Beginning of argo-worflows testing.

Workflows/.gitignore

+couler.git
+venv

Workflows/argo-workflows-Testing.md

+# First hands-on contact with Argo-Workflows
+
+## Argo-Workflows server quick start
+
+Refer to the [install notes](https://argoproj.github.io/argo-workflows/quick-start/#install-argo-workflows) that boils down to
+
+```bash
+minikube --memory 8192 --cpus 4 start
+kubectl create ns argo
+kubectl apply -n argo -f https://raw.githubusercontent.com/argoproj/argo-workflows/stable/manifests/quick-start-postgres.yaml
+kubectl -n argo port-forward deployment/argo-server 2746:2746
+```
+
+and open `https://localhost:2746` with your web-browser.
+
+## Running argo from CLI (yaml workflow)
+
+For v3.0.8 refer to this [argo CLI install reference](https://github.com/argoproj/argo-workflows/releases/tag/v3.0.8) (look for the "Argo CLI" chapter) that for Mac states
+
+```bash
+curl -sLO https://github.com/argoproj/argo/releases/download/v3.0.8/argo-darwin-amd64.gz
+gunzip argo-darwin-amd64.gz
+chmod +x argo-darwin-amd64
+mv ./argo-darwin-amd64 /usr/local/bin/argo
+argo version
+```
+
+```bash
+argo submit -n argo --watch https://raw.githubusercontent.com/argoproj/argo-workflows/master/examples/hello-world.yaml
+```
+
+## Running argo from Python-SDK (Couler) examples
+
+Note: although they seem to exist three Python SDK's for argo, namely
+[argo-client-python](https://github.com/argoproj-labs/argo-client-python/),
+[argo-python-dsl](https://github.com/argoproj-labs/argo-python-dsl) and
+[couler](https://couler-proj.github.io/couler/), only the latter seems to be
+still under-development.
+  
+[Couler](https://couler-proj.github.io/couler/), the Argo Workflows Python-SDK,
+presents itself as being platform-agnostic enough to provide "a unified
+interface for constructing and managing workflows on different workflow
+engines, such as Argo Workflows, Tekton Pipelines, and Apache Airflow".
+
+[Couler documentation](https://couler-proj.github.io/couler/) provides
+[some examples](https://couler-proj.github.io/couler/examples/#dag) that
+can be run from CLI with Python:
+
+```bash
+$ virtualenv -p python3 venv
+$ . venv/bin/activate
+(venv)$ pip install git+https://github.com/couler-proj/couler
+```
+
+```bash
+$ git clone https://github.com/couler-proj/couler couler.git
+```
+
+By default the `couler.git/examples/hello_world.py` runs smoothly but within
+the "default" (k8s) namespace that doesn't seem obvious to find under the Web
+UI:
+
+```bash
+(venv)$ python couler.git/examples/hello_world.py
+```
+
+This is why we copied it (`cp couler.git/examples/hello_world.py .`) and
+modified to run in the "argo" namespace:
+
+```bash
+(venv)$ python hello_world.py    # In CWD not in couler.git 
+```
+
+and observe it running under the UI (in the "argo" namespace).

Workflows/dag.py

+# Copied from https://github.com/couler-proj/couler/examples/hello_world.py
+# just to try changing the namespace (from default to argo)
+import couler.argo as couler
+from couler.argo_submitter import ArgoSubmitter
+
+
+def job_a(message):
+    couler.run_container(
+        image="docker/whalesay:latest",
+        command=["cowsay"],
+        args=[message],
+        step_name="A",
+    )
+
+
+def job_b(message):
+    couler.run_container(
+        image="docker/whalesay:latest",
+        command=["cowsay"],
+        args=[message],
+        step_name="B",
+    )
+
+
+def job_c(message):
+    couler.run_container(
+        image="docker/whalesay:latest",
+        command=["cowsay"],
+        args=[message],
+        step_name="C",
+    )
+
+
+def job_d(message):
+    couler.run_container(
+        image="docker/whalesay:latest",
+        command=["cowsay"],
+        args=[message],
+        step_name="D",
+    )
+
+
+#     A
+#    / \
+#   B   C
+#  /
+# D
+def linear():
+    couler.set_dependencies(lambda: job_a(message="A"), dependencies=None)
+    couler.set_dependencies(lambda: job_b(message="B"), dependencies=["A"])
+    couler.set_dependencies(lambda: job_c(message="C"), dependencies=["A"])
+    couler.set_dependencies(lambda: job_d(message="D"), dependencies=["B"])
+
+
+#   A
+#  / \
+# B   C
+#  \ /
+#   D
+def diamond():
+    couler.dag(
+        [
+            [lambda: job_a(message="A")],
+            [lambda: job_a(message="A"), lambda: job_b(message="B")],  # A -> B
+            [lambda: job_a(message="A"), lambda: job_c(message="C")],  # A -> C
+            [lambda: job_b(message="B"), lambda: job_d(message="D")],  # B -> D
+            [lambda: job_c(message="C"), lambda: job_d(message="D")],  # C -> D
+        ]
+    )
+
+
+# linear()
+diamond()
+submitter = ArgoSubmitter(namespace='argo')
+couler.run(submitter=submitter)

Workflows/hello_world.py

+# Copied from https://github.com/couler-proj/couler/examples/hello_world.py
+# just to try changing the namespace (from default to argo)
+import couler.argo as couler
+from couler.argo_submitter import ArgoSubmitter
+
+couler.run_container(
+    image="docker/whalesay", command=["cowsay"], args=["hello world"]
+)
+
+submitter = ArgoSubmitter(namespace='argo')
+result = couler.run(submitter=submitter)