make HostsLists a map[string]string to better handle merging config

Signed-off-by: Nicolas De Loof <[email protected]>

Author: ndeloof

loader/full-struct_test.go

@@ -178,9 +178,9 @@ func services(workingDir, homeDir string) []types.ServiceConfig {
 				"project_db_1:mysql",
 				"project_db_1:postgresql",
 			},
-			ExtraHosts: []string{
-				"somehost:162.242.195.82",
-				"otherhost:50.31.209.229",
+			ExtraHosts: types.HostsList{
+				"somehost":  "162.242.195.82",
+				"otherhost": "50.31.209.229",
 			},
 			Extensions: map[string]interface{}{
 				"x-bar": "baz",
@@ -700,8 +700,8 @@ services:
     - project_db_1:mysql
     - project_db_1:postgresql
     extra_hosts:
-    - somehost:162.242.195.82
-    - otherhost:50.31.209.229
+      otherhost: 50.31.209.229
+      somehost: 162.242.195.82
     hostname: foo
     healthcheck:
       test:
@@ -1270,10 +1270,10 @@ func fullExampleJSON(workingDir, homeDir string) string {
         "project_db_1:mysql",
         "project_db_1:postgresql"
       ],
-      "extra_hosts": [
-        "somehost:162.242.195.82",
-        "otherhost:50.31.209.229"
-      ],
+      "extra_hosts": {
+        "otherhost": "50.31.209.229",
+        "somehost": "162.242.195.82"
+      },
       "hostname": "foo",
       "healthcheck": {
         "test": [

loader/loader.go

@@ -24,7 +24,6 @@ import (
 	"path/filepath"
 	"reflect"
 	"regexp"
-	"sort"
 	"strconv"
 	"strings"
 	"time"
@@ -385,7 +384,7 @@ func createTransformHook(additionalTransformers ...Transformer) mapstructure.Dec
 		reflect.TypeOf(types.MappingWithEquals{}):                transformMappingOrListFunc("=", true),
 		reflect.TypeOf(types.Labels{}):                           transformMappingOrListFunc("=", false),
 		reflect.TypeOf(types.MappingWithColon{}):                 transformMappingOrListFunc(":", false),
-		reflect.TypeOf(types.HostsList{}):                        transformListOrMappingFunc(":", false),
+		reflect.TypeOf(types.HostsList{}):                        transformMappingOrListFunc(":", false),
 		reflect.TypeOf(types.ServiceVolumeConfig{}):              transformServiceVolumeConfig,
 		reflect.TypeOf(types.BuildConfig{}):                      transformBuildConfig,
 		reflect.TypeOf(types.Duration(0)):                        transformStringToDuration,
@@ -1060,22 +1059,6 @@ func transformMappingOrListFunc(sep string, allowNil bool) TransformerFunc {
 	}
 }
 
-func transformListOrMappingFunc(sep string, allowNil bool) TransformerFunc {
-	return func(data interface{}) (interface{}, error) {
-		return transformListOrMapping(data, sep, allowNil)
-	}
-}
-
-func transformListOrMapping(listOrMapping interface{}, sep string, allowNil bool) (interface{}, error) {
-	switch value := listOrMapping.(type) {
-	case map[string]interface{}:
-		return toStringList(value, sep, allowNil), nil
-	case []interface{}:
-		return listOrMapping, nil
-	}
-	return nil, errors.Errorf("expected a map or a list, got %T: %#v", listOrMapping, listOrMapping)
-}
-
 func transformMappingOrList(mappingOrList interface{}, sep string, allowNil bool) (interface{}, error) {
 	switch value := mappingOrList.(type) {
 	case map[string]interface{}:
@@ -1168,15 +1151,3 @@ func toString(value interface{}, allowNil bool) interface{} {
 		return ""
 	}
 }
-
-func toStringList(value map[string]interface{}, separator string, allowNil bool) []string {
-	var output []string
-	for key, value := range value {
-		if value == nil && !allowNil {
-			continue
-		}
-		output = append(output, fmt.Sprintf("%s%s%s", key, separator, value))
-	}
-	sort.Strings(output)
-	return output
-}

loader/loader_test.go

@@ -1232,8 +1232,8 @@ services:
 	assert.NilError(t, err)
 
 	expected := types.HostsList{
-		"alpha:50.31.209.229",
-		"zulu:162.242.195.82",
+		"alpha": "50.31.209.229",
+		"zulu":  "162.242.195.82",
 	}
 
 	assert.Assert(t, is.Len(config.Services, 1))
@@ -1246,16 +1246,14 @@ services:
   web:
     image: busybox
     extra_hosts:
-      - "zulu:162.242.195.82"
       - "alpha:50.31.209.229"
       - "zulu:ff02::1"
 `)
 	assert.NilError(t, err)
 
 	expected := types.HostsList{
-		"zulu:162.242.195.82",
-		"alpha:50.31.209.229",
-		"zulu:ff02::1",
+		"alpha": "50.31.209.229",
+		"zulu":  "ff02::1",
 	}
 
 	assert.Assert(t, is.Len(config.Services, 1))

loader/merge_test.go

@@ -1256,3 +1256,28 @@ func TestMergeEnvironments(t *testing.T) {
 	assert.Assert(t, *env["NAME"] == "DEV")
 	assert.Assert(t, env["VALUE"] == nil)
 }
+
+func TestMergeExtraHosts(t *testing.T) {
+	base := types.HostsList{
+		"kept":              "192.168.1.100",
+		"extra1.domain.org": "192.168.1.101",
+		"extra2.domain.org": "192.168.1.102",
+	}
+	override := types.HostsList{
+		"extra1.domain.org": "10.0.0.1",
+		"extra2.domain.org": "10.0.0.2",
+		"added":             "10.0.0.3",
+	}
+	err := mergo.Merge(&base, &override, mergo.WithOverride)
+	assert.NilError(t, err)
+	assert.DeepEqual(
+		t,
+		base,
+		types.HostsList{
+			"kept":              "192.168.1.100",
+			"extra1.domain.org": "10.0.0.1",
+			"extra2.domain.org": "10.0.0.2",
+			"added":             "10.0.0.3",
+		},
+	)
+}

types/types.go

@@ -468,7 +468,16 @@ func (s SSHKey) MarshalJSON() ([]byte, error) {
 type MappingWithColon map[string]string
 
 // HostsList is a list of colon-separated host-ip mappings
-type HostsList []string
+type HostsList map[string]string
+
+// AsList return host-ip mappings as a list of colon-separated strings
+func (h HostsList) AsList() []string {
+	l := make([]string, 0, len(h))
+	for k, v := range h {
+		l = append(l, fmt.Sprintf("%s:%s", k, v))
+	}
+	return l
+}
 
 // LoggingConfig the logging configuration for a service
 type LoggingConfig struct {