From 7567e990d24481eeafc02b81de57a784d3851806 Mon Sep 17 00:00:00 2001
From: Justin Chadwell <me@jedevc.com>
Date: Wed, 24 Apr 2024 12:42:36 +0100
Subject: [PATCH] feat: interpret current arg to get current platform

Signed-off-by: Justin Chadwell <me@jedevc.com>
---
 cmd/dagger/flags.go                  | 35 ++++++++++++++++++++++++++++
 cmd/dagger/functions.go              |  1 +
 core/integration/module_call_test.go |  4 ++++
 3 files changed, 40 insertions(+)

diff --git a/cmd/dagger/flags.go b/cmd/dagger/flags.go
index a8d9e903d87..dd9b4408a4b 100644
--- a/cmd/dagger/flags.go
+++ b/cmd/dagger/flags.go
@@ -17,6 +17,7 @@ import (
 	"strconv"
 	"strings"
 
+	"github.com/containerd/containerd/platforms"
 	"github.com/moby/buildkit/util/gitutil"
 	"github.com/spf13/pflag"
 
@@ -44,6 +45,8 @@ func GetCustomFlagValue(name string) DaggerValue {
 		return &moduleSourceValue{}
 	case Module:
 		return &moduleValue{}
+	case Platform:
+		return &platformValue{}
 	}
 	return nil
 }
@@ -69,6 +72,8 @@ func GetCustomFlagValueSlice(name string) DaggerValue {
 		return &sliceValue[*moduleSourceValue]{}
 	case Module:
 		return &sliceValue[*moduleValue]{}
+	case Platform:
+		return &sliceValue[*platformValue]{}
 	}
 	return nil
 }
@@ -592,6 +597,36 @@ func (v *moduleSourceValue) Get(ctx context.Context, dag *dagger.Client, _ *dagg
 	return modConf.Source, nil
 }
 
+type platformValue struct {
+	platform string
+}
+
+func (v *platformValue) Type() string {
+	return Module
+}
+
+func (v *platformValue) Set(s string) error {
+	if s == "" {
+		return fmt.Errorf("platform cannot be empty")
+	}
+	if s == "current" {
+		s = platforms.DefaultString()
+	}
+	v.platform = s
+	return nil
+}
+
+func (v *platformValue) String() string {
+	return v.platform
+}
+
+func (v *platformValue) Get(ctx context.Context, dag *dagger.Client, _ *dagger.ModuleSource) (any, error) {
+	if v.platform == "" {
+		return nil, fmt.Errorf("platform cannot be empty")
+	}
+	return v.platform, nil
+}
+
 // AddFlag adds a flag appropriate for the argument type. Should return a
 // pointer to the value.
 func (r *modFunctionArg) AddFlag(flags *pflag.FlagSet, dag *dagger.Client) (any, error) {
diff --git a/cmd/dagger/functions.go b/cmd/dagger/functions.go
index f2e422b6e57..e5b9dc1208d 100644
--- a/cmd/dagger/functions.go
+++ b/cmd/dagger/functions.go
@@ -30,6 +30,7 @@ const (
 	CacheVolume  string = "CacheVolume"
 	ModuleSource string = "ModuleSource"
 	Module       string = "Module"
+	Platform     string = "Platform"
 )
 
 var funcGroup = &cobra.Group{
diff --git a/core/integration/module_call_test.go b/core/integration/module_call_test.go
index 4a5003ffa85..4bc46f909f5 100644
--- a/core/integration/module_call_test.go
+++ b/core/integration/module_call_test.go
@@ -5,6 +5,7 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/containerd/containerd/platforms"
 	"github.com/moby/buildkit/identity"
 	"github.com/stretchr/testify/require"
 
@@ -526,6 +527,9 @@ func (m *Test) ToPlatform(platform string) Platform {
 		out, err := modGen.With(daggerCall("from-platform", "--platform", "linux/amd64")).Stdout(ctx)
 		require.NoError(t, err)
 		require.Equal(t, "linux/amd64", out)
+		out, err = modGen.With(daggerCall("from-platform", "--platform", "current")).Stdout(ctx)
+		require.NoError(t, err)
+		require.Equal(t, platforms.DefaultString(), out)
 		_, err = modGen.With(daggerCall("from-platform", "--platform", "invalid")).Stdout(ctx)
 		require.ErrorContains(t, err, "unknown operating system or architecture")