feat: Adds disable_host_mount suboption to container-engine

bin/generate_schema.py

@@ -61,9 +61,9 @@
     oneOf:
       - enum: [docker, podman]
       - type: string
-        pattern: '^docker; ?create_args:'
+        pattern: '^docker; ?(create_args|disable_host_mount):'
       - type: string
-        pattern: '^podman; ?create_args:'
+        pattern: '^podman; ?(create_args|disable_host_mount):'
       - type: object
         additionalProperties: false
         required: [name]
@@ -74,6 +74,8 @@
             type: array
             items:
               type: string
+          disable-host-mount:
+            type: boolean
   dependency-versions:
     default: pinned
     description: Specify how cibuildwheel controls the versions of the tools it uses

cibuildwheel/oci_container.py

@@ -32,27 +32,43 @@
 class OCIContainerEngineConfig:
     name: ContainerEngineName
     create_args: Sequence[str] = ()
+    disable_host_mount: bool = False
 
     @staticmethod
     def from_config_string(config_string: str) -> OCIContainerEngineConfig:
         config_dict = parse_key_value_string(
-            config_string, ["name"], ["create_args", "create-args"]
+            config_string,
+            ["name"],
+            ["create_args", "create-args", "disable_host_mount", "disable-host-mount"],
         )
         name = " ".join(config_dict["name"])
         if name not in {"docker", "podman"}:
             msg = f"unknown container engine {name}"
             raise ValueError(msg)
 
         name = typing.cast(ContainerEngineName, name)
-        # some flexibility in the option name to cope with TOML conventions
+        # some flexibility in the option names to cope with TOML conventions
         create_args = config_dict.get("create_args") or config_dict.get("create-args") or []
-        return OCIContainerEngineConfig(name=name, create_args=create_args)
+        disable_host_mount_options = (
+            config_dict.get("disable_host_mount") or config_dict.get("disable-host-mount") or []
+        )
+        disable_host_mount = (
+            strtobool(disable_host_mount_options[-1]) if disable_host_mount_options else False
+        )
+
+        return OCIContainerEngineConfig(
+            name=name, create_args=create_args, disable_host_mount=disable_host_mount
+        )
 
     def options_summary(self) -> str | dict[str, str]:
         if not self.create_args:
             return self.name
         else:
-            return {"name": self.name, "create_args": repr(self.create_args)}
+            return {
+                "name": self.name,
+                "create_args": repr(self.create_args),
+                "disable_host_mount": str(self.disable_host_mount),
+            }
 
 
 DEFAULT_ENGINE = OCIContainerEngineConfig("docker")
@@ -136,7 +152,7 @@ def __enter__(self) -> OCIContainer:
                 "--env=SOURCE_DATE_EPOCH",
                 f"--name={self.name}",
                 "--interactive",
-                "--volume=/:/host",  # ignored on CircleCI
+                *(["--volume=/:/host"] if not self.engine.disable_host_mount else []),
                 *network_args,
                 *self.engine.create_args,
                 self.image,

cibuildwheel/options.py

@@ -378,6 +378,9 @@ def _inner_fmt(k: str, v: Any, table: TableFmt) -> Iterator[str]:
         for inner_v in v:
             qv = quote_function(inner_v)
             yield table["item"].format(k=k, v=qv)
+    elif isinstance(v, bool):
+        qv = quote_function(str(v))
+        yield table["item"].format(k=k, v=qv)
     else:
         qv = quote_function(v)
         yield table["item"].format(k=k, v=qv)

cibuildwheel/resources/cibuildwheel.schema.json

@@ -172,11 +172,11 @@
         },
         {
           "type": "string",
-          "pattern": "^docker; ?create_args:"
+          "pattern": "^docker; ?(create_args|disable_host_mount):"
         },
         {
           "type": "string",
-          "pattern": "^podman; ?create_args:"
+          "pattern": "^podman; ?(create_args|disable_host_mount):"
         },
         {
           "type": "object",
@@ -196,6 +196,9 @@
               "items": {
                 "type": "string"
               }
+            },
+            "disable-host-mount": {
+              "type": "boolean"
             }
           }
         }

cibuildwheel/util.py

@@ -741,7 +741,7 @@ def parse_key_value_string(
     # split by semicolon
     fields = [list(group) for k, group in itertools.groupby(parts, lambda x: x == ";") if not k]
 
-    result: dict[str, list[str]] = defaultdict(list)
+    result: defaultdict[str, list[str]] = defaultdict(list)
     for field_i, field in enumerate(fields):
         # check to see if the option name is specified
         field_name, sep, first_value = field[0].partition(":")
@@ -762,4 +762,4 @@ def parse_key_value_string(
 
         result[field_name] += values
 
-    return result
+    return dict(result)

docs/extra.css

@@ -315,3 +315,9 @@ h1, h2, h3, h4, h5, h6 {
 .wy-menu-vertical li.current a {
 
 }
+
+/* word wrap in table cells */
+.wy-table-responsive table td, .wy-table-responsive table th {
+  white-space: normal;
+  line-height: 1.4;
+}

docs/faq.md

@@ -14,7 +14,7 @@ Linux wheels are built in [`manylinux`/`musllinux` containers](https://github.co
 
     `cibuildwheel` supports this by providing the [`CIBW_ENVIRONMENT`](options.md#environment) and [`CIBW_BEFORE_ALL`](options.md#before-all) options to setup the build environment inside the running container.
 
--   The project directory is copied into the container as `/project`, the output directory for the wheels to be copied out is `/output`. In general, this is handled transparently by `cibuildwheel`. For a more finegrained level of control however, the root of the host file system is mounted as `/host`, allowing for example to access shared files, caches, etc. on the host file system.  Note that `/host` is not available on CircleCI due to their Docker policies.
+-   The project directory is copied into the container as `/project`, the output directory for the wheels to be copied out is `/output`. In general, this is handled transparently by `cibuildwheel`. For a more finegrained level of control however, the root of the host file system is mounted as `/host`, allowing for example to access shared files, caches, etc. on the host file system.  Note that `/host` is not available on CircleCI and GitLab CI due to their Docker policies.
 
 -   Alternative Docker images can be specified with the `CIBW_MANYLINUX_*_IMAGE`/`CIBW_MUSLLINUX_*_IMAGE` options to allow for a custom, preconfigured build environment for the Linux builds. See [options](options.md#linux-image) for more details.
 

docs/options.md

@@ -1069,8 +1069,8 @@ Auditwheel detects the version of the manylinux / musllinux standard in the imag
 
 Options:
 
-- `docker[;create_args: ...]`
-- `podman[;create_args: ...]`
+- `docker[;create_args: ...][;disable_host_mount: true/false]`
+- `podman[;create_args: ...][;disable_host_mount: true/false]`
 
 Default: `docker`
 
@@ -1079,11 +1079,13 @@ Set the container engine to use. Docker is the default, or you can switch to
 running and `docker` available on PATH. To use Podman, it needs to be
 installed and `podman` available on PATH.
 
-Arguments can be supplied to the container engine. Currently, the only option
-that's customisable is 'create_args'. Parameters to create_args are
-space-separated strings, which are passed to the container engine on the
-command line when it's creating the container. If you want to include spaces
-inside a parameter, use shell-style quoting.
+Options can be supplied after the name.
+
+| Option name | Description
+|---|---
+| `create_args` | Space-separated strings, which are passed to the container engine on the command line when it's creating the container. If you want to include spaces inside a parameter, use shell-style quoting.
+| `disable_host_mount` | By default, cibuildwheel will mount the root of the host filesystem as a volume at `/host` in the container. To disable the host mount, pass `true` to this option.
+
 
 !!! tip
 
@@ -1104,6 +1106,9 @@ inside a parameter, use shell-style quoting.
 
     # pass command line options to 'docker create'
     CIBW_CONTAINER_ENGINE: "docker; create_args: --gpus all"
+
+    # disable the /host mount
+    CIBW_CONTAINER_ENGINE: "docker; disable_host_mount: true"
     ```
 
 !!! tab examples "pyproject.toml"
@@ -1115,6 +1120,9 @@ inside a parameter, use shell-style quoting.
 
     # pass command line options to 'docker create'
     container-engine = { name = "docker", create-args = ["--gpus", "all"]}
+
+    # disable the /host mount
+    container-engine = { name = "docker", disable-host-mount = true }
     ```
 
 

unit_test/oci_container_test.py

@@ -14,7 +14,7 @@
 
 from cibuildwheel.environment import EnvironmentAssignmentBash
 from cibuildwheel.oci_container import OCIContainer, OCIContainerEngineConfig
-from cibuildwheel.util import detect_ci_provider
+from cibuildwheel.util import CIProvider, detect_ci_provider
 
 # Test utilities
 
@@ -415,3 +415,29 @@ def test_enforce_32_bit(container_engine, image, shell_args):
             text=True,
         ).stdout
         assert json.loads(container_args) == shell_args
+
+
+@pytest.mark.parametrize(
+    ("config", "should_have_host_mount"),
+    [
+        ("{name}", True),
+        ("{name}; disable_host_mount: false", True),
+        ("{name}; disable_host_mount: true", False),
+    ],
+)
+def test_disable_host_mount(tmp_path: Path, container_engine, config, should_have_host_mount):
+    if detect_ci_provider() in {CIProvider.circle_ci, CIProvider.gitlab}:
+        pytest.skip("Skipping test because docker on this platform does not support host mounts")
+
+    engine = OCIContainerEngineConfig.from_config_string(config.format(name=container_engine.name))
+
+    sentinel_file = tmp_path / "sentinel"
+    sentinel_file.write_text("12345")
+
+    with OCIContainer(engine=engine, image=DEFAULT_IMAGE) as container:
+        host_mount_path = "/host" + str(sentinel_file)
+        if should_have_host_mount:
+            assert container.call(["cat", host_mount_path], capture_output=True) == "12345"
+        else:
+            with pytest.raises(subprocess.CalledProcessError):
+                container.call(["cat", host_mount_path], capture_output=True)

unit_test/options_test.py

@@ -201,41 +201,61 @@ def test_toml_environment_quoting(tmp_path: Path, toml_assignment, result_value)
 
 
 @pytest.mark.parametrize(
-    ("toml_assignment", "result_name", "result_create_args"),
+    ("toml_assignment", "result_name", "result_create_args", "result_disable_host_mount"),
     [
         (
             'container-engine = "podman"',
             "podman",
             [],
+            False,
         ),
         (
             'container-engine = {name = "podman"}',
             "podman",
             [],
+            False,
         ),
         (
             'container-engine = "docker; create_args: --some-option"',
             "docker",
             ["--some-option"],
+            False,
         ),
         (
             'container-engine = {name = "docker", create-args = ["--some-option"]}',
             "docker",
             ["--some-option"],
+            False,
         ),
         (
             'container-engine = {name = "docker", create-args = ["--some-option", "value that contains spaces"]}',
             "docker",
             ["--some-option", "value that contains spaces"],
+            False,
         ),
         (
             'container-engine = {name = "docker", create-args = ["--some-option", "value;that;contains;semicolons"]}',
             "docker",
             ["--some-option", "value;that;contains;semicolons"],
+            False,
+        ),
+        (
+            'container-engine = {name = "docker", disable-host-mount = true}',
+            "docker",
+            [],
+            True,
+        ),
+        (
+            'container-engine = {name = "docker", disable_host_mount = true}',
+            "docker",
+            [],
+            True,
         ),
     ],
 )
-def test_container_engine_option(tmp_path: Path, toml_assignment, result_name, result_create_args):
+def test_container_engine_option(
+    tmp_path: Path, toml_assignment, result_name, result_create_args, result_disable_host_mount
+):
     args = CommandLineArguments.defaults()
     args.package_dir = tmp_path
 
@@ -253,6 +273,7 @@ def test_container_engine_option(tmp_path: Path, toml_assignment, result_name, r
 
     assert parsed_container_engine.name == result_name
     assert parsed_container_engine.create_args == result_create_args
+    assert parsed_container_engine.disable_host_mount == result_disable_host_mount
 
 
 def test_environment_pass_references():