feat: support workspaces for go

.github/workflows/tests.yaml

@@ -85,8 +85,8 @@ jobs:
           echo "::group::apt install"
           sudo apt install -y ninja-build cmake scons \
                               autoconf automake autopoint gcc git gperf help2man libtool texinfo
-          # Remove newer go and install regular version for 20.04
-          sudo apt install -y golang
+          # Install go from the Snap Store
+          go_job=$(sudo snap install --no-wait --classic go)
           # Install RPM dependencies for RPM tests
           sudo apt install rpm
           # Install poetry. From pipx on focal, from apt on newer systems.
@@ -96,6 +96,7 @@ jobs:
           else
             sudo apt-get install -y python3-poetry
           fi
+          snap watch $go_job
           # Ensure we don't have dotnet installed, to properly test dotnet-deps
           # Based on https://github.com/actions/runner-images/blob/main/images/linux/scripts/installers/dotnetcore-sdk.sh
           sudo apt remove -y dotnet-* || true
@@ -159,11 +160,12 @@ jobs:
           echo "::group::snap install"
           sudo snap install --no-wait core20
           sudo snap install chisel --channel latest/candidate --no-wait
+          sudo snap install go --classic --no-wait
           echo "::endgroup::"
           echo "::group::apt install"
           sudo apt install -y ninja-build cmake scons qt5-qmake p7zip \
                               autoconf automake autopoint gcc git gperf help2man libtool texinfo \
-                              curl findutils pkg-config golang rpm \
+                              curl findutils pkg-config rpm \
                               findutils python3-dev python3-venv
           echo "::endgroup::"
           echo "::group::dotnet removal"

craft_parts/plugins/go_plugin.py

@@ -37,6 +37,7 @@ class GoPluginProperties(PluginProperties, frozen=True):
 
     go_buildtags: list[str] = []
     go_generate: list[str] = []
+    go_workspace_use: list[str] = []
 
     # part properties required by the plugin
     source: str  # pyright: ignore[reportGeneralTypeIssues]
@@ -120,12 +121,22 @@ def get_build_commands(self) -> list[str]:
         """Return a list of commands to run during the build step."""
         options = cast(GoPluginProperties, self._options)
 
+        # Matches go-use plugin expectation.
+        workspace_dir = self._part_info._project_info.dirs.parts_dir
+        workspace = workspace_dir / "work.go"
+
+        init_cmds: list[str] = []
+        if workspace:
+            init_cmds.append(f"go work use {self._part_info.part_build_dir}")
+        else:
+            init_cmds.append("go mod download all")
+
         tags = f"-tags={','.join(options.go_buildtags)}" if options.go_buildtags else ""
 
         generate_cmds: list[str] = [f"go generate {cmd}" for cmd in options.go_generate]
 
         return [
-            "go mod download all",
+            *init_cmds,
             *generate_cmds,
             f'go install -p "{self._part_info.parallel_build_count}" {tags} ./...',
         ]

craft_parts/plugins/go_use_plugin.py

@@ -0,0 +1,83 @@
+# -*- Mode:Python; indent-tabs-mode:nil; tab-width:4 -*-
+#
+# Copyright 2020-2021,2024 Canonical Ltd.
+#
+# This program is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser 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
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""The Go Use plugin."""
+
+import logging
+from typing import Literal
+
+from overrides import override
+
+from craft_parts import errors
+
+from .base import Plugin
+from .properties import PluginProperties
+from .go_plugin import GoPluginEnvironmentValidator
+
+logger = logging.getLogger(__name__)
+
+
+class GoUsePluginProperties(PluginProperties, frozen=True):
+    """The part properties used by the Go Use plugin."""
+
+    plugin: Literal["go-use"] = "go-use"
+
+    # part properties required by the plugin
+    source: str  # pyright: ignore[reportGeneralTypeIssues]
+
+
+class GoUsePlugin(Plugin):
+    """A plugin to to setup the source into a go workspace.
+
+    The go plugin requires a go compiler installed on your system. This can
+    be achieved by adding the appropriate golang package to ``build-packages``,
+    or to have it installed or built in a different part. In this case, the
+    name of the part supplying the go compiler must be "go".
+    """
+
+    properties_class = GoUsePluginProperties
+    validator_class = GoPluginEnvironmentValidator
+
+    @classmethod
+    def get_out_of_source_build(cls) -> bool:
+        """Return whether the plugin performs out-of-source-tree builds."""
+        return True
+
+    @override
+    def get_build_snaps(self) -> set[str]:
+        """Return a set of required snaps to install in the build environment."""
+        return set()
+
+    @override
+    def get_build_packages(self) -> set[str]:
+        """Return a set of required packages to install in the build environment."""
+        return set()
+
+    @override
+    def get_build_environment(self) -> dict[str, str]:
+        """Return a dictionary with the environment to use in the build step."""
+        return {}
+
+    @override
+    def get_build_commands(self) -> list[str]:
+        """Return a list of commands to run during the build step."""
+        # Set the go workspace directory to live at the root of all parts.
+        workspace_dir = self._part_info._project_info.dirs.parts_dir
+
+        return [
+            f"[ -f '{workspace_dir}' ] || (cd {workspace_dir} && go work init)",
+            f"go work use {self._part_info.part_src_dir}",
+        ]

craft_parts/plugins/plugins.py

@@ -26,6 +26,7 @@
 from .dotnet_plugin import DotnetPlugin
 from .dump_plugin import DumpPlugin
 from .go_plugin import GoPlugin
+from .go_use_plugin import GoUsePlugin
 from .make_plugin import MakePlugin
 from .maven_plugin import MavenPlugin
 from .meson_plugin import MesonPlugin
@@ -54,6 +55,7 @@
     "dotnet": DotnetPlugin,
     "dump": DumpPlugin,
     "go": GoPlugin,
+    "go-use": GoUsePlugin,
     "make": MakePlugin,
     "maven": MavenPlugin,
     "meson": MesonPlugin,

docs/common/craft-parts/reference/plugins/go_plugin.rst

@@ -65,7 +65,11 @@ How it works
 
 During the build step the plugin performs the following actions:
 
-* Call ``go mod download all`` to find and download all necessary modules;
+* If a `go workspace`_ has been setup by use of the :ref:`go-use <craft_parts_go_use_plugin>`
+  plugin,
+  call ``go work use <build-dir>`` to add the source for the part to the workspace;
+* If not operating in the context of  a `go workspace`_, call ``go mod download all``
+  to find and download all necessary modules;
 * Call ``go generate <item>`` for each item in ``go-generate``;
 * Call ``go install  ./...``, passing the items in ``go-buildtags`` through the
   ``--tags`` parameter.
@@ -94,4 +98,4 @@ The following snippet declares a part using the ``go`` plugin. It uses the stabl
 .. _Build tags: https://pkg.go.dev/cmd/go#hdr-Build_constraints
 .. _Go: https://go.dev/
 .. _go generate: https://go.dev/blog/generate
-
+.. _go workspace: https://go.dev/blog/get-familiar-with-workspaces

docs/common/craft-parts/reference/plugins/go_use_plugin.rst

@@ -0,0 +1,71 @@
+.. _craft_parts_go_use_plugin:
+
+Go Use plugin
+=============
+
+The Go plugin allows for setting up a `go workspace`_ for `Go`_ modules. It is
+a companion plugin meant to be used with the :ref:`Go plugin <craft_parts_go_plugin>`.
+Use of this plugin sets up ``go.work`` and affects all parts.
+
+Keywords
+--------
+
+There are no additional keywords to the the common :ref:`plugin <part-properties-plugin>`
+and :ref:`sources <part-properties-sources>` keywords.
+
+.. _go-use-details-begin:
+
+Dependencies
+------------
+
+The Go plugin needs the ``go`` executable to build Go programs but does not
+provision it by itself, to allow flexibility in the choice of compiler version.
+
+Common means of providing ``go`` are:
+
+* The ``golang`` Ubuntu package, declared as a ``build-package``.
+* The ``go`` snap, declared as a ``build-snap`` from the desired channel.
+
+Another alternative is to define another part with the name ``go-deps``, and
+declare that the part using the ``go`` plugin comes :ref:`after <after>` the
+``go-deps`` part. In this case, the plugin will assume that this new part will
+stage the ``go`` executable to be used in the build step. This can be useful,
+for example, in cases where a specific, unreleased version of ``go`` is desired
+but unavailable as a snap or an Ubuntu package.
+
+.. _go-use-details-end:
+
+How it works
+------------
+
+During the build step the plugin performs the following actions:
+
+* Setup a `go workspace`_ if ``go.work`` has not been setup;
+* Call ``go work use <source-dir>`` to add the source for the part to the workspace;
+
+Examples
+--------
+
+The following snippet declares a parts named ``go-flags`` using the ``go-use`` plugin and
+a ``hello`` part that declares this ``go-flags``` in its ``go.mod`` using the ``go`` plugin.
+Correct ordering is achieved with the use of the ``after`` keyword in the ``hello`` part.
+
+.. code-block:: yaml
+
+    parts:
+      go-flags:
+        source: https://github.com/jessevdk/go-flags.git
+        plugin: go-use
+      hello:
+        build-snaps:
+          - go/1.22/stable
+        plugin: go
+        source: .
+        after:
+        - go-flags
+
+
+.. _Build tags: https://pkg.go.dev/cmd/go#hdr-Build_constraints
+.. _Go: https://go.dev/
+.. _go generate: https://go.dev/blog/generate
+.. _go workspace: https://go.dev/blog/get-familiar-with-workspaces

docs/reference/plugins.rst

@@ -16,6 +16,7 @@ lifecycle.
    /common/craft-parts/reference/plugins/cmake_plugin.rst
    /common/craft-parts/reference/plugins/dump_plugin.rst
    /common/craft-parts/reference/plugins/go_plugin.rst
+   /common/craft-parts/reference/plugins/go_use_plugin.rst
    /common/craft-parts/reference/plugins/make_plugin.rst
    /common/craft-parts/reference/plugins/maven_plugin.rst
    /common/craft-parts/reference/plugins/meson_plugin.rst

tests/integration/plugins/test_go.py

@@ -114,3 +114,41 @@ def test_go_generate(new_dir, partitions):
     output = subprocess.check_output([str(binary)], text=True)
     # This is the expected output that "gen/generator.go" sets in "main.go"
     assert output == "This is a generated line\n"
+
+
+def test_go_workspace_use(new_dir, partitions):
+    source_location = Path(__file__).parent / "test_go_workspace"
+
+    parts_yaml = textwrap.dedent(
+        f"""
+        parts:
+          go-flags:
+            source: https://github.com/jessevdk/go-flags.git
+            plugin: go-use
+          hello:
+            after:
+            - go-flags
+            plugin: go
+            source: {source_location}
+            build-environment:
+              - GO111MODULE: "on"
+        """
+    )
+    parts = yaml.safe_load(parts_yaml)
+    lf = LifecycleManager(
+        parts,
+        application_name="test_go",
+        cache_dir=new_dir,
+        work_dir=new_dir,
+        partitions=partitions,
+    )
+    actions = lf.plan(Step.PRIME)
+
+    with lf.action_executor() as ctx:
+        ctx.execute(actions)
+
+    binary = Path(lf.project_info.prime_dir, "bin", "workspace")
+    assert binary.is_file()
+
+    output = subprocess.check_output([str(binary), "--say=hello"], text=True)
+    assert output == "hello\n"

tests/integration/plugins/test_go_workspace/go.mod

@@ -0,0 +1,7 @@
+module example/workspace
+
+go 1.23
+
+require github.com/jessevdk/go-flags v1.6.1
+
+require golang.org/x/sys v0.25.0 // indirect

tests/integration/plugins/test_go_workspace/go.sum

@@ -0,0 +1,4 @@
+github.com/jessevdk/go-flags v1.6.1 h1:Cvu5U8UGrLay1rZfv/zP7iLpSHGUZ/Ou68T0iX1bBK4=
+github.com/jessevdk/go-flags v1.6.1/go.mod h1:Mk8T1hIAWpOiJiHa9rJASDK2UGWji0EuPGBnNLMooyc=
+golang.org/x/sys v0.25.0 h1:r+8e+loiHxRqhXVl6ML1nO3l1+oFoWbnlu2Ehimmi34=
+golang.org/x/sys v0.25.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

tests/integration/plugins/test_go_workspace/main.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"fmt"
+	"github.com/jessevdk/go-flags"
+	"os"
+)
+
+type Options struct {
+	Say string `long:"say" description:"What to say" optional:"yes" default:"Hello world"`
+}
+
+var options Options
+
+var parser = flags.NewParser(&options, flags.Default)
+
+func main() {
+	if _, err := parser.Parse(); err != nil {
+		switch flagsErr := err.(type) {
+		case flags.ErrorType:
+			if flagsErr == flags.ErrHelp {
+				os.Exit(0)
+			}
+			os.Exit(1)
+		default:
+			os.Exit(1)
+		}
+	}
+	fmt.Printf("%s\n", options.Say)
+}

tests/unit/plugins/test_go_plugin.py

@@ -191,3 +191,20 @@ def test_get_build_commands_go_generate(part_info):
         "go generate -x b",
         'go install -p "1"  ./...',
     ]
+
+
+def test_get_build_commands_go_workspace_use(part_info):
+    properties = GoPlugin.properties_class.unmarshal({"source": "."})
+    plugin = GoPlugin(properties=properties, part_info=part_info)
+
+    workspace_dir = plugin._part_info._project_info.dirs.parts_dir
+    workspace = workspace_dir / "work.go"
+    workspace_dir.mkdir(parents=True)
+    workspace.touch()
+
+    assert plugin.get_build_commands() == [
+        f"go work use {plugin._part_info.part_build_dir}",
+        "go work use go-flags",
+        "go work use go-cmp",
+        'go install -p "1"  ./...',
+    ]