refactor: reduce linux indentation with nicer breakup

cibuildwheel/linux.py

@@ -87,43 +87,15 @@ def get_linux_platforms(
         yield platform_configs, platform_tag, docker_image
 
 
-def build(options: BuildOptions) -> None:
+def build_on_docker(
-    try:
+    options: BuildOptions,
-        # check docker is installed
+    platform_configs: List[PythonConfiguration],
-        subprocess.run(["docker", "--version"], check=True, stdout=subprocess.DEVNULL)
+    docker: DockerContainer,
-    except Exception:
+    container_project_path: PurePath,
-        print(
+    container_package_dir: PurePath,
-            "cibuildwheel: Docker not found. Docker is required to run Linux builds. "
+) -> None:
-            "If you're building on Travis CI, add `services: [docker]` to your .travis.yml."
-            "If you're building on Circle CI in Linux, add a `setup_remote_docker` step to your .circleci/config.yml",
-            file=sys.stderr,
-        )
-        sys.exit(2)
-
-    assert options.manylinux_images is not None
-    assert options.musllinux_images is not None
-    python_configurations = get_python_configurations(options.build_selector, options.architectures)
-
-    cwd = Path.cwd()
-    abs_package_dir = options.package_dir.resolve()
-    if cwd != abs_package_dir and cwd not in abs_package_dir.parents:
-        raise Exception("package_dir must be inside the working directory")
-
-    container_project_path = PurePath("/project")
-    container_package_dir = container_project_path / abs_package_dir.relative_to(cwd)
     container_output_dir = PurePath("/output")
 
-    for platform_configs, platform_tag, docker_image in get_linux_platforms(
-        options, python_configurations
-    ):
-        try:
-            log.step(f"Starting Docker image {docker_image}...")
-            with DockerContainer(
-                docker_image,
-                simulate_32_bit=platform_tag.endswith("i686"),
-                cwd=container_project_path,
-            ) as docker:
-
     log.step("Copying project into Docker...")
     docker.copy_into(Path.cwd(), container_project_path)
 
@@ -133,9 +105,7 @@ def build(options: BuildOptions) -> None:
         env = docker.get_environment()
         env["PATH"] = f'/opt/python/cp38-cp38/bin:{env["PATH"]}'
         env["PIP_DISABLE_PIP_VERSION_CHECK"] = "1"
-                    env = options.environment.as_dictionary(
+        env = options.environment.as_dictionary(env, executor=docker.environment_executor)
-                        env, executor=docker.environment_executor
-                    )
 
         before_all_prepared = prepare_command(
             options.before_all,
@@ -150,9 +120,7 @@ def build(options: BuildOptions) -> None:
         dependency_constraint_flags: List[PathOrStr] = []
 
         if options.dependency_constraints:
-                        constraints_file = options.dependency_constraints.get_for_python_version(
+            constraints_file = options.dependency_constraints.get_for_python_version(config.version)
-                            config.version
-                        )
             container_constraints_file = PurePath("/constraints.txt")
 
             docker.copy_into(constraints_file, container_constraints_file)
@@ -166,14 +134,10 @@ def build(options: BuildOptions) -> None:
         python_bin = config.path / "bin"
         env["PATH"] = f'{python_bin}:{env["PATH"]}'
 
-                    env = options.environment.as_dictionary(
+        env = options.environment.as_dictionary(env, executor=docker.environment_executor)
-                        env, executor=docker.environment_executor
-                    )
 
         # check config python is still on PATH
-                    which_python = docker.call(
+        which_python = docker.call(["which", "python"], env=env, capture_output=True).strip()
-                        ["which", "python"], env=env, capture_output=True
-                    ).strip()
         if PurePath(which_python) != python_bin / "python":
             print(
                 "cibuildwheel: python available on PATH doesn't match our installed instance. If you have modified PATH, ensure that you don't overwrite cibuildwheel's entry or insert python above it.",
@@ -263,17 +227,10 @@ def build(options: BuildOptions) -> None:
 
             # set up a virtual environment to install and test from, to make sure
             # there are no dependencies that were pulled in at build time.
-                        docker.call(
+            docker.call(["pip", "install", "virtualenv", *dependency_constraint_flags], env=env)
-                            ["pip", "install", "virtualenv", *dependency_constraint_flags], env=env
+            venv_dir = PurePath(docker.call(["mktemp", "-d"], capture_output=True).strip()) / "venv"
-                        )
-                        venv_dir = (
-                            PurePath(docker.call(["mktemp", "-d"], capture_output=True).strip())
-                            / "venv"
-                        )
 
-                        docker.call(
+            docker.call(["python", "-m", "virtualenv", "--no-download", venv_dir], env=env)
-                            ["python", "-m", "virtualenv", "--no-download", venv_dir], env=env
-                        )
 
             virtualenv_env = env.copy()
             virtualenv_env["PATH"] = f"{venv_dir / 'bin'}:{virtualenv_env['PATH']}"
@@ -300,9 +257,7 @@ def build(options: BuildOptions) -> None:
 
             # Install any requirements to run the tests
             if options.test_requires:
-                            docker.call(
+                docker.call(["pip", "install", *options.test_requires], env=virtualenv_env)
-                                ["pip", "install", *options.test_requires], env=virtualenv_env
-                            )
 
             # Run the tests from a different directory
             test_command_prepared = prepare_command(
@@ -310,9 +265,7 @@ def build(options: BuildOptions) -> None:
                 project=container_project_path,
                 package=container_package_dir,
             )
-                        docker.call(
+            docker.call(["sh", "-c", test_command_prepared], cwd="/root", env=virtualenv_env)
-                            ["sh", "-c", test_command_prepared], cwd="/root", env=virtualenv_env
-                        )
 
             # clean up test environment
             docker.call(["rm", "-rf", venv_dir])
@@ -327,6 +280,47 @@ def build(options: BuildOptions) -> None:
     # copy the output back into the host
     docker.copy_out(container_output_dir, options.output_dir)
     log.step_end()
+
+
+def build(options: BuildOptions) -> None:
+    try:
+        # check docker is installed
+        subprocess.run(["docker", "--version"], check=True, stdout=subprocess.DEVNULL)
+    except Exception:
+        print(
+            "cibuildwheel: Docker not found. Docker is required to run Linux builds. "
+            "If you're building on Travis CI, add `services: [docker]` to your .travis.yml."
+            "If you're building on Circle CI in Linux, add a `setup_remote_docker` step to your .circleci/config.yml",
+            file=sys.stderr,
+        )
+        sys.exit(2)
+
+    assert options.manylinux_images is not None
+    assert options.musllinux_images is not None
+    python_configurations = get_python_configurations(options.build_selector, options.architectures)
+
+    cwd = Path.cwd()
+    abs_package_dir = options.package_dir.resolve()
+    if cwd != abs_package_dir and cwd not in abs_package_dir.parents:
+        raise Exception("package_dir must be inside the working directory")
+
+    container_project_path = PurePath("/project")
+    container_package_dir = container_project_path / abs_package_dir.relative_to(cwd)
+
+    for platform_configs, platform_tag, docker_image in get_linux_platforms(
+        options, python_configurations
+    ):
+        try:
+            log.step(f"Starting Docker image {docker_image}...")
+            with DockerContainer(
+                docker_image,
+                simulate_32_bit=platform_tag.endswith("i686"),
+                cwd=container_project_path,
+            ) as docker:
+                build_on_docker(
+                    options, platform_configs, docker, container_project_path, container_package_dir
+                )
+
         except subprocess.CalledProcessError as error:
             log.step_end_with_error(
                 f"Command {error.cmd} failed with code {error.returncode}. {error.stdout}"