Specify explicit dependency on other ops."""
    for op in ops:
      self.dependent_names.append(op.name)
    return self

  def add_volume(self, volume):
    """Add K8s volume to the container

    Args:
      volume: Kubernetes volumes For detailed spec, check volume definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_volume.py
    """
    self.volumes.append(volume)
    return self

  def add_toleration(self, tolerations: V1Toleration):
    """Add K8s tolerations

    Args:
      tolerations: Kubernetes toleration For detailed spec, check toleration
        definition
        https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_toleration.py
    """
    self.tolerations.append(tolerations)
    return self

  def add_affinity(self, affinity: V1Affinity):
    """Add K8s Affinity

    Args:
      affinity: Kubernetes affinity For detailed spec, check affinity
        definition
      https://github.com/kubernetes-client/python/blob/master/kubernetes/client/models/v1_affinity.py

    Example::

      V1Affinity(
          node_affinity=V1NodeAffinity(
              required_during_scheduling_ignored_during_execution=V1NodeSelector(
                  node_selector_terms=[V1NodeSelectorTerm(
                      match_expressions=[V1NodeSelectorRequirement(
                          key='beta.kubernetes.io/instance-type',
                          operator='In',
                          values=['p2.xlarge'])])])))
    """
    self.affinity = affinity
    return self

  def add_node_selector_constraint(self, label_name, value):
    """Add a constraint for nodeSelector.

    Each constraint is a key-value pair label.
    For the container to be eligible to run on a node, the node must have each
    of the constraints appeared as labels.

    Args:
      label_name: The name of the constraint label.
      value: The value of the constraint label.
    """

    self.node_selector[label_name] = value
    return self

  def add_pod_annotation(self, name: str, value: str):
    """Adds a pod's metadata annotation.

    Args:
      name: The name of the annotation.
      value: The value of the annotation.
    """

    self.pod_annotations[name] = value
    return self

  def add_pod_label(self, name: str, value: str):
    """Adds a pod's metadata label.

    Args:
      name: The name of the label.
      value: The value of the label.
    """

    self.pod_labels[name] = value
    return self

  def set_retry(self,
                num_retries: int,
                policy: Optional[str] = None,
                backoff_duration: Optional[str] = None,
                backoff_factor: Optional[float] = None,
                backoff_max_duration: Optional[str] = None):
    """Sets the number of times the task is retried until it's declared failed.

    Args:
      num_retries: Number of times to retry on failures.
      policy: Retry policy name.
      backoff_duration: The time interval between retries. Defaults to an
        immediate retry. In case you specify a simple number, the unit
        defaults to seconds. You can also specify a different unit, for
        instance, 2m (2 minutes), 1h (1 hour).
      backoff_factor: The exponential backoff factor applied to
        backoff_duration. For example, if backoff_duration="60"
        (60 seconds) and backoff_factor=2, the first retry will happen
        after 60 seconds, then after 120, 240, and so on.
      backoff_max_duration: The maximum interval that can be reached with
        the backoff strategy.
    """
    if policy is not None and policy not in ALLOWED_RETRY_POLICIES:
      raise ValueError('policy must be one of: %r' % (ALLOWED_RETRY_POLICIES,))

    self.num_retries = num_retries
    self.retry_policy = policy
    self.backoff_factor = backoff_factor
    self.backoff_duration = backoff_duration
    self.backoff_max_duration = backoff_max_duration
    return self

  def set_timeout(self, seconds: int):
    """Sets the timeout for the task in seconds.

    Args:
      seconds: Number of seconds.
    """

    self.timeout = seconds
    return self

  def add_init_container(self, init_container: UserContainer):
    """Add a init container to the Op.

    Args:
      init_container: UserContainer object.
    """

    self.init_containers.append(init_container)
    return self

  def add_sidecar(self, sidecar: Sidecar):
    """Add a sidecar to the Op.

    Args:
      sidecar: SideCar object.
    """

    self.sidecars.append(sidecar)
    return self

  def set_display_name(self, name: str):
    self.display_name = name
    return self

  def __repr__(self):
    return str({self.__class__.__name__: self.__dict__})


from ._pipeline_volume import PipelineVolume  # The import is here to prevent circular reference problems.


class InputArgumentPath:

  def __init__(self, argument, input=None, path=None):
    self.argument = argument
    self.input = input
    self.path = path


class ContainerOp(BaseOp):
  """Represents an op implemented by a container image.

   Args:
     name: the name of the op. It does not have to be unique within a
       pipeline because the pipeline will generates a unique new name in case
       of conflicts.
     image: the container image name, such as 'python:3.5-jessie'
     command: the command to run in the container. If None, uses default CMD
       in defined in container.
     arguments: the arguments of the command. The command can include "%s"
       and supply a PipelineParam as the string replacement. For example,
       ('echo %s' % input_param). At container run time the argument will be
       'echo param_value'.
     init_containers: the list of `UserContainer` objects describing the
       InitContainer to deploy before the `main` container.
     sidecars: the list of `Sidecar` objects describing the sidecar
       containers to deploy together with the `main` container.
     container_kwargs: the dict of additional keyword arguments to pass to
       the op's `Container` definition.
     artifact_argument_paths: Optional. Maps input artifact arguments (values
       or references) to the local file paths where they'll be placed. At
       pipeline run time, the value of the artifact argument is saved to a
       local file with specified path. This parameter is only needed when the
       input file paths are hard-coded in the program. Otherwise it's better
       to pass input artifact placement paths by including artifact arguments
       in the command-line using the InputArgumentPath class instances.
     file_outputs: Maps output names to container local output file paths.
       The system will take the data from those files and will make it
       available for passing to downstream tasks. For each output in the
       file_outputs map there will be a corresponding output reference
       available in the task.outputs dictionary. These output references can
       be passed to the other tasks as arguments. The following output names
       are handled specially by the frontend and
           backend: "mlpipeline-ui-metadata" and "mlpipeline-metrics".
     output_artifact_paths: Deprecated. Maps output artifact labels to local
       artifact file paths. Deprecated: Use file_outputs instead. It now
         supports big data outputs.
     is_exit_handler: Deprecated. This is no longer needed.
     pvolumes: Dictionary for the user to match a path on the op's fs with a
       V1Volume or it inherited type.
         E.g {"/my/path": vol, "/mnt": other_op.pvolumes["/output"]}.

   Example::

     from kfp import dsl
     from kubernetes.client.models import V1EnvVar, V1SecretKeySelector
     @dsl.pipeline(
         name='foo',
         description='hello world')
     def foo_pipeline(tag: str, pull_image_policy: str):
       # any attributes can be parameterized (both serialized string or actual PipelineParam)
       op = dsl.ContainerOp(name='foo',
                           image='busybox:%s' % tag,
                           # pass in init_container list
                           init_containers=[dsl.UserContainer('print', 'busybox:latest', command='echo "hello"')],
                           # pass in sidecars list
                           sidecars=[dsl.Sidecar('print', 'busybox:latest', command='echo "hello"')],
                           # pass in k8s container kwargs
                           container_kwargs={'env': [V1EnvVar('foo', 'bar')]},
       )
       # set `imagePullPolicy` property for `container` with `PipelineParam`
       op.container.set_image_pull_policy(pull_image_policy)
       # add sidecar with parameterized image tag
       # sidecar follows the argo sidecar swagger spec
       op.add_sidecar(dsl.Sidecar('redis', 'redis:%s' % tag).set_image_pull_policy('Always'))
  """

  # list of attributes that might have pipeline params - used to generate
  # the input parameters during compilation.
  # Excludes `file_outputs` and `outputs` as they are handled separately
  # in the compilation process to generate the DAGs and task io parameters.

  _DISABLE_REUSABLE_COMPONENT_WARNING = False

  def __init__(
      self,
      name: str,
      image: str,
      command: Optional[StringOrStringList] = None,
      arguments: Optional[StringOrStringList] = None,
      init_containers: Optional[List[UserContainer]] = None,
      sidecars: Optional[List[Sidecar]] = None,
      container_kwargs: Optional[Dict] = None,
      artifact_argument_paths: Optional[List[InputArgumentPath]] = None,
      file_outputs: Optional[Dict[str, str]] = None,
      output_artifact_paths: Optional[Dict[str, str]] = None,
      is_exit_handler: bool = False,
      pvolumes: Optional[Dict[str, V1Volume]] = None,
  ):
    super().__init__(name=name,
                     init_containers=init_containers,
                     sidecars=sidecars,
                     is_exit_handler=is_exit_handler)

    if (not ContainerOp._DISABLE_REUSABLE_COMPONENT_WARNING) and (
        '--component_launcher_class_path' not in (arguments or [])):
      # The warning is suppressed for pipelines created using the TFX SDK.
      warnings.warn(
          'Please create reusable components instead of constructing ContainerOp instances directly.'
          ' Reusable components are shareable, portable and have compatibility and support guarantees.'
          ' Please see the documentation: https://www.kubeflow.org/docs/pipelines/sdk/component-development/#writing-your-component-definition-file'
          ' The components can be created manually (or, in case of python, using kfp.components.create_component_from_func or func_to_container_op)'
          ' and then loaded using kfp.components.load_component_from_file, load_component_from_uri or load_component_from_text: '
          'https://kubeflow-pipelines.readthedocs.io/en/stable/source/kfp.components.html#kfp.components.load_component_from_file',
          category=FutureWarning,
      )

    self.attrs_with_pipelineparams = BaseOp.attrs_with_pipelineparams + [
        '_container', 'artifact_arguments', '_parameter_arguments'
    ]  #Copying the BaseOp class variable!

    input_artifact_paths = {}
    artifact_arguments = {}
    file_outputs = dict(file_outputs or {})  # Making a copy
    output_artifact_paths = dict(output_artifact_paths or {})  # Making a copy

    def resolve_artifact_argument(artarg):
      from ..components._components import _generate_input_file_name
      if not isinstance(artarg, InputArgumentPath):
        return artarg
      input_name = getattr(
          artarg.input, 'name',
          artarg.input) or ('input-' + str(len(artifact_arguments)))
      input_path = artarg.path or _generate_input_file_name(input_name)
      input_artifact_paths[input_name] = input_path
      artifact_arguments[input_name] = str(artarg.argument)
      return input_path

    for artarg in artifact_argument_paths or []:
      resolve_artifact_argument(artarg)

    if isinstance(command, Sequence) and not isinstance(command, str):
      command = list(map(resolve_artifact_argument, command))
    if isinstance(arguments, Sequence) and not isinstance(arguments, str):
      arguments = list(map(resolve_artifact_argument, arguments))

    # convert to list if not a list
    command = as_string_list(command)
    arguments = as_string_list(arguments)

    # `container` prop in `io.argoproj.workflow.v1alpha1.Template`
    container_kwargs = container_kwargs or {}
    self._container = Container(image=image,
                                args=arguments,
                                command=command,
                                **container_kwargs)

    # NOTE for backward compatibility (remove in future?)
    # proxy old ContainerOp callables to Container

    # attributes to NOT proxy
    ignore_set = frozenset(['to_dict', 'to_str'])

    # decorator func to proxy a method in `Container` into `ContainerOp`
    def _proxy(proxy_attr):
      """Decorator func to proxy to ContainerOp.container"""

      def _decorated(*args, **kwargs):
        # execute method
        ret = getattr(self._container, proxy_attr)(*args, **kwargs)
        if ret == self._container:
          return self
        return ret

      return deprecation_warning(_decorated, proxy_attr, proxy_attr)

    # iter thru container and attach a proxy func to the container method
    for attr_to_proxy in dir(self._container):
      func = getattr(self._container, attr_to_proxy)
      # ignore private methods, and bypass method overrided by subclasses.
      if (not hasattr(self, attr_to_proxy) and hasattr(func, '__call__') and
          (attr_to_proxy[0] != '_') and (attr_to_proxy not in ignore_set)):
        # only proxy public callables
        setattr(self, attr_to_proxy, _proxy(attr_to_proxy))

    if output_artifact_paths:
      warnings.warn(
          'The output_artifact_paths parameter is deprecated since SDK v0.1.32. '
          'Use the file_outputs parameter instead. file_outputs now supports '
          'outputting big data.', DeprecationWarning)

    # Special handling for the mlpipeline-ui-metadata and mlpipeline-metrics
    # outputs that should always be saved as artifacts
    # TODO: Remove when outputs are always saved as artifacts
    for output_name, path in dict(file_outputs).items():
      normalized_output_name = re.sub('[^a-zA-Z0-9]', '-', output_name.lower())
      if normalized_output_name in [
          'mlpipeline-ui-metadata', 'mlpipeline-metrics'
      ]:
        output_artifact_paths[normalized_output_name] = path
        del file_outputs[output_name]

    # attributes specific to `ContainerOp`
    self.input_artifact_paths = input_artifact_paths
    self.artifact_arguments = artifact_arguments
    self.file_outputs = file_outputs
    self.output_artifact_paths = output_artifact_paths or {}

    self._metadata = None
    self._parameter_arguments = None

    self.execution_options = _structures.ExecutionOptionsSpec(
        caching_strategy=_structures.CachingStrategySpec(),)

    self.outputs = {}
    if file_outputs:
      self.outputs = {
          name: _pipeline_param.PipelineParam(name, op_name=self.name)
          for name in file_outputs.keys()
      }

    # Syntactic sugar: Add task.output attribute if the component has a single
    # output.
    # TODO: Currently the "MLPipeline UI Metadata" output is removed from
    # outputs to preserve backwards compatibility. Maybe stop excluding it from
    # outputs, but rather exclude it from unique_outputs.
    unique_outputs = set(self.outputs.values())
    if len(unique_outputs) == 1:
      self.output = list(unique_outputs)[0]
    else:
      self.output = _MultipleOutputsError()

    self.pvolumes = {}
    self.add_pvolumes(pvolumes)

  # v2 container spec
  @property
  def container_spec(self):
    return self._container._container_spec

  @container_spec.setter
  def container_spec(self, spec: _PipelineContainerSpec):
    if not isinstance(spec, _PipelineContainerSpec):
      raise TypeError('container_spec can only be PipelineContainerSpec. '
                      'Got: {}'.format(spec))
    self._container._container_spec = spec

  @property
  def command(self):
    return self._container.command

  @command.setter
  def command(self, value):
    self._container.command = as_string_list(value)

  @property
  def arguments(self):
    return self._container.args

  @arguments.setter
  def arguments(self, value):
    self._container.args = as_string_list(value)

  @property
  def container(self):
    """`Container` object that represents the `container` property in `io.argoproj.workflow.v1alpha1.Template`. Can be used to update the container configurations.

    Example::

      import kfp.dsl as dsl
      from kubernetes.client.models import V1EnvVar

      @dsl.pipeline(name='example_pipeline')
      def immediate_value_pipeline():
        op1 = (dsl.ContainerOp(name='example', image='nginx:alpine')
                .container
                    .add_env_variable(V1EnvVar(name='HOST',
                    value='foo.bar'))
                    .add_env_variable(V1EnvVar(name='PORT', value='80'))
                    .parent # return the parent `ContainerOp`
                )
        """
    return self._container

  def _set_metadata(self, metadata):
    """Passes the ContainerOp the metadata information and configures the right output.

    Args:
      metadata (ComponentSpec): component metadata
    """
    if not isinstance(metadata, _structures.ComponentSpec):
      raise ValueError('_set_metadata is expecting ComponentSpec.')

    self._metadata = metadata

    if self.file_outputs:
      for output in self.file_outputs.keys():
        output_type = self.outputs[output].param_type
        for output_meta in self._metadata.outputs:
          if output_meta.name == output:
            output_type = output_meta.type
        self.outputs[output].param_type = output_type

  def add_pvolumes(self, pvolumes: Dict[str, V1Volume] = None):
    """Updates the existing pvolumes dict, extends volumes and volume_mounts and redefines the pvolume attribute.

    Args:
      pvolumes: Dictionary. Keys are mount paths, values are Kubernetes
        volumes or inherited types (e.g. PipelineVolumes).
    """
    if pvolumes:
      for mount_path, pvolume in pvolumes.items():
        if hasattr(pvolume, 'dependent_names'):
          self.dependent_names.extend(pvolume.dependent_names)
        else:
          pvolume = PipelineVolume(volume=pvolume)
        pvolume = pvolume.after(self)
        self.pvolumes[mount_path] = pvolume
        self.add_volume(pvolume)
        self._container.add_volume_mount(
            V1VolumeMount(name=pvolume.name, mount_path=mount_path))

    self.pvolume = None
    if len(self.pvolumes) == 1:
      self.pvolume = list(self.pvolumes.values())[0]
    return self

  def add_node_selector_constraint(self, label_name: str,
                                   value: str) -> 'ContainerOp':
    """Sets accelerator type requirement for this task.

    When compiling for v2, this function can be optionally used with
    set_gpu_limit to set the number of accelerator required. Otherwise, by
    default the number requested will be 1.

    Args:
      label_name: The name of the constraint label.
        For v2, only 'cloud.google.com/gke-accelerator' is supported now.
      value: The name of the accelerator.
        For v2, available values include 'nvidia-tesla-k80', 'tpu-v3'.

    Returns:
      self return to allow chained call with other resource specification.
    """
    if self.container_spec:
      accelerator_cnt = 1
      if self.container_spec.resources.accelerator.count > 1:
        # Reserve the number if already set.
        accelerator_cnt = self.container_spec.resources.accelerator.count

      accelerator_config = _PipelineContainerSpec.ResourceSpec.AcceleratorConfig(
          type=_sanitize_gpu_type(value), count=accelerator_cnt)
      self.container_spec.resources.accelerator.CopyFrom(accelerator_config)

    super(ContainerOp, self).add_node_selector_constraint(label_name, value)
    return self


# proxy old ContainerOp properties to ContainerOp.container
# with PendingDeprecationWarning.
ContainerOp = _proxy_container_op_props(ContainerOp)


class _MultipleOutputsError:

  @staticmethod
  def raise_error():
    raise RuntimeError(
        'This task has multiple outputs. Use `task.outputs[<output name>]` '
        'dictionary to refer to the one you need.')

  def __getattribute__(self, name):
    _MultipleOutputsError.raise_error()

  def __str__(self):
    _MultipleOutputsError.raise_error()


def _get_cpu_number(cpu_string: str) -> float:
  """Converts the cpu string to number of vCPU core."""
  # dsl.ContainerOp._validate_cpu_string guaranteed that cpu_string is either
  # 1) a string can be converted to a float; or
  # 2) a string followed by 'm', and it can be converted to a float.
  if cpu_string.endswith('m'):
    return float(cpu_string[:-1]) / 1000
  else:
    return float(cpu_string)


def _get_resource_number(resource_string: str) -> float:
  """Converts the resource string to number of resource in GB."""
  # dsl.ContainerOp._validate_size_string guaranteed that memory_string
  # represents an integer, optionally followed by one of (E, Ei, P, Pi, T, Ti,
  # G, Gi, M, Mi, K, Ki).
  # See the meaning of different suffix at
  # https://kubernetes.io/docs/concepts/configuration/manage-resources-containers/#meaning-of-memory
  # Also, ResourceSpec in pipeline IR expects a number in GB.
  if resource_string.endswith('E'):
    return float(resource_string[:-1]) * _E / _G
  elif resource_string.endswith('Ei'):
    return float(resource_string[:-2]) * _EI / _G
  elif resource_string.endswith('P'):
    return float(resource_string[:-1]) * _P / _G
  elif resource_string.endswith('Pi'):
    return float(resource_string[:-2]) * _PI / _G
  elif resource_string.endswith('T'):
    return float(resource_string[:-1]) * _T / _G
  elif resource_string.endswith('Ti'):
    return float(resource_string[:-2]) * _TI / _G
  elif resource_string.endswith('G'):
    return float(resource_string[:-1])
  elif resource_string.endswith('Gi'):
    return float(resource_string[:-2]) * _GI / _G
  elif resource_string.endswith('M'):
    return float(resource_string[:-1]) * _M / _G
  elif resource_string.endswith('Mi'):
    return float(resource_string[:-2]) * _MI / _G
  elif resource_string.endswith('K'):
    return float(resource_string[:-1]) * _K / _G
  elif resource_string.endswith('Ki'):
    return float(resource_string[:-2]) * _KI / _G
  else:
    # By default interpret as a plain integer, in the unit of Bytes.
    return float(resource_string) / _G


def _sanitize_gpu_type(gpu_type: str) -> str:
  """Converts the GPU type to conform the enum style."""
  return gpu_type.replace('-', '_').upper()
