decode DeviceRequest.Count using DecodeMapstructure

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

loader/loader.go

@@ -624,7 +624,6 @@ func createTransformHook(additionalTransformers ...Transformer) mapstructure.Dec
 		reflect.TypeOf(types.BuildConfig{}):                      transformBuildConfig,
 		reflect.TypeOf(types.DependsOnConfig{}):                  transformDependsOnConfig,
 		reflect.TypeOf(types.ExtendsConfig{}):                    transformExtendsConfig,
-		reflect.TypeOf(types.DeviceRequest{}):                    transformServiceDeviceRequest,
 		reflect.TypeOf(types.SSHConfig{}):                        transformSSHConfig,
 		reflect.TypeOf(types.IncludeConfig{}):                    transformIncludeConfig,
 	}
@@ -1087,35 +1086,6 @@ var transformServicePort TransformerFunc = func(data interface{}) (interface{},
 	}
 }
 
-var transformServiceDeviceRequest TransformerFunc = func(data interface{}) (interface{}, error) {
-	switch value := data.(type) {
-	case map[string]interface{}:
-		count, ok := value["count"]
-		if ok {
-			switch val := count.(type) {
-			case int:
-				return value, nil
-			case string:
-				if strings.ToLower(val) == "all" {
-					value["count"] = -1
-					return value, nil
-				}
-				i, err := strconv.ParseInt(val, 10, 64)
-				if err == nil {
-					value["count"] = i
-					return value, nil
-				}
-				return data, errors.Errorf("invalid string value for 'count' (the only value allowed is 'all' or a number)")
-			default:
-				return data, errors.Errorf("invalid type %T for device count", val)
-			}
-		}
-		return data, nil
-	default:
-		return data, errors.Errorf("invalid type %T for resource reservation", value)
-	}
-}
-
 var transformFileReferenceConfig TransformerFunc = func(data interface{}) (interface{}, error) {
 	switch value := data.(type) {
 	case string:

loader/loader_test.go

@@ -2129,9 +2129,9 @@ services:
           devices:
             - driver: nvidia
               capabilities: [gpu]
-              count: somestring
+              count: some_string
 `)
-	assert.ErrorContains(t, err, "invalid string value for 'count' (the only value allowed is 'all' or a number)")
+	assert.ErrorContains(t, err, `invalid value "some_string", the only value allowed is 'all' or a number`)
 }
 
 func TestServicePullPolicy(t *testing.T) {

types/device.go

@@ -0,0 +1,53 @@
+/*
+   Copyright 2020 The Compose Specification Authors.
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+*/
+
+package types
+
+import (
+	"strconv"
+	"strings"
+
+	"github.com/pkg/errors"
+)
+
+type DeviceRequest struct {
+	Capabilities []string    `yaml:"capabilities,omitempty" json:"capabilities,omitempty"`
+	Driver       string      `yaml:"driver,omitempty" json:"driver,omitempty"`
+	Count        DeviceCount `yaml:"count,omitempty" json:"count,omitempty"`
+	IDs          []string    `yaml:"device_ids,omitempty" json:"device_ids,omitempty"`
+}
+
+type DeviceCount int64
+
+func (c *DeviceCount) DecodeMapstructure(value interface{}) error {
+	switch v := value.(type) {
+	case int:
+		*c = DeviceCount(v)
+	case string:
+		if strings.ToLower(v) == "all" {
+			*c = -1
+			return nil
+		}
+		i, err := strconv.ParseInt(v, 10, 64)
+		if err != nil {
+			return errors.Errorf("invalid value %q, the only value allowed is 'all' or a number", v)
+		}
+		*c = DeviceCount(i)
+	default:
+		return errors.Errorf("invalid type %T for device count", v)
+	}
+	return nil
+}

types/types.go

@@ -584,13 +584,6 @@ type Resource struct {
 	Extensions Extensions `yaml:"#extensions,inline" json:"-"`
 }
 
-type DeviceRequest struct {
-	Capabilities []string `yaml:"capabilities,omitempty" json:"capabilities,omitempty"`
-	Driver       string   `yaml:"driver,omitempty" json:"driver,omitempty"`
-	Count        int64    `yaml:"count,omitempty" json:"count,omitempty"`
-	IDs          []string `yaml:"device_ids,omitempty" json:"device_ids,omitempty"`
-}
-
 // GenericResource represents a "user defined" resource which can
 // only be an integer (e.g: SSD=3) for a service
 type GenericResource struct {