Update plan_summary to support running documentation examples

tools/plan_summary.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 
-# Copyright 2022 Google LLC
+# Copyright 2023 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -16,6 +16,7 @@
 
 import click
 import sys
+import tempfile
 import yaml
 
 from pathlib import Path
@@ -27,17 +28,32 @@ import fixtures
 
 
 @click.command()
+@click.option('--example', default=False, is_flag=True)
 @click.argument('module', type=click.Path(), nargs=1)
 @click.argument('tfvars', type=click.Path(exists=True), nargs=-1)
-def main(module, tfvars):
-  module = BASEDIR / module
-  summary = fixtures.plan_summary(module, Path(), tfvars)
-  print(yaml.dump({'values': summary.values}))
-  print(yaml.dump({'counts': summary.counts}))
-  outputs = {
-      k: v.get('value', '__missing__') for k, v in summary.outputs.items()
-  }
-  print(yaml.dump({'outputs': outputs}))
+def main(example, module, tfvars):
+  try:
+    if example:
+      tmp_dir = tempfile.TemporaryDirectory()
+      tmp_path = Path(tmp_dir.name)
+      common_vars = BASEDIR / 'tests' / 'examples' / 'variables.tf'
+      (tmp_path / 'main.tf').symlink_to(module)
+      (tmp_path / 'variables.tf').symlink_to(common_vars)
+      (tmp_path / 'fabric').symlink_to(BASEDIR)
+      module = tmp_path
+    else:
+      module = BASEDIR / module
+
+    summary = fixtures.plan_summary(module, Path(), tfvars)
+    print(yaml.dump({'values': summary.values}))
+    print(yaml.dump({'counts': summary.counts}))
+    outputs = {
+        k: v.get('value', '__missing__') for k, v in summary.outputs.items()
+    }
+    print(yaml.dump({'outputs': outputs}))
+  finally:
+    if example:
+      tmp_dir.cleanup()
 
 
 if __name__ == '__main__':