Hera is a Python framework for constructing and submitting Argo Workflows. The main goal of Hera is to make the Argo ecosystem accessible by simplifying workflow construction and submission.
See the Quick Start guide to start using Hera to orchestrate your Argo Workflows!
The Argo was constructed by the shipwright Argus,
and its crew were specially protected by the goddess Hera.
from hera.workflows import Steps, Workflow, script
@script()
def echo(message: str):
print(message)
with Workflow(
generate_name="single-script-",
entrypoint="steps",
) as w:
with Steps(name="steps") as s:
echo(name="A", arguments={"message": "I'm a step"})
with s.parallel():
echo(name="B", arguments={"message": "We're steps"})
echo(name="C", arguments={"message": "in parallel!"})
echo(name="D", arguments={"message": "I'm another step!"})
w.create()
from hera.workflows import DAG, Workflow, script
@script()
def echo(message: str):
print(message)
with Workflow(
generate_name="dag-diamond-",
entrypoint="diamond",
) as w:
with DAG(name="diamond"):
A = echo(name="A", arguments={"message": "A"})
B = echo(name="B", arguments={"message": "B"})
C = echo(name="C", arguments={"message": "C"})
D = echo(name="D", arguments={"message": "D"})
A >> [B, C] >> D
w.create()
See the examples for a collection of Argo workflow construction and submission via Hera!
Hera 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 change it). Please
refer to the documentation of Argo Workflows to see the
command for port forward!
Note Since the deprecation of tokens being automatically created for ServiceAccounts and Argo using Bearer tokens in place, it is necessary to use
--auth=server
and/or--auth=client
when setting up Argo Workflows on Kubernetes v1.24+ in order for hera to communicate to the Argo Server.
There are a few ways to authenticate in Hera - read more in the
authentication walk through - for now, with the
argo
cli tool installed, this example will get you up and running:
from hera.workflows import Workflow, Container
from hera.shared import global_config
from hera.auth import ArgoCLITokenGenerator
global_config.host = "http://localhost:2746"
global_config.token = ArgoCLITokenGenerator
with Workflow(generate_name="local-test-", entrypoint="c") as w:
Container(name="c", image="docker/whalesay", command=["cowsay", "hello"])
w.create()
Note Hera went through a name change - from
hera-workflows
tohera
. This is reflected in the published Python package. If you'd like to install versions prior to5.0.0
, you have to usehera-workflows
. Hera currently publishes releases to bothhera
andhera-workflows
for backwards compatibility purposes.
Source | Command |
---|---|
PyPi | pip install hera |
PyPi | pip install hera-workflows |
GitHub repo | python -m pip install git+https://github.com/argoproj-labs/hera --ignore-installed; pip install . |
yaml
hera[yaml]
yaml
output format, which is accessible via
hera.workflows.Workflow.to_yaml(*args, **kwargs)
. This enables GitOps practices and easier debugging.cli
hera[cli]
. The [cli]
option installs the extra dependency Cappa
required for the CLIhera generate yaml
. See hera generate yaml --help
for more information.experimental
hera[experimental]
. The [experimental]
option adds dependencies required for experimental features that have not yet graduated into stable features.See the contributing guide!