rust: add support for workspaces

snapcraft/internal/errors.py

@@ -736,3 +736,19 @@ def get_brief(self) -> str:
 
     def get_resolution(self) -> str:
         return "Remove the suspect files from the snap using the `stage` or `prime` keywords."
+
+
+class SnapcraftPluginAssertionError(SnapcraftException):
+    def __init__(self, *, name: str, reason: str, details: str = "") -> None:
+        self._name = name
+        self._reason = reason
+        self._details = details
+
+    def get_brief(self) -> str:
+        return f"Unable to build {self._name!r}: {self._reason}"
+
+    def get_details(self) -> str:
+        return self._details
+
+    def get_resolution(self) -> str:
+        return "Ensure the part's configuration and sources are correct."

snapcraft/plugins/rust.py

@@ -45,14 +45,15 @@
 import collections
 import logging
 import os
+from pathlib import Path
 from contextlib import suppress
 from typing import List, Optional
 
 import toml
 
 import snapcraft
 from snapcraft import sources
-from snapcraft import shell_utils
+from snapcraft import file_utils, shell_utils
 from snapcraft.internal import errors
 
 _RUSTUP = "https://sh.rustup.rs/"
@@ -194,21 +195,76 @@ def _get_target(self) -> str:
             )
         return rust_target.format("unknown-linux", "gnu")
 
+    def _project_uses_workspace(self) -> bool:
+        cargo_toml_path = Path(self.builddir, "Cargo.toml")
+
+        try:
+            config = open(cargo_toml_path).read()
+        except FileNotFoundError:
+            raise errors.SnapcraftPluginAssertionError(
+                name=self.name, reason="missing required Cargo.toml in source directory"
+            )
+
+        return "workspace" in toml.loads(config)
+
+    def _install_workspace_artifacts(self) -> None:
+        """Install workspace artifacts."""
+        # Find artifacts in release directory.
+        release_dir = Path(self.builddir, "target", "release")
+
+        # Install binaries to bin/.
+        bins_dir = Path(self.installdir, "bin")
+        bins_dir.mkdir(parents=True, exist_ok=True)
+
+        # Install shared objects to usr/lib/<arch-triplet>.
+        # TODO: Dynamic library support needs to be properly added.
+        # Although we install libraries if we find them, they are most
+        # likely going to be missing dependencies, e.g.:
+        # /home/ubuntu/.cargo/toolchains/stable-x86_64-unknown-linux-gnu/lib/libstd-fae576517123aa4e.so
+        libs_dir = Path(self.installdir, "usr", "lib", self.project.arch_triplet)
+        libs_dir.mkdir(parents=True, exist_ok=True)
+
+        # Cargo build marks binaries and shared objects executable...
+        # Search target directory to get these and install them to the
+        # correct location (*.so to lib directory, otherwise bin directory).
+        executables = [
+            i
+            for i in release_dir.iterdir()
+            if os.path.isfile(i) and os.access(i, os.X_OK)
+        ]
+        for exe_path in executables:
+            if exe_path.name.endswith(".so"):
+                file_utils.link_or_copy(exe_path.as_posix(), libs_dir.as_posix())
+            else:
+                file_utils.link_or_copy(exe_path.as_posix(), bins_dir.as_posix())
+
     def build(self):
         super().build()
 
         # Write a minimal config.
         self._write_cargo_config()
 
-        install_cmd = [
-            self._cargo_cmd,
-            "install",
-            "--path",
-            self.builddir,
-            "--root",
-            self.installdir,
-            "--force",
-        ]
+        uses_workspaces = self._project_uses_workspace()
+        if uses_workspaces:
+            # This is a bit ugly because `cargo install` does not yet support
+            # workspaces.  Alternatively, there is a perhaps better option
+            # to use `cargo-build --out-dir`, but `--out-dir` is considered
+            # unstable and unavailable for use yet on the stable channel.  It
+            # may be better because the use of `cargo install` without `--locked`
+            # does not appear to honor Cargo.lock, while `cargo build` does by
+            # default, if it is present.
+            install_cmd = [self._cargo_cmd, "build", "--release"]
+        else:
+            install_cmd = [
+                self._cargo_cmd,
+                "install",
+                "--path",
+                self.builddir,
+                "--root",
+                self.installdir,
+                "--force",
+            ]
+
         toolchain = self._get_toolchain()
         if toolchain is not None:
             install_cmd.insert(1, "+{}".format(toolchain))
@@ -224,11 +280,16 @@ def build(self):
             install_cmd.append(" ".join(self.options.rust_features))
 
         # build and install.
-        self.run(install_cmd, env=self._build_env())
+        self.run(install_cmd, env=self._build_env(), cwd=self.builddir)
 
         # Finally, record.
         self._record_manifest()
 
+        if uses_workspaces:
+            # We need to install the workspace artifacts as a workaround until
+            # `cargo build` supports `out-dir` in "stable".
+            self._install_workspace_artifacts()
+
     def _build_env(self):
         env = os.environ.copy()
 

tests/spread/plugins/rust/snaps/rust-workspace-fib/Cargo.toml

@@ -0,0 +1,6 @@
+[workspace]
+
+members = [
+    "fib",
+    "calc-fib"
+]

tests/spread/plugins/rust/snaps/rust-workspace-fib/calc-fib/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "calc-fib"
+version = "0.1.0"
+authors = ["Chris Patterson <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+regex = "1"
+fib = { path = "../fib" }

tests/spread/plugins/rust/snaps/rust-workspace-fib/calc-fib/src/main.rs

@@ -0,0 +1,25 @@
+use std::env;
+extern crate fib;
+
+fn main() {
+    let args: Vec<String> = env::args().collect();
+
+    if args.len() < 2 {
+        eprintln!("please specify number");
+        return
+    }
+
+    let num_string = &args[1];
+    let number: i32 = match num_string.parse() {
+        Ok(n) => {
+            n
+        },
+        Err(_) => {
+            eprintln!("error: not an integer");
+            return;
+        }
+    };
+
+    let sum = fib::fib(number);
+    println!("{}", sum);
+}

tests/spread/plugins/rust/snaps/rust-workspace-fib/fib/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "fib"
+version = "0.1.0"
+authors = ["Chris Patterson <[email protected]>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]

tests/spread/plugins/rust/snaps/rust-workspace-fib/fib/src/lib.rs

@@ -0,0 +1,13 @@
+// Terribly inefficient recursive fib routine.
+pub fn fib(n: i32) -> u64 {
+    if n < 0 {
+        panic!("invalid: {}", n);
+    }
+    if n == 0 {
+        return 0;
+    } else if n == 1 {
+        return 1;
+    } else {
+        return fib(n - 1) + fib(n - 2)
+    }
+}

tests/spread/plugins/rust/snaps/rust-workspace-fib/snap/snapcraft.yaml

@@ -0,0 +1,17 @@
+name: calc-fib
+version: "1.0"
+summary: Test the rust plugin with sworkspaces.
+description: |
+  This is a basic rust snap with workspaces.
+
+grade: devel
+confinement: strict
+
+apps:
+  calc-fib:
+    command: bin/calc-fib
+
+parts:
+  calc-fib:
+    plugin: rust
+    source: .

tests/spread/plugins/rust/workspace/task.yaml

@@ -0,0 +1,36 @@
+summary: Build and run a workspace rust snap
+
+systems:
+  - ubuntu-18.04
+  - ubuntu-18.04-64
+  - ubuntu-18.04-amd64
+  - ubuntu-18.04-i386
+  - ubuntu-18.04-armhf
+  - ubuntu-16.04
+  - ubuntu-16.04-64
+  - ubuntu-16.04-amd64
+  - ubuntu-16.04-i386
+  - ubuntu-16.04-armhf
+
+environment:
+  SNAP_DIR: ../snaps/rust-workspace-fib
+
+prepare: |
+  #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
+  . "$TOOLS_DIR/snapcraft-yaml.sh"
+  set_base "$SNAP_DIR/snap/snapcraft.yaml"
+
+restore: |
+  cd "$SNAP_DIR"
+  snapcraft clean
+  rm -f ./*.snap
+
+  #shellcheck source=tests/spread/tools/snapcraft-yaml.sh
+  . "$TOOLS_DIR/snapcraft-yaml.sh"
+  restore_yaml "snap/snapcraft.yaml"
+
+execute: |
+  cd "$SNAP_DIR"
+  snapcraft
+  sudo snap install calc-fib_*.snap --dangerous
+  [ "$(calc-fib 8)" = "21" ]