fix(lambda-python): bundling artifacts are written to the entry path (a…

…ws#21967)

When performing function bundling sometimes the bundling steps will write files. Currently all these commands are run from the `entry` which is the actually source code location. This leads to contaminating the source code with bundling artifacts.

This PR re-orders the bundling steps to first move the `entry` to the `outputDir` and then perform the bundling steps there.

I've also updated all of the integration tests to use the new integration test framework and assertions.

fixes aws#19231


----

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### Adding new Unconventional Dependencies:

* [ ] This PR adds new unconventional dependencies following the process described [here](https://github.com/aws/aws-cdk/blob/main/CONTRIBUTING.md/#adding-new-unconventional-dependencies)

### New Features

* [ ] Have you added the new feature to an [integration test](https://github.com/aws/aws-cdk/blob/main/INTEGRATION_TESTS.md)?
	* [ ] Did you use `yarn integ` to deploy the infrastructure and generate the snapshot (i.e. `yarn integ` without `--dry-run`)?

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*

packages/@aws-cdk/aws-lambda-python/lib/bundling.ts

@@ -91,11 +91,12 @@ export class Bundling implements CdkBundlingOptions {
   private createBundlingCommand(options: BundlingCommandOptions): string[] {
     const packaging = Packaging.fromEntry(options.entry);
     let bundlingCommands: string[] = [];
+    bundlingCommands.push(`cp -rTL ${options.inputDir}/ ${options.outputDir}`);
+    bundlingCommands.push(`cd ${options.outputDir}`);
     bundlingCommands.push(packaging.exportCommand ?? '');
     if (packaging.dependenciesFile) {
       bundlingCommands.push(`python -m pip install -r ${DependenciesFile.PIP} -t ${options.outputDir}`);
     }
-    bundlingCommands.push(`cp -rT ${options.inputDir}/ ${options.outputDir}`);
     return bundlingCommands;
   }
 }

packages/@aws-cdk/aws-lambda-python/test/bundling.test.ts

@@ -37,7 +37,7 @@ test('Bundling a function without dependencies', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'cp -rT /asset-input/ /asset-output',
+        'cp -rTL /asset-input/ /asset-output && cd /asset-output',
       ],
     }),
   }));
@@ -66,7 +66,7 @@ test('Bundling a function with requirements.txt', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'python -m pip install -r requirements.txt -t /asset-output && cp -rT /asset-input/ /asset-output',
+        'cp -rTL /asset-input/ /asset-output && cd /asset-output && python -m pip install -r requirements.txt -t /asset-output',
       ],
     }),
   }));
@@ -89,7 +89,7 @@ test('Bundling Python 2.7 with requirements.txt installed', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'python -m pip install -r requirements.txt -t /asset-output && cp -rT /asset-input/ /asset-output',
+        'cp -rTL /asset-input/ /asset-output && cd /asset-output && python -m pip install -r requirements.txt -t /asset-output',
       ],
     }),
   }));
@@ -109,7 +109,7 @@ test('Bundling a layer with dependencies', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'python -m pip install -r requirements.txt -t /asset-output/python && cp -rT /asset-input/ /asset-output/python',
+        'cp -rTL /asset-input/ /asset-output/python && cd /asset-output/python && python -m pip install -r requirements.txt -t /asset-output/python',
       ],
     }),
   }));
@@ -129,7 +129,7 @@ test('Bundling a python code layer', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'cp -rT /asset-input/ /asset-output/python',
+        'cp -rTL /asset-input/ /asset-output/python && cd /asset-output/python',
       ],
     }),
   }));
@@ -149,7 +149,7 @@ test('Bundling a function with pipenv dependencies', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'PIPENV_VENV_IN_PROJECT=1 pipenv lock -r > requirements.txt && rm -rf .venv && python -m pip install -r requirements.txt -t /asset-output/python && cp -rT /asset-input/ /asset-output/python',
+        'cp -rTL /asset-input/ /asset-output/python && cd /asset-output/python && PIPENV_VENV_IN_PROJECT=1 pipenv lock -r > requirements.txt && rm -rf .venv && python -m pip install -r requirements.txt -t /asset-output/python',
       ],
     }),
   }));
@@ -176,7 +176,7 @@ test('Bundling a function with poetry dependencies', () => {
     bundling: expect.objectContaining({
       command: [
         'bash', '-c',
-        'poetry export --with-credentials --format requirements.txt --output requirements.txt && python -m pip install -r requirements.txt -t /asset-output/python && cp -rT /asset-input/ /asset-output/python',
+        'cp -rTL /asset-input/ /asset-output/python && cd /asset-output/python && poetry export --with-credentials --format requirements.txt --output requirements.txt && python -m pip install -r requirements.txt -t /asset-output/python',
       ],
     }),
   }));
@@ -206,7 +206,7 @@ test('Bundling a function with custom bundling image', () => {
       image,
       command: [
         'bash', '-c',
-        'python -m pip install -r requirements.txt -t /asset-output/python && cp -rT /asset-input/ /asset-output/python',
+        'cp -rTL /asset-input/ /asset-output/python && cd /asset-output/python && python -m pip install -r requirements.txt -t /asset-output/python',
       ],
     }),
   }));