Add on-cluster workflow test to CI (#887)

**Pull Request Checklist**
- [x] Fixes #652
- [x] Tests added
- [x] Documentation/examples added
- [x] [Good commit messages](https://cbea.ms/git-commit/) and/or PR
title

**Description of PR**
Introduce local Argo cluster workflow tests to CI, and `make` targets to
set up a local cluster for testing (this worked very well on GitHub
codespaces, where I could even get a web UI to the cluster).

Added a single test to confirm the workflow runs via `create` and
reaches the `succeeded` `status.phase`. We can think about creating a
more flexible/extensible framework for adding `on_cluster` tests -
* I'd like to use a subset of our examples
* But we want to assert on more than the `status.phase`, e.g. output
values, running order, skipped nodes etc, which would require bespoke
tests for each
* It would also be good to have a wrapper for fetching these values,
e.g. getting a node requires iterating through the `status.nodes`
dictionary, which is keyed by hashes, so you have to check `displayName`
from the values.

---------

Signed-off-by: Elliot Gunton <egunton@bloomberg.net>

.github/workflows/cicd.yaml

@@ -91,6 +91,42 @@ jobs:
         with:
           file: ./coverage.xml
 
+  workflow-tests:
+    name: run workflow tests
+    timeout-minutes: 10
+    strategy:
+      fail-fast: false
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: checkout
+        uses: actions/checkout@v4
+
+      - name: Install poetry
+        run: pipx install poetry
+
+      - name: setup python 3.8
+        uses: actions/setup-python@v5
+        with:
+          python-version: 3.8
+          cache: "poetry"
+
+      - name: Install dependencies
+        run: poetry install
+
+      - name: setup k3d cluster
+        run: make install-k3d
+
+      - name: setup and run argo
+        run: make run-argo
+
+      - name: run workflow tests
+        run: make test-on-cluster
+
+      - name: stop argo cluster
+        run: make stop-argo
+
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref || github.run_id }}
   cancel-in-progress: true

Makefile

@@ -44,7 +44,7 @@ lint:  ## Run a `lint` process on Hera and report problems
 
 .PHONY: test
 test:  ## Run tests for Hera
-	@poetry run python -m pytest --cov-report=term-missing
+	@poetry run python -m pytest --cov-report=term-missing -m "not on_cluster"
 
 .PHONY: workflows-models
 workflows-models: ## Generate the Workflows models portion of Argo Workflows
@@ -126,3 +126,42 @@ regenerate-test-data: install-3.8
 	find examples -name "*.yaml" -type f -delete
 	HERA_REGENERATE=1 make test examples
 	@poetry run python -m pytest -k test_for_missing_examples --runxfail
+
+.PHONY: install-k3d
+install-k3d: ## Install k3d client
+	curl -s https://raw.githubusercontent.com/k3d-io/k3d/main/install.sh | bash
+
+.PHONY: install-argo
+install-argo:  ## Install argo client
+	# Download the binary
+	curl -sLO https://github.com/argoproj/argo-workflows/releases/download/v$(ARGO_WORKFLOWS_VERSION)/argo-linux-amd64.gz
+
+	# Unzip
+	gunzip argo-linux-amd64.gz
+
+	# Make binary executable
+	chmod +x argo-linux-amd64
+
+	# Move binary to path
+	sudo mv ./argo-linux-amd64 /usr/local/bin/argo
+
+	# Test installation
+	argo version
+
+.PHONY: run-argo
+run-argo: ## Start the argo server
+	k3d cluster list | grep test-cluster || k3d cluster create test-cluster
+	k3d kubeconfig merge test-cluster --kubeconfig-switch-context
+	kubectl get namespace argo || kubectl create namespace argo
+	kubectl apply -n argo -f https://github.com/argoproj/argo-workflows/releases/download/v$(ARGO_WORKFLOWS_VERSION)/install.yaml
+	kubectl patch deployment argo-server --namespace argo --type='json' -p='[{"op": "replace", "path": "/spec/template/spec/containers/0/args", "value": ["server", "--auth-mode=server"]}]'
+	kubectl rollout status -n argo deployment/argo-server --timeout=120s --watch=true
+
+.PHONY: stop-argo
+stop-argo:  ## Stop the argo server
+	k3d cluster stop test-cluster
+
+.PHONY: test-on-cluster
+test-on-cluster: ## Run workflow tests (requires local argo cluster)
+	@(kubectl -n argo port-forward deployment/argo-server 2746:2746 &)
+	@poetry run python -m pytest tests/test_submission.py -m on_cluster

examples/workflows-examples.md

@@ -1 +1 @@
-docs/examples/workflows-examples.md
+../docs/examples/workflows-examples.md

pyproject.toml

@@ -60,6 +60,9 @@ filterwarnings = [
     # Hide the hera.host_config deprecations
     'ignore:.*is deprecated in favor of `global_config.GlobalConfig',
 ]
+markers = [
+    "on_cluster: tests that run on an Argo cluster",
+]
 
 # Convert the following to config
 [tool.mypy]

tests/test_submission.py

@@ -0,0 +1,30 @@
+import pytest
+
+from hera.workflows import Steps, Workflow, WorkflowsService, script
+
+
+@script()
+def echo(message: str):
+    print(message)
+
+
+def get_workflow() -> Workflow:
+    with Workflow(
+        generate_name="hello-world-",
+        entrypoint="steps",
+        namespace="argo",
+        workflows_service=WorkflowsService(
+            host="https://localhost:2746",
+            namespace="argo",
+            verify_ssl=False,
+        ),
+    ) as w:
+        with Steps(name="steps"):
+            echo(arguments={"message": "Hello world!"})
+    return w
+
+
+@pytest.mark.on_cluster
+def test_create_hello_world():
+    model_workflow = get_workflow().create(wait=True)
+    assert model_workflow.status and model_workflow.status.phase == "Succeeded"