Hera is a Python framework for constructing and submitting Argo Workflows.

Last update: Jan 2, 2023

Overview

Hera (hera-workflows)

The Argo was constructed by the shipwright Argus, and its crew were specially protected by the goddess Hera.

(https://en.wikipedia.org/wiki/Argo)

Hera is a Python framework for constructing and submitting Argo Workflows. The main goal of Hera is to make Argo Workflows more accessible by abstracting away some setup that is typically necessary for constructing Argo workflows.

Python functions are first class citizens in Hera - they are the atomic units (execution payload) that are submitted for remote execution. The framework makes it easy to wrap execution payloads into Argo Workflow tasks, set dependencies, resources, etc.

You can watch the introductory Hera presentation at the "Argo Workflows and Events Community Meeting 20 Oct 2021" here!

Table of content

Assumptions
Installation
Contributing
Concepts
Examples
Comparison

Assumptions

Hera is exclusively dedicated to remote workflow submission and execution. Therefore, it requires an Argo server to be deployed to a Kubernetes cluster. Currently, Hera assumes that the Argo server sits behind an authentication layer that can authenticate workflow submission requests by using the Bearer token on the request. To learn how to deploy Argo to your own Kubernetes cluster you can follow the Argo Workflows guide!

Another option for workflow submission without the authentication layer is using port forwarding to your Argo server deployment and submitting workflows to localhost:2746 (2746 is the default, but you are free to use yours). Please refer to the documentation of Argo Workflows to see the command for port forward!

In the future some of these assumptions may either increase or decrease depending on the direction of the project. Hera is mostly designed for practical data science purposes, which assumes the presence of a DevOps team to set up an Argo server for workflow submission.

Installation

There are multiple ways to install Hera:

You can install from PyPi:

pip install hera-workflows

Install it directly from this repository using:

python -m pip install git+https://github.com/argoproj-labs/hera-workflows --ignore-installed

Alternatively, you can clone this repository and then run the following to install:

python setup.py install

Contributing

If you plan to submit contributions to Hera you can install Hera in a virtual environment managed by pipenv:

pipenv shell
pipenv sync --dev --pre

Also, see the contributing guide!

Concepts

Currently, Hera is centered around two core concepts. These concepts are also used by Argo, which Hera aims to stay consistent with:

Task - the object that holds the Python function for remote execution/the atomic unit of execution;
Workflow - the higher level representation of a collection of tasks.

Examples

A very primitive example of submitting a task within a workflow through Hera is:

from hera.v1.task import Task
from hera.v1.workflow import Workflow
from hera.v1.workflow_service import WorkflowService


def say(message: str):
    """
    This can be anything as long as the Docker image satisfies the dependencies. You can import anything Python 
    that is in your container e.g torch, tensorflow, scipy, biopython, etc - just provide an image to the task!
    """
    print(message)


ws = WorkflowService('my-argo-domain.com', 'my-argo-server-token')
w = Workflow('my-workflow', ws)
t = Task('say', say, [{'message': 'Hello, world!'}])
w.add_task(t)
w.submit()

Examples

See the examples directory for a collection of Argo workflow construction and submission via Hera!

Comparison

There are other libraries currently available for structuring and submitting Argo Workflows:

Couler, which aims to provide a unified interface for constructing and managing workflows on different workflow engines;
Argo Python DSL, which allows you to programmaticaly define Argo worfklows using Python.

While the aforementioned libraries provide amazing functionality for Argo workflow construction and submission, they require an advanced understanding of Argo concepts. When Dyno Therapeutics started using Argo Workflows, it was challenging to construct and submit experimental machine learning workflows. Scientists and engineers at Dyno Therapeutics used a lot of time for workflow definition rather than the implementation of the atomic unit of execution - the Python function - that performed, for instance, model training.

Hera presents a much simpler interface for task and workflow construction, empowering users to focus on their own executable payloads rather than workflow setup. Here's a side by side comparison of Hera, Argo Python DSL, and Couler:

Hera	Couler	Argo Python DSL
from hera.v1.task import Task from hera.v1.workflow import Workflow from hera.v1.workflow_service import WorkflowService def say(message: str): print(message) ws = WorkflowService('my-argo-server.com', 'my-auth-token') w = Workflow('diamond', ws) a = Task('A', say, [{'message': 'This is task A!'}]) b = Task('B', say, [{'message': 'This is task B!'}]) c = Task('C', say, [{'message': 'This is task C!'}]) d = Task('D', say, [{'message': 'This is task D!'}]) a.next(b).next(d) # a >> b >> d a.next(c).next(d) # a >> c >> d w.add_tasks(a, b, c, d) w.submit()	B [lambda: job(name="A"), lambda: job(name="C")], # A -> C [lambda: job(name="B"), lambda: job(name="D")], # B -> D [lambda: job(name="C"), lambda: job(name="D")], # C -> D ] ) diamond() submitter = ArgoSubmitter() couler.run(submitter=submitter) "> import couler.argo as couler from couler.argo_submitter import ArgoSubmitter def job(name): couler.run_container( image="docker/whalesay:latest", command=["cowsay"], args=[name], step_name=name, ) def diamond(): couler.dag( [ [lambda: job(name="A")], [lambda: job(name="A"), lambda: job(name="B")], # A -> B [lambda: job(name="A"), lambda: job(name="C")], # A -> C [lambda: job(name="B"), lambda: job(name="D")], # B -> D [lambda: job(name="C"), lambda: job(name="D")], # C -> D ] ) diamond() submitter = ArgoSubmitter() couler.run(submitter=submitter)	V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="B") @dependencies(["A"]) def B(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="C") @dependencies(["A"]) def C(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="D") @dependencies(["B", "C"]) def D(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @template @inputs.parameter(name="message") def echo(self, message: V1alpha1Parameter) -> V1Container: container = V1Container( image="alpine:3.7", name="echo", command=["echo", "{{inputs.parameters.message}}"], ) return container "> from argo.workflows.dsl import Workflow from argo.workflows.dsl.tasks import * from argo.workflows.dsl.templates import * class DagDiamond(Workflow): @task @parameter(name="message", value="A") def A(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="B") @dependencies(["A"]) def B(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="C") @dependencies(["A"]) def C(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="D") @dependencies(["B", "C"]) def D(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @template @inputs.parameter(name="message") def echo(self, message: V1alpha1Parameter) -> V1Container: container = V1Container( image="alpine:3.7", name="echo", command=["echo", "{{inputs.parameters.message}}"], ) return container

Hera

Couler

Argo Python DSL

from hera.v1.task import Task
from hera.v1.workflow import Workflow
from hera.v1.workflow_service import WorkflowService


def say(message: str):
    print(message)


ws = WorkflowService('my-argo-server.com', 'my-auth-token')
w = Workflow('diamond', ws)
a = Task('A', say, [{'message': 'This is task A!'}])
b = Task('B', say, [{'message': 'This is task B!'}])
c = Task('C', say, [{'message': 'This is task C!'}])
d = Task('D', say, [{'message': 'This is task D!'}])

a.next(b).next(d)  # a >> b >> d
a.next(c).next(d)  # a >> c >> d

w.add_tasks(a, b, c, d)
w.submit()

B [lambda: job(name="A"), lambda: job(name="C")], # A -> C [lambda: job(name="B"), lambda: job(name="D")], # B -> D [lambda: job(name="C"), lambda: job(name="D")], # C -> D ] ) diamond() submitter = ArgoSubmitter() couler.run(submitter=submitter) ">

import couler.argo as couler
from couler.argo_submitter import ArgoSubmitter


def job(name):
    couler.run_container(
        image="docker/whalesay:latest",
        command=["cowsay"],
        args=[name],
        step_name=name,
    )


def diamond():
    couler.dag(
        [
            [lambda: job(name="A")],
            [lambda: job(name="A"), lambda: job(name="B")],  # A -> B
            [lambda: job(name="A"), lambda: job(name="C")],  # A -> C
            [lambda: job(name="B"), lambda: job(name="D")],  # B -> D
            [lambda: job(name="C"), lambda: job(name="D")],  # C -> D
        ]
    )


diamond()
submitter = ArgoSubmitter()
couler.run(submitter=submitter)

V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="B") @dependencies(["A"]) def B(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="C") @dependencies(["A"]) def C(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @task @parameter(name="message", value="D") @dependencies(["B", "C"]) def D(self, message: V1alpha1Parameter) -> V1alpha1Template: return self.echo(message=message) @template @inputs.parameter(name="message") def echo(self, message: V1alpha1Parameter) -> V1Container: container = V1Container( image="alpine:3.7", name="echo", command=["echo", "{{inputs.parameters.message}}"], ) return container ">

from argo.workflows.dsl import Workflow

from argo.workflows.dsl.tasks import *
from argo.workflows.dsl.templates import *


class DagDiamond(Workflow):

    @task
    @parameter(name="message", value="A")
    def A(self, message: V1alpha1Parameter) -> V1alpha1Template:
        return self.echo(message=message)

    @task
    @parameter(name="message", value="B")
    @dependencies(["A"])
    def B(self, message: V1alpha1Parameter) -> V1alpha1Template:
        return self.echo(message=message)

    @task
    @parameter(name="message", value="C")
    @dependencies(["A"])
    def C(self, message: V1alpha1Parameter) -> V1alpha1Template:
        return self.echo(message=message)

    @task
    @parameter(name="message", value="D")
    @dependencies(["B", "C"])
    def D(self, message: V1alpha1Parameter) -> V1alpha1Template:
        return self.echo(message=message)

    @template
    @inputs.parameter(name="message")
    def echo(self, message: V1alpha1Parameter) -> V1Container:
        container = V1Container(
            image="alpine:3.7",
            name="echo",
            command=["echo", "{{inputs.parameters.message}}"],
        )

        return container

Comments

CICD Improvements
About

this is a work in progress; it aims to check feasibility for further discussion

Following #93, further improve CI + CD

Tasks

[x] add coverage reports tasks and ci

[x] store all py vers X OS coverage files

[x] combine all py vers X OS coverage files

[x] create html cov

[x] store coverage report artifact

[x] add optional binary distribution to wheels via setup.py

[x] add a none-any build just in case and publish it

[x] add sdist build ( .tar.gz ) build for publishing

[x] store built wheels by tox

reason for publishing to tested wheels

[x] build wheels for all distributions ( matrix = py ver + os )

[x] build py3-none-any wheel + sdist ( .tar.gz )

[x] consolidation hera CICD into a single gh workflow

motivation re-use test / build job as a pre-publishing job

motivation to leverage artifacts passing between jobs rather than between different workflows

[x] add publish job ( similar to exiting one )

[x] change event triggers

[x] add if: to publish job

[x] delete file .github/workflows/hera_build_and_publish.yaml

[x] rename file .github/workflows/hera_pr.yaml -> .github/workflows/cicd.yaml ( or .. )

[x] fix jobs badge workflow name hera_build_and_publish.yaml -> cicd.yaml ( or .. ) in README.md

[x] enable upload to pypi-test for the purpose of validating entire publish job ( see publish job failure )

[x] replace upload to pypi-test with upload to pypi in publish job

[ ] setup codecov if we want a coverage badge to be introduced in this PR ( or propose a different solution )

inspiration credit https://github.com/samuelcolvin/pydantic/blob/master/.github/workflows/ci.yml
opened by harelwa 21
Add context management for workflow submission
Currently, users have to add tasks to a workflow independently. After a task is defined, it is necessary to call workflow.add_tasks(t1, t2, ...) for otherwise the tasks are not added to the template of the DAG in the main workflow. To save some effort in this arena, a context manager can be introduced to auto-insert tasks into a workflow, and submit a workflow during the exit phase of the context. This will provide two ways of adding tasks to a workflow.

Current, and supported way of adding tasks and submitting a workflow:

wf = Workflow('test') t1 = Task('t1', image='docker/whalesay', command=['cowsay', 'foo']) t2 = Task('t2', image='docker/whalesay', command=['cowsay', 'foo']) t1 >> t2 wf.add(t1, t2) wf.submit()

Potential future (second) way of adding tasks and submitting a workflow:

with Workflow('test') as wf: Task('t1', image='docker/whalesay', command=['cowsay', 'foo']) >> Task('t2', image='docker/whalesay', command=['cowsay', 'foo'])

Alternatively:

with Workflow('test') as wf: t1 = Task('t1', image='docker/whalesay', command=['cowsay', 'foo']) t2 = Task('t2', image='docker/whalesay', command=['cowsay', 'foo']) t1 >> t2

This will require the implementation of a context manager on Workflow and a container for Task, which tasks insert themselves into during __init__:

class Workflow: def __enter__(self, ...): ... return self def __exit__(self, ...): ... return self.submit() class _Container(list): @classmethod def add(cls, t: Task): cls.append(t) class Task: def __init__(...): ... _Container.add(self)

Questions to consider:

Does this solve a real problem or would it cause confusion because of of the implicit behavior of task additions?

Is this an interface that abides by Hera's principle of simplicity? Is the _Container usage a bit too abstract?

Is it safe to assume that exiting a context should indeed submit a workflow? If not but the design is something desirable, should users be provided with the feature, along with a parameter on Workflow that says "auto_submit? Does that pollute the interface ofWorkflow` unnecessarily with QOL features rather than focusing on exposing Argo specific parameters?

Would love to discuss this @bchalk101 and @bobh66! Any thoughts? Would this be useful to your use case?
enhancement
opened by flaviuvadan 20
Multiple Python Versions CI
Purpose of PR

related issues and PRs #73 #92 #94

Provide multiple python versions CI ( CD will be handled in a different PR )

To achieve this, introduce usage of tox for testing built wheels in "isolated envs" of multiple python versions.

Notes regarding similar open PRs

The difference between this PR and #92 is that it does not run pipenv in tox, but rather lets tox handle dependencies and venvs

The difference between this PR and #94 that it keep pipenv as the project's dev env manager

Tasks

[x] add tox.ini with python{3.7,3.8,3.9,3.10} test envs

[x] add build matrix of python versions to ci

ref docs: https://docs.github.com/en/actions/using-workflows/advanced-workflow-features#using-a-build-matrix

ref proj: https://github.com/spotify/luigi/

ref proj: https://github.com/samuelcolvin/pydantic/

[x] remove caching of Pipfile.lock

Pipfile.lock is a py37 lock file

[x] for dev purposes, update Pipfile and Pipfile.lock

for ci, tox is used directly as Pipfile.lock is a py37 lock file

Notes for future changes

Evaluate usage of pipenv in tox 1.1 See https://pipenv-fork.readthedocs.io/en/latest/advanced.html#tox-automation-project 1.2 Evaluate tox-pipenv

Evaluate poetry to replace pipenv 2.1 See #94 2.2 See related discussion of "who does what and why" regarding tox and poetry: https://github.com/python-poetry/poetry/discussions/4307

Changes to Pipfile

To use tox, it was added to pipfile as a dev dependency, with the following command:

pipenv install pytest-cov "tox<4.0" tox-wheel --dev

tox-wheel was added as well to make tox build wheels rather than zip, so these can be used for publishing [ more below ].

After running tox, you'll find the wheels under .tox/dist:

❯ ls .tox/dist hera_workflows-1.8.0rc7-py3-none-any.whl

pytest-cov was added as well so we can add a coverage reports and tests, and perhaps add a coverage test.

Even though this might be related to a different PR, I think it's also related to this PR as well, as it concerns major changes to how hera is tested. In this context, I've added the relevant pytest opt in setup.cfg.

More on added tox.ini

To use tox update / recreate your pipenv virtual env according to the updated Pipfile

An initial tox.ini was created with a few tox envs.

The "main" env - testenv -- provides the first desired functionality discussed in #73 and tests 4 python versions, including 3.10 ( latest ).

To list all tox envs you can run:

❯ tox -a python3.7 python3.8 python3.9 python3.10 lint typecheck

And to run a specific one, e.g. lint, run -

❯ tox -e lint
opened by harelwa 15

Unable to resolve methods outside script

Hi there, I'm new to Hera and Argo so bear with me if the question is rookie:

Here is my code snippet:

from app.common.image.image_utils import read_image
from app.common.models.thumbnail_metadata import ThumbnailMetadata
from app.common.s3_utils import resolve_s3_url, upload
from app.common.tasks.argo_task import ArgoTask
from app.services.argo_client import ArgoWorkflowService

class ThumbnailTask(ArgoTask):
    def __init__(self, metadata: ThumbnailMetadata):
        # .... some more code

    def create_thumbnails(self, image_url: str, thumbnail_sizes: list[dict]):
        blob = read_image(self.image_url)

        # .... some more code

    def create(self):
        ArgoWorkflowService.create_task('create_thumbnails', ThumbnailTask.create_thumbnails, [{
            'image_url': self.image_url,
            'thumbnail_sizes': self.thumbnail_sizes
        }])

from typing import Callable
from hera.retry import Retry
from hera.task import Task
from hera.workflow import Workflow
from hera.workflow_service import WorkflowService

from app.core.config import get_app_settings

class ArgoWorkflowService(object):
    workflow_service = None
    workflow = None

    @staticmethod
    def create_task(name: str, func: Callable, func_params: list[dict]):
        # .... some more code

        task = Task(name, func, func_params, image='my-repo.dkr.ecr.us-east-2.amazonaws.com/my-app:latest', retry=Retry(duration=3, max_duration=60))
        ArgoWorkflowService.workflow.add_task(task)
        ArgoWorkflowService.workflow.create()

The error I received in Argo is:

│ main Traceback (most recent call last):                                                                                                                                                                                         │
│ main   File "/argo/staging/script", line 5, in <module>                                                                                                                                                                         │
│ main     blob = read_image(self.image_url)                                                                                                                                                                                      │
│ main NameError: name 'read_image' is not defined                                                                                                                                                                                │
│

The method read_image is from other packages.

In addition, Argo was unable to import 3rd party python libraries. I used the same application image but still not working.

Any help would be appreciated!

question

opened by linyaoli 14

How to create a workflow with 10k tasks
I'd like to have a workflow with many tasks, but I'm running into the 1.5MB k8s/etcd file limit. The workflow isn't complicated, it's basically 10k very-short bash commands that all run on the same image with the same resources etc.

I think the solution here is to use a WorkflowTemplate, but I haven't figured out how to use input parameters with hera.

I have something like this:

# set up the WorkflowTemplate wt = WorkflowTemplate(...) # is this the right way to pass input in? t = Task("cmd", lambda: _, command=["bash", "-c", "{{inputs.parameters.cmd}}"], ...) wt.add_task(t) wt.create() # how do I get these commands into the workflow as parameters? commands = ["echo foo", "echo bar"] # create the Workflow workflow = Workflow(..., workflow_template_ref=wt.name) workflow.create()
question stale
opened by dmerrick 13

How to ignore certificate errors?

When I attempt to port-forward Argo running in GKE, I get a certificate error. I tried the suggestion from the first comment here, but I still get the certificate error.

C:\Users\ryanr\Code\hera-workflows\examples [main ≡ +0 ~1 -0 !]> python .\diamond.py
Traceback (most recent call last):
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 706, in urlopen      
    chunked=chunked,
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 382, in _make_request
    self._validate_conn(conn)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 1010, in _validate_conn
    conn.connect()
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connection.py", line 426, in connect
    tls_in_tls=tls_in_tls,
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\util\ssl_.py", line 450, in ssl_wrap_socket
    sock, context, tls_in_tls, server_hostname=server_hostname
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\util\ssl_.py", line 493, in _ssl_wrap_socket_impl
    return ssl_context.wrap_socket(sock, server_hostname=server_hostname)
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.7_3.7.2544.0_x64__qbz5n2kfra8p0\lib\ssl.py", line 423, in wrap_socket
    session=session
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.7_3.7.2544.0_x64__qbz5n2kfra8p0\lib\ssl.py", line 870, in _create
    self.do_handshake()
  File "C:\Program Files\WindowsApps\PythonSoftwareFoundation.Python.3.7_3.7.2544.0_x64__qbz5n2kfra8p0\lib\ssl.py", line 1139, in do_handshake
    self._sslobj.do_handshake()
ssl.SSLCertVerificationError: [SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1091)

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File ".\diamond.py", line 32, in <module>
    w.submit()
  File "c:\users\ryanr\code\hera-workflows\src\hera\v1\workflow.py", line 129, in submit
    self.service.submit(self.workflow, namespace)
  File "c:\users\ryanr\code\hera-workflows\src\hera\v1\workflow_service.py", line 48, in submit
    return self.service.create_workflow(namespace, V1alpha1WorkflowCreateRequest(workflow=workflow))
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\api\workflow_service_api.py", line 62, in create_workflow
    return self.create_workflow_with_http_info(namespace, body, **kwargs)  # noqa: E501
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\api\workflow_service_api.py", line 162, in create_workflow_with_http_info
    collection_formats=collection_formats)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\api_client.py", line 369, in call_api
    _preload_content, _request_timeout, _host)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\api_client.py", line 185, in __call_api
    _request_timeout=_request_timeout)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\api_client.py", line 413, in request
    body=body)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\rest.py", line 271, in POST
    body=body)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\argo\workflows\client\rest.py", line 168, in request
    headers=headers)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\request.py", line 79, in request
    method, url, fields=fields, headers=headers, **urlopen_kw
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\request.py", line 170, in request_encode_body
    return self.urlopen(method, url, **extra_kw)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\poolmanager.py", line 375, in urlopen
    response = conn.urlopen(method, u.request_uri, **kw)
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 796, in urlopen
    **response_kw
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 796, in urlopen
    **response_kw
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 796, in urlopen
    **response_kw
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\connectionpool.py", line 756, in urlopen
    method, url, error=e, _pool=self, _stacktrace=sys.exc_info()[2]
  File "C:\Users\ryanr\.virtualenvs\hera-workflows-FA8T1hb6\lib\site-packages\urllib3\util\retry.py", line 574, in increment
    raise MaxRetryError(_pool, url, error or ResponseError(cause))
urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='localhost', port=2746): Max retries exceeded with url: /api/v1/workflows/default (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1091)')))

opened by tachyus-ryan 13

Support latest Python version

Hi! Thank you for developing such a great tool! Currently, Hera supports only Python 3.7. The version is now security status, will become end of support soon.

reference: https://www.python.org/downloads/

So it is better that supporting Python 3.8+, IMO. I'm happy to create PR for supporting newer version of Python, if it is OK.

Thank you.
enhancement

opened by hirosassa 12
Bugfix: env value_from_input was ignored

In case of Env being specified via value_from_input, the actual value of the value_from_input is ignored and just its not-Noneness is checked. We fix it here to use it. Current buggy state has the unfortunate consequence of having to name the env var the same as the parameter

opened by tmi 11

Add task template mechanism

Description

This MR provides additional funcitonality for templating tasks with a class TaskTemplate.

Example

task_template = TaskTemplate('myTemplate', say,
    [{
        'message': "default value for param 'message'",
        "other_message": {"default": {"value": {"for": "other_message"}}},
    }],
)
a = task_template.task("taskWithDefaultValues")
b = task_template.task("taskWithNonDefaultValues", [{"other_message": "hello again"}])

opened by kromanow94 10

How about supporting onExit?

Argo Workflows provides a function, onExit, to execute a template after the workflow has finished. https://github.com/argoproj/argo-workflows/blob/master/examples/exit-handlers.yaml

How about supporting onExit for hera-workflows as well? I have tested the following implementation.

class WorkflowWithOnExit(Workflow):
    def __init__(self, name: str, service: WorkflowService, **kw):
        super().__init__(name, service, **kw)

    def add_tasks_on_exit(self, on_exit_task: "OnExitTask", *ts: Task) -> None:
        template_on_exit_name = self.name + "-onExit"
        setattr(self.spec, "on_exit", template_on_exit_name)

        # prepare template for onExit
        dag_template_on_exit = IoArgoprojWorkflowV1alpha1DAGTemplate(tasks=[])
        template_on_exit = IoArgoprojWorkflowV1alpha1Template(
            name=template_on_exit_name,
            steps=[],
            dag=dag_template_on_exit,
            parallelism=self.parallelism,
        )
        self.spec.templates.append(template_on_exit)

        # HACK: Not using workflow_editors.add_tasks to add to dag_template_on_exit.tasks
        for t in (on_exit_task,) + ts:
            self.spec.templates.append(t.argo_template)
            if t.resources.volumes:
                for vol in t.resources.volumes:
                    if isinstance(vol, Volume):
                        self.spec.volume_claim_templates.append(vol.get_claim_spec())
                    else:
                        self.spec.volumes.append(vol.get_volume())
            dag_template_on_exit.tasks.append(t.argo_task)


class OnExitTask(Task):
    def when_by_workflow_status(
        self, operator: Operator, workflow_status: WorkflowStatus
    ):
        self.argo_task.when = (
            f"{{{{workflow.status}}}} {operator.value} {workflow_status.value}"
        )

def f_with_error():
    raise RuntimeError("Err!")


def exit_handler():
    print("exit_handler")


def exit_handler_next():
    print("exit_handler_next")

ws = WorkflowService(
    host=host,
    token=token,
    namespace=namespace,
)

w = WorkflowWithOnExit(
    "test_exit_handler",
    ws,
    namespace=namespace,
    service_account_name=service_account,
)

task_exit_handler = OnExitTask("exit_handler", exit_handler, image=image)
task_exit_handler.when_by_workflow_status(Operator.not_equal, WorkflowStatus.Succeeded)
task_exit_handler_next = Task("exit_handler_next", exit_handler_next, image=image)
task_exit_handler >> task_exit_handler_next

task_with_error = Task("task_with_error", f_with_error, image=image)

w.add_tasks(task_with_error)
w.add_tasks_on_exit(task_exit_handler, task_exit_handler_next)

w.create()

STEP                         TEMPLATE                  PODNAME                       DURATION  MESSAGE
 ✖ test-exit-handler         test-exit-handler
 └─✖ task-with-error         task-with-error           test-exit-handler-153195892   12s       Error (exit code 1)

 ✔ test-exit-handler.onExit  test-exit-handler-onExit
 ├─✔ exit-handler            exit-handler              test-exit-handler-2402822171  10s
 └─✔ exit-handler-next       exit-handler-next         test-exit-handler-2592397439  10s

enhancement

opened by szdr 10

Support multiple python using tox with Poetry

fix #73

What is this PR?

Related to #93, I implemented support for multiple Python versions using tox. Different from #93, this PR uses Poetry as a package management to simplify configurations of linters, tests and builds.

opened by hirosassa 10
SSL: CERTIFICATE_VERIFY_FAILED

Hello I am try to submit flow to argo with the following codes: argo-workflows 6.3.5

from hera import Task, Workflow from hera import global_config

global_config.GlobalConfig.host = xxx global_config.GlobalConfig.token = xxx global_config.GlobalConfig.verify_ssl = False

def say(message: str): print(message)

with Workflow("diamond") as w: a = Task('a', say, ['This is task A!']) b = Task('b', say, ['This is task B!']) c = Task('c', say, ['This is task C!']) d = Task('d', say, ['This is task D!']) a >> [b, c] >> d

w.create()

when i run this scrpt , i got the following error: urllib3.exceptions.MaxRetryError: HTTPSConnectionPool(host='xxx', port=xxx): Max retries exceeded with url: /api/v1/workflows/default (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: unable to get local issuer certificate (_ssl.c:1131)')))

My question is why i get a ssl error after i set global_config.GlobalConfig.verify_ssl = False?

It seems that set ssl by GlobalConfig is not work...

And i try to change the source code of hera/workflow_service.py: class WorkflowService: def init( self, host: Optional[str] = None, verify_ssl: bool = False, # change True to False token: Optional[str] = None, namespace: Optional[str] = None, ): After i change the default value of verify_ssl from True to False, i can submit to Argo server successfully.

So is it a bug or something that global_config.GlobalConfig.verify_ssl does not affect "WorkflowService"'s verify_ssl?

Thanks

opened by xuanbo241 4

Custom image and inter task communication

I am facing the issue of not being able to load pickle files from the task that previously saved them. My assumption is it has to do something with the custom image because the example by hera runs without any problems. Any ideas? Here is my code:

from hera import Artifact, ImagePullPolicy
from hera.task import Task
from hera.workflow import Workflow
from hera.workflow_service import WorkflowService


def task_cleaned_data_housing(data_url):
    import pathlib
    import pickle

    import data_housing_pipeline_module

    data_url = str(data_url)

    training_data = data_housing_pipeline_module.get_cleaned_data_housing(
        data_url
    )

    if not pathlib.Path("/tmp").joinpath("data_housing_pipeline").exists():
        pathlib.Path("/tmp").joinpath("data_housing_pipeline").mkdir()
    pickle.dump(
        training_data,
        open("/tmp/data_housing_pipeline/variable_training_data.pickle", "wb"),
    )


def task_linear_model_housing():
    import pathlib
    import pickle

    import data_housing_pipeline_module

    training_data = pickle.load(
        open("/tmp/data_housing_pipeline/variable_training_data.pickle", "rb")
    )

    linear_model = data_housing_pipeline_module.get_linear_model_housing(
        training_data
    )

    if not pathlib.Path("/tmp").joinpath("data_housing_pipeline").exists():
        pathlib.Path("/tmp").joinpath("data_housing_pipeline").mkdir()
    pickle.dump(
        linear_model,
        open("/tmp/data_housing_pipeline/variable_linear_model.pickle", "wb"),
    )


ws = WorkflowService(
    host="https://localhost:2746",
    verify_ssl=False,
    token="None",
    namespace="argo",
)

with Workflow("data-housing-pipeline", service=ws) as w:

    cleaned_data_housing = Task(
        "cleaned-data-housing",
        task_cleaned_data_housing,
        [
            {
                "data_url": "https://raw.githubusercontent.com/LineaLabs/lineapy/main/examples/use_cases/predict_house_price/data/ames_train_cleaned.csv",
            }
        ],
        image="argo_pipeline:latest",
        image_pull_policy=ImagePullPolicy.Never,
        outputs=[
            Artifact(
                "training_data",
                "/tmp/data_housing_pipeline/variable_training_data.pickle",
            ),
        ],
    )

    linear_model_housing = Task(
        "linear-model-housing",
        task_linear_model_housing,
        image="argo_pipeline:latest",
        image_pull_policy=ImagePullPolicy.Never,
        inputs=[cleaned_data_housing.get_artifact("training_data")],
        outputs=[
            Artifact(
                "linear_model",
                "/tmp/data_housing_pipeline/variable_linear_model.pickle",
            ),
        ],
    )

    cleaned_data_housing >> linear_model_housing

w.create()

The message I get is: Unable to resolve: "tasks.cleaned-data-housing.outputs.artifacts.training_data"

opened by lazargugleta 2

Fix name validation, add support for generate_name
While browsing through the code, I spotted an issue in validate_name in that it uses re.match (match the beginning of the string) rather than re.fullmatch (match the whole string). One thing led to another, and I found and fixed a couple more bugs, and added a new parameter for proper validation of metadata.generateName.

Names in k8s cannot end in hyphen "-" or period ".", however the same is a valid choice for metadata.generateName. I have extended validate_name with an optional generate_name parameter to support this, synchronized with the identical parameter of workflow.__init__.

Changes

Validate entire name in validate_name, not only the beginning of the string

Without this, the invalid name "test#" would unexpectedly pass validation.

Fix quoting of "." in pattern used in validate_name

Without this, the invalid name r"test\@" would unexpectedly pass validation

Add a new generate_name boolean parameter, default to False; if True, a name ending in a single period "." or any number of hyphens "-" will pass validation, as alphanumeric characters are expected to be appended in the final name

Without this, the valid generate name "test-" would unexpectedly fail validation

Strip trailing "-" and "." characters when workflow name is reused for an unnamed dag

Without this, the valid generate name "test-" would result in a validation error if the dag is not named explicitly
opened by tachylatus 4
Multitask Dag

Hi,

I was wondering if there is an example of how to create complex workflows.

I would like to create a workflow similar to this one, but I haven\t figured out how to specify the steps when I'm creating the workflow.

Thanks for the help,

question

opened by alejoGT1202 2
Feature request: support for archivelog

It appears argo supports setting archive log on the Workflow spec and template. It would be nice to have this supported in hera.

https://argoproj.github.io/argo-workflows/configure-archive-logs/
enhancement

opened by ipl31 0

Owner

argoproj-labs

GitHub

WATTS provides a set of Python classes that can manage simulation workflows for multiple codes where information is exchanged at a coarse level

WATTS (Workflow and Template Toolkit for Simulation) provides a set of Python classes that can manage simulation workflows for multiple codes where information is exchanged at a coarse level.