GHA: Use same commands the CLI does to create venv (#5206)

Use the same commands the CLI does to create venv for Python projects, and add a test.

dist/actions/entrypoint.sh

@@ -124,9 +124,8 @@ if [ -e requirements.txt ]; then
         pip3 install -r requirements.txt
     else
         python3 -m venv $PULUMI_VENV
-        source $PULUMI_VENV/bin/activate
-        pip3 install -r requirements.txt
-        deactivate
+        $PULUMI_VENV/bin/python -m pip install --upgrade pip setuptools wheel
+        $PULUMI_VENV/bin/python -m pip install -r requirements.txt
     fi
 fi
 

tests/containers/containers_test.go

@@ -112,6 +112,10 @@ func TestPulumiActionsImage(t *testing.T) {
 	t.Run("python", func(t *testing.T) {
 		testRuntimeWorksInContainer(t, "python", pulumiContainerToTest)
 	})
+
+	t.Run("python_venv", func(t *testing.T) {
+		testRuntimeWorksInContainer(t, "python_venv", pulumiContainerToTest)
+	})
 }
 
 // testRuntimeWorksInContainer runs a test that attempts to run a Pulumi program in the given

tests/containers/python_venv/.gitignore

@@ -0,0 +1,2 @@
+*.pyc
+venv/

tests/containers/python_venv/Pulumi.yaml

@@ -0,0 +1,6 @@
+name: trivial-python
+description: A trivial Pulumi program for Python that has virtualenv set
+runtime:
+  name: python
+  options:
+    virtualenv: venv

tests/containers/python_venv/__main__.py

@@ -0,0 +1,4 @@
+import pulumi
+
+config = pulumi.Config()
+print("Hello from %s" % (config.require("runtime")))

tests/containers/python_venv/requirements.txt

@@ -0,0 +1 @@
+pulumi>=1.0.0