feat(cli): python project template (#36)

The command cdk8s init python-app will create a new python cdk8s project.

NOTE: this is intentionally not documented yet since we still don’t support cdk8s gen for python, so basically this only allows defining resources by directly instantiating ApiObjects. But this is still functional.

packages/cdk8s-cli/templates/python-app/.hooks.sscaff.js

@@ -0,0 +1,23 @@
+const { execSync } = require('child_process');
+const { chmodSync } = require('fs');
+
+exports.pre = () => {
+  try {
+    execSync('which pipenv')
+  } catch {
+    console.error(`Unable to find "pipenv". Please install https://pipenv.kennethreitz.org/`)
+    process.exit(1);
+  }
+};
+
+exports.post = () => {
+  execSync('pipenv install', { stdio: 'inherit' });
+
+  console.log();
+  console.log("==================================================================================");
+  console.log(" Your cdk8s Python project was created successfully.");
+  console.log();
+  console.log(" Useful commands:");
+  console.log(" - pipenv install: creates a virtual environment and installs deps");
+  console.log(" - pipenv run python main.py: synthesizes a k8s manifest in 'dist/' (ready for 'kubectl apply -f')");
+};

packages/cdk8s-cli/templates/python-app/Pipfile

@@ -0,0 +1,14 @@
+[[source]]
+name = "pypi"
+url = "https://pypi.org/simple"
+verify_ssl = true
+
+[dev-packages]
+pylint = "*"
+
+[packages]
+aws-cdk-core = "*"
+cdk8s = "*"
+
+[requires]
+python_version = "3.7"

packages/cdk8s-cli/templates/python-app/main.py

@@ -0,0 +1,13 @@
+from aws_cdk.core import Construct
+from cdk8s import App, Chart
+
+class MyChart(Chart):
+  def __init__(self, scope: Construct, ns: str, **kwargs):
+    super().__init__(scope, ns, **kwargs)
+
+    # define resources here
+
+app = App()
+MyChart(app, "{{ $base }}")
+
+app.synth()