> ## Documentation Index
> Fetch the complete documentation index at: https://notes.kodekloud.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Template Invocators Types Steps
> Describes Argo Workflows Steps templates demonstrating sequential step-groups and parallel steps using a cowsay example with reusable templates and parameter passing
Explore the Steps template invoker type in Argo Workflows. Steps templates let you compose multi-step workflows that run tasks both sequentially and in parallel. This example workflow, named "Cosmic Move", shows how a Steps template orchestrates reusable templates (here, `cow-says`) into a sequence of step groups with parallel execution inside groups.
```yaml theme={null}
apiVersion: argoproj.io/v1alpha1
kind: Workflow
metadata:
generateName: cosmic-moo-
spec:
entrypoint: triple-moo
templates:
- name: triple-moo
steps:
- - name: first-moo
template: cow-says
arguments:
parameters:
- name: message
value: "Cosmic Ranch!"
- - name: parallel-moo-a
template: cow-says
arguments:
parameters:
- name: message
value: "Galaxy Moo!"
- name: parallel-moo-b
template: cow-says
arguments:
parameters:
- name: message
value: "Milky Whey!"
- name: cow-says
inputs:
parameters:
- name: message
container:
image: rancher/cowsay
command: ["cowsay"]
args: ["{{inputs.parameters.message}}"]
```
How this workflow is wired:
* The workflow entrypoint is `triple-moo`.
* `triple-moo` uses a `steps` block to orchestrate calls to the reusable `cow-says` template.
* `cow-says` is a simple container task that runs `cowsay` with the supplied `message` parameter.
Understanding the `steps` structure
* `steps` is a list of step-groups (a list of lists).
* Each top-level list item (each top-level `-`) is a step-group that executes in sequence.
* Within a step-group, each inner `-` is an individual step that runs in parallel with the other inner steps in that group.
Think of `steps` as a sequence of step-groups: each top-level dash creates a group that runs one after another; steps inside the same group (inner dashes) run concurrently.
Execution semantics (summary):
* Top-level elements (step-groups) run one after another (sequential).
* Inner list elements inside a group run at the same time (parallel).
* The workflow advances to the next group only after every step in the current group finishes.
Example: what happens in the "Cosmic Move" workflow
* First step-group:
* `first-moo` runs by itself. The workflow waits until it completes.
* Second step-group:
* `parallel-moo-a` and `parallel-moo-b` run concurrently. The workflow proceeds only after both finish.
When you inspect a running workflow with argo, the execution tree shows the sequence and parallel steps. Example output:
```console theme={null}
$ argo -n argo get cosmic-moo-k2kxq
STEP TEMPLATE PODNAME
✓ cosmic-moo-k2kxq triple-moo
├─✓ first-moo cow-says cosmic-moo-k2kxq-cow-says-2575730875
├─✓ parallel-moo-a cow-says cosmic-moo-k2kxq-cow-says-1190566453
└─✓ parallel-moo-b cow-says cosmic-moo-k2kxq-cow-says-1140233596
```
Quick reference table
| Concept | Behavior | Example |
| ------------------------------ | ------------------------------------------ | -------------------------------------- |
| Step-group (top-level item) | Runs sequentially relative to other groups | First group contains `first-moo` |
| Steps in a group (inner items) | Run in parallel with each other | `parallel-moo-a` and `parallel-moo-b` |
| Entry point | Template name used to start the workflow | `entrypoint: triple-moo` |
| Reusable template | Called by steps with parameters | `cow-says` accepts `message` parameter |
Best practices
* Use Steps templates when you need explicit ordering and occasional parallelism between tasks.
* Keep reusable work in separate templates and pass parameters for customization.
* Use clear step names to make the execution tree easy to read when inspecting runs with `argo get`.
Links and references
* [Argo Workflows Documentation](https://argoproj.github.io/argo-workflows/)
* [Argo Workflows: Steps Templates](https://argoproj.github.io/argo-workflows/workflow-concepts/#steps)
* [rancher/cowsay on Docker Hub](https://hub.docker.com/r/rancher/cowsay)