![argo-logo](../_static/services/argo_workflows_logo.png)

# How to use Argo Workflows

## Prerequisites

Request access to Argo Workflows by contacting [support@eodc.eu](mailto:support@eodc.eu). You will receive a token required to authenticate. Mention in your request if you intend to use the eodc SDK.

## Install

```
pip install eodc hera-workflows
```

## Configure the connection

Before submitting any workflow, set the three required settings:

```python
import eodc
from eodc.settings import settings

settings.FAAS_URL = "https://services.eodc.eu/workflows/"
settings.NAMESPACE = "default"
settings.ARGO_WORKFLOWS_TOKEN = ""  # your token here
```

Then create a service client:

```python
service = eodc.faas.CustomWorkflow(
    processor_details=eodc.faas.FaasProcessor.custom
)
```

## Submit a container-based workflow

The most common use case is running an existing Docker image across your data. Use a `Container` template to specify the image and command:

```python
from hera.workflows import Container, Parameter, Step, Steps, Workflow

def my_workflow(workflows_service):
    with Workflow(
        workflows_service=workflows_service,
        namespace=workflows_service.namespace,
        generate_name="eo-processing-",
        entrypoint="steps",
    ) as w:
        process = Container(
            name="process",
            image="registry.eodc.eu/my-org/my-processor:latest",
            command=["python", "run.py"],
        )

        with Steps(name="steps"):
            Step(
                name="run-processor",
                template=process,
                arguments=[Parameter(name="input", value="s3://my-bucket/input/")],
            )
    return w

name = service.submit_workflow(
    workflow=my_workflow(service.workflows_service)
)
print(f"Submitted: {name}")
```

1. `Container(image=..., command=...)` — defines the Docker image and entrypoint. The image must be accessible from the eodc container registry or a public registry.
2. `generate_name` — used as a prefix for the workflow instance name. The full name is returned by `submit_workflow`.
3. `Step(arguments=[Parameter(...)])` — passes runtime arguments into the container.
4. `service.submit_workflow(...)` — submits the workflow to the eodc Argo cluster and returns the workflow name.

## Submit a multi-step workflow with parallel steps

For workflows with sequential and parallel stages, use `s.parallel()` to group steps that run concurrently:

```python
from hera.workflows import Container, Step, Steps, Workflow

def pipeline(workflows_service):
    with Workflow(
        workflows_service=workflows_service,
        namespace=workflows_service.namespace,
        generate_name="pipeline-",
        entrypoint="steps",
    ) as w:
        task = Container(
            name="task",
            image="busybox",
            command=["echo"],
        )

        with Steps(name="steps") as s:
            Step(name="prepare", template=task,
                 arguments=[Parameter(name="message", value="preparing")])
            with s.parallel():
                Step(name="process-a", template=task,
                     arguments=[Parameter(name="message", value="tile-A")])
                Step(name="process-b", template=task,
                     arguments=[Parameter(name="message", value="tile-B")])
            Step(name="merge", template=task,
                 arguments=[Parameter(name="message", value="merging results")])
    return w

name = service.submit_workflow(
    workflow=pipeline(service.workflows_service)
)
```

## Monitor and get logs

After submitting, retrieve logs programmatically:

```python
service.get_logs(name)
```

To monitor visually, open the Argo dashboard — see [Using the dashboard](../services/argo-workflows#using-the-dashboard) for a walkthrough with screenshots.

## Tips

- Workflows can read from and write to the [eodc Object Store](../services/objectstore) — useful for passing data between steps and storing results.
- For scheduled processing (daily runs, etc.), use Argo's CronWorkflow resource. Contact [support@eodc.eu](mailto:support@eodc.eu) for help setting one up.
- For a full tutorial series on Argo Workflows with Hera, see the [Argo Workflows SDK notebook](../notebooks/argo-sdk).