Rust plugin: rewrite the Rust plugin ...

... using the new plugin system

Signed-off-by: Zixing Liu <zixing.liu@canonical.com>

snapcraft/parts/plugins/__init__.py

@@ -23,12 +23,14 @@
 from .kernel_plugin import KernelPlugin
 from .python_plugin import PythonPlugin
 from .register import register
+from .rust_plugin import RustPlugin
 
 __all__ = [
     "ColconPlugin",
     "CondaPlugin",
     "FlutterPlugin",
     "KernelPlugin",
     "PythonPlugin",
+    "RustPlugin",
     "register",
 ]

snapcraft/parts/plugins/register.py

@@ -23,6 +23,7 @@
 from .flutter_plugin import FlutterPlugin
 from .kernel_plugin import KernelPlugin
 from .python_plugin import PythonPlugin
+from .rust_plugin import RustPlugin
 
 
 def register() -> None:
@@ -32,3 +33,4 @@ def register() -> None:
     craft_parts.plugins.register({"flutter": FlutterPlugin})
     craft_parts.plugins.register({"python": PythonPlugin})
     craft_parts.plugins.register({"kernel": KernelPlugin})
+    craft_parts.plugins.register({"rust": RustPlugin})

snapcraft/parts/plugins/rust_plugin.py

@@ -0,0 +1,185 @@
+# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
+#
+# Copyright (C) 2023 Canonical Ltd
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 3 as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""The Snapcraft Rust plugin."""
+
+import logging
+import subprocess
+from typing import Any, Dict, List, Set, cast
+
+from craft_parts import plugins
+from overrides import overrides
+
+logger = logging.getLogger(__name__)
+
+
+class RustPluginProperties(plugins.PluginProperties, plugins.PluginModel):
+    """The part properties used by the Rust plugin."""
+
+    source: str
+    rust_channel: str = "stable"
+    rust_features: List[str] = []
+    rust_path: List[str] = ["."]
+    rust_use_global_lto: bool = False
+    rust_no_default_features: bool = False
+
+    @classmethod
+    @overrides
+    def unmarshal(cls, data: Dict[str, Any]) -> "RustPluginProperties":
+        """Populate class attributes from the part specification.
+
+        :param data: A dictionary containing part properties.
+
+        :return: The populated plugin properties data object.
+
+        :raise pydantic.ValidationError: If validation fails.
+        """
+        plugin_data = plugins.extract_plugin_properties(
+            data,
+            plugin_name="rust",
+            required=["source"],
+        )
+        return cls(**plugin_data)
+
+
+class RustPlugin(plugins.Plugin):
+    """A Snapcraft plugin for Rust applications.
+
+    This Rust plugin is useful for building Rust based parts.
+
+    Rust uses cargo to drive the build.
+
+    This plugin uses the common plugin keywords as well as those for "sources".
+    For more information check the 'plugins' topic for the former and the
+    'sources' topic for the latter.
+
+    Additionally, this plugin uses the following plugin-specific keywords:
+        - rust-channel
+          (string, default "stable")
+          Used to select which Rust channel or version to use.
+          It can be one of "stable", "beta", "nightly" or a version number.
+          If you don't want this plugin to install Rust toolchain for you,
+          you can put "none" for this option.
+
+        - rust-features
+          (list of strings)
+          Features used to build optional dependencies
+
+        - rust-path
+          (list of strings, default [.])
+          Build specific crates inside the workspace
+
+        - rust-no-default-features
+          (boolean, default False)
+          Whether to disable the default features in this crate.
+          Equivalent to setting `--no-default-features` on the commandline.
+
+        - rust-use-global-lto
+          (boolean, default False)
+          Whether to use global LTO.
+          This option may significantly impact the build performance but
+          reducing the final binary size.
+          This will forcibly enable LTO for all the crates you specified,
+          regardless of whether you have LTO enabled in the Cargo.toml file
+    """
+
+    properties_class = RustPluginProperties
+
+    @overrides
+    def get_build_snaps(self) -> Set[str]:
+        return set()
+
+    @overrides
+    def get_build_packages(self) -> Set[str]:
+        return {"curl", "gcc", "git", "pkg-config", "findutils"}
+
+    def _check_rustup(self) -> bool:
+        try:
+            rustup_version = subprocess.check_output(["rustup", "--version"])
+            return "rustup" in rustup_version.decode("utf-8")
+        except (subprocess.CalledProcessError, FileNotFoundError):
+            return False
+
+    def _get_setup_rustup(self, channel: str) -> List[str]:
+        return [
+            f"""\
+curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | \
+sh -s -- -y --no-modify-path --profile=minimal --default-toolchain {channel}
+"""
+        ]
+
+    @overrides
+    def get_build_environment(self) -> Dict[str, str]:
+        return {
+            "PATH": "${HOME}/.cargo/bin:${PATH}",
+        }
+
+    @overrides
+    def get_build_commands(self) -> List[str]:
+        options = cast(RustPluginProperties, self._options)
+
+        rust_install_cmd: List[str] = []
+        rust_build_cmd: List[str] = []
+        config_cmd: List[str] = []
+
+        if options.rust_channel == "none":
+            rust_install_cmd = []
+        elif not self._check_rustup():
+            logger.info("Rustup not found, installing it")
+            rust_install_cmd = self._get_setup_rustup(options.rust_channel)
+        else:
+            logger.info("Switch rustup channel to %s", options.rust_channel)
+            rust_install_cmd = [f"rustup default {options.rust_channel}"]
+
+        if options.rust_features:
+            features_string = " ".join(options.rust_features)
+            config_cmd.extend(["--features", f"'{features_string}'"])
+
+        if options.rust_use_global_lto:
+            logger.info("Adding overrides for LTO support")
+            config_cmd.extend(
+                [
+                    "--config 'profile.release.lto = true'",
+                    "--config 'profile.release.codegen-units = 1'",
+                ]
+            )
+
+        if options.rust_no_default_features:
+            config_cmd.append("--no-default-features")
+
+        for crate in options.rust_path:
+            logger.info("Generating build commands for %s", crate)
+            config_cmd_string = " ".join(config_cmd)
+            # TODO(liushuyu): the current fallback installation method will also install
+            # compiler plugins into the final Snap, which is likely not what we want.
+            rust_build_cmd_single = f"""\
+if cargo read-manifest --manifest-path "{crate}"/Cargo.toml > /dev/null; then
+    cargo install -f --locked --path "{crate}" --root "${{SNAPCRAFT_PART_INSTALL}}" {config_cmd_string}
+    # remove the installation metadata
+    rm -f "${{SNAPCRAFT_PART_INSTALL}}"/.crates{{.toml,2.json}}
+else
+    # virtual workspace is a bit tricky,
+    # we need to build the whole workspace and then copy the binaries ourselves
+    pushd "{crate}"
+    cargo build --workspace --release {config_cmd_string}
+    # install the final binaries
+    # TODO(liushuyu): this will also install proc macros in the workspace,
+    # which the user may not want to keep in the final installation
+    find ./target/release -maxdepth 1 -executable -exec install -Dvm755 {{}} "${{SNAPCRAFT_PART_INSTALL}}" ';'
+    popd
+fi"""
+            rust_build_cmd.append(rust_build_cmd_single)
+        return rust_install_cmd + rust_build_cmd

snapcraft/plugins/v2/__init__.py

@@ -35,7 +35,6 @@
     PluginV2,
     PythonPlugin,
     QMakePlugin,
-    RustPlugin,
     autotools,
     catkin,
     catkin_tools,
@@ -52,7 +51,6 @@
     npm,
     python,
     qmake,
-    rust,
 )
 
 __all__ = [
@@ -72,7 +70,6 @@
     "npm",
     "python",
     "qmake",
-    "rust",
     "PluginV2",
     "AutotoolsPlugin",
     "CatkinPlugin",
@@ -90,5 +87,4 @@
     "NpmPlugin",
     "PythonPlugin",
     "QMakePlugin",
-    "RustPlugin",
 ]

snapcraft_legacy/plugins/_plugin_finder.py

@@ -41,7 +41,6 @@
         "npm": v2.NpmPlugin,
         "python": v2.PythonPlugin,
         "qmake": v2.QMakePlugin,
-        "rust": v2.RustPlugin,
     }
 else:
     # We cannot import the plugins on anything but linux.

snapcraft_legacy/plugins/v2/__init__.py

@@ -36,4 +36,3 @@
     from .npm import NpmPlugin  # noqa: F401
     from .python import PythonPlugin  # noqa: F401
     from .qmake import QMakePlugin  # noqa: F401
-    from .rust import RustPlugin  # noqa: F401