feat: support workspaces for go

Signed-off-by: Sergio Schvezov <[email protected]>

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]
@@ -93,6 +94,10 @@ class GoPlugin(Plugin):
       (list of strings)
       Parameters to pass to `go generate` before building. Each item on the list
       will be a separate `go generate` call. Default is not to call `go generate`.
+    - ``go-workspace-use``
+      (list of strings)
+      Parameters for `go work use` statements to setup a workspace to consume
+      go modules from.
     """
 
     properties_class = GoPluginProperties
@@ -120,12 +125,21 @@ def get_build_commands(self) -> list[str]:
         """Return a list of commands to run during the build step."""
         options = cast(GoPluginProperties, self._options)
 
+        init_cmds: list[str] = []
+        if options.go_workspace_use:
+            # Only initialize if go.work is not there.
+            init_cmds.append("[ -f go.work ] || go work init")
+            init_cmds.append("go work use .")
+            init_cmds.extend([f"go work use {use}" for use in options.go_workspace_use])
+        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} ./...',
         ]

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

@@ -33,6 +33,18 @@ Parameters to pass to `go generate`_ before building. Each item on the list
 will be a separate ``go generate`` call. The default behavior is not to call
 ``go generate``.
 
+go-workspace-use
+~~~~~~~~~~~~~~~~
+**Type**: list of strings
+**Default** []
+
+Parameters to setup a `go workspace`_ with modules to use for the build. The
+current source is added automatically when any path is defined. Paths must be on
+the local filesystem (e.g.; within ``$CRAFT/STAGE``).
+
+The use of ``go.work`` omits the downloading of go modules.
+
+
 Environment variables
 ---------------------
 
@@ -48,7 +60,7 @@ 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 ``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
@@ -65,11 +77,17 @@ 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 ``go-workspace-use`` is defined:
+  * Call ``go work init`` if ``go.work`` is not found;
+  * Call ``go work use .`` to add the source for the part;
+  * Call ``go work use <item>`` for each item in ``go-workspace-use``;
+* If ``go-workspace-use`` is not defined, 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.
 
+If
 Examples
 --------
 
@@ -94,4 +112,4 @@ 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

tests/integration/plugins/test_go.py

@@ -114,3 +114,53 @@ 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):
+    """Test code generation via "go generate" in parts using the go plugin
+
+    The go code in the "test_go" dir uses "gen/generator.go" to create, at build time,
+    the "main.go" file that produces the final binary.
+    """
+    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: dump
+            organize:
+              "*": modules/go-flags/
+            prime:
+              - -modules
+          foo:
+            after:
+            - go-flags
+            plugin: go
+            source: {source_location}
+            go-workspace-use:
+              - $CRAFT_STAGE/modules/go-flags
+            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)
+    # This is the expected output that "gen/generator.go" sets in "main.go"
+    assert output == "hello\n"

tests/integration/plugins/test_go_workspace/go.mod

@@ -0,0 +1,8 @@
+module example/workspace
+
+go 1.23.2
+
+require (
+	github.com/jessevdk/go-flags v1.6.1 // indirect
+	golang.org/x/sys v0.25.0 // indirect
+)

tests/integration/plugins/test_go_workspace/go.sum

@@ -0,0 +1,6 @@
+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 v0.21.0 h1:rF+pYz3DAGSQAxAu1CbC7catZg4ebC4UIeIhKxBZvws=
+golang.org/x/sys v0.21.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+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 +191,18 @@ 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": ".", "go-workspace-use": ["go-flags", "go-cmp"]}
+    )
+    plugin = GoPlugin(properties=properties, part_info=part_info)
+
+    assert plugin.get_build_commands() == [
+        "[ -f go.work ] || go work init",
+        "go work use .",
+        "go work use go-flags",
+        "go work use go-cmp",
+        'go install -p "1"  ./...',
+    ]