refactor: Rename requirements.in to requirements.txt. (#2619)

Rename requirements.in to requirements.txt. It is a more standard way to manage Python dependencies, it can be recognized automatically by some IDEs.

Add environment setup section to README for running hermetic build scripts.

.cloudbuild/library_generation/library_generation.Dockerfile

@@ -26,7 +26,7 @@ RUN rm $(which python3)
 RUN ln -s $(which python3.11) /usr/local/bin/python
 RUN ln -s $(which python3.11) /usr/local/bin/python3
 RUN python -m pip install --upgrade pip
-RUN cd /src && python -m pip install -r requirements.in
+RUN cd /src && python -m pip install -r requirements.txt
 RUN cd /src && python -m pip install .
 
 # set dummy git credentials for empty commit used in postprocessing

.github/workflows/verify_library_generation.yaml

@@ -10,17 +10,9 @@ on:
 name: verify_library_generation
 jobs:
   integration_tests:
-    strategy:
-      matrix:
-        java: [ 11 ]
     runs-on: ubuntu-22.04
     steps:
     - uses: actions/checkout@v4
-    - uses: actions/setup-java@v4
-      with:
-        java-version: ${{ matrix.java }}
-        distribution: temurin
-        cache: maven
     - uses: actions/setup-python@v5
       with:
         python-version: 3.11
@@ -41,7 +33,7 @@ jobs:
       run: |
         set -ex
         pushd library_generation
-        pip install -r requirements.in
+        pip install -r requirements.txt
         pip install .
         popd
     - name: Run integration tests
@@ -71,7 +63,7 @@ jobs:
       run: |
         set -ex
         pushd library_generation
-        pip install -r requirements.in
+        pip install -r requirements.txt
         popd
     - name: install synthtool
       shell: bash
@@ -115,7 +107,7 @@ jobs:
       run: |
         set -ex
         pushd library_generation
-        pip install -r requirements.in
+        pip install -r requirements.txt
         popd
     - name: Lint
       shell: bash

library_generation/README.md

@@ -10,6 +10,8 @@ google-cloud-java) from a configuration file.
 - Java runtime environment (8 or above)
 - Apache Maven (used in formatting source code)
 - Python (3.11.6 or above)
+- Docker 
+- Git
 
 ## Prerequisite
 
@@ -188,22 +190,26 @@ libraries:
       - proto_path: google/cloud/asset/v1p7beta1
 ```
 
+# Local Environment Setup before running `entry_point.py`
+
+1. Assuming Python 3 is installed, follow official guide from [Python.org](https://packaging.python.org/en/latest/guides/installing-using-pip-and-virtual-environments/#create-and-use-virtual-environments) to create a virtual environment. The virtual environment can be installed to any folder, usually it is recommended to be installed under the root folder of the project(`sdk-platform-java` in this case).
+2. Assuming the virtual environment is installed under `sdk-platform-java`. Run the following command under the root folder of `sdk-platform-java` to install the dependencies of `library_generation`
+```bash
+python -m pip install -r library_generation/requirements.txt
+```
+3. Run the following command to install `library_generation` as a module, which allows the `library_generation` module to be imported from anywhere
+```bash
+python -m pip install library_generation/
+```
+
 ## An example to generate a repository using `entry_point.py`
 
 ```bash
-# install python module (allows the `library_generation` module to be imported from anywhere)
-python -m pip install -r library_generation/requirements.in
-# install library_generation module
-python -m pip install library_generation
-# generate the repository
-python -m library_generation/entry_point.py generate \
+python library_generation/entry_point.py generate \
 --baseline-generation-config=/path/to/baseline_config_file \
 --current-generation-config=/path/to/current_config_file \
---repository-path=/path/to/repository
+--repository-path=path/to/repository
 ```
-
-## An example of generated repository using `entry_point.py`
-
 If you run `entry_point.py` with the example [configuration](#an-example-of-generation-configuration)
 shown above, the repository structure is:
 ```