bake: restore previous override merge behavior

For array fields, overrides are merged together
but override is not merged with the target. If merging
with target is desired we can add support for
overrides with += operator in the future.

Signed-off-by: Tonis Tiigi <tonistiigi@gmail.com>

bake/bake.go

@@ -31,8 +31,8 @@ type File struct {
 }
 
 type Override struct {
-	Key   string
-	Value string
+	Value    string
+	ArrValue []string
 }
 
 func defaultFilenames() []string {
@@ -246,8 +246,8 @@ func (c Config) expandTargets(pattern string) ([]string, error) {
 	return names, nil
 }
 
-func (c Config) newOverrides(v []string) (map[string][]Override, error) {
-	m := map[string][]Override{}
+func (c Config) newOverrides(v []string) (map[string]map[string]Override, error) {
+	m := map[string]map[string]Override{}
 	for _, v := range v {
 
 		parts := strings.SplitN(v, "=", 2)
@@ -269,16 +269,19 @@ func (c Config) newOverrides(v []string) (map[string][]Override, error) {
 		kk := strings.SplitN(parts[0], ".", 2)
 
 		for _, name := range names {
-			t := m[name]
-
-			o := Override{
-				Key: kk[1],
-			}
-			if len(parts) == 2 {
-				o.Value = parts[1]
+			t, ok := m[name]
+			if !ok {
+				t = map[string]Override{}
+				m[name] = t
 			}
 
+			o := t[kk[1]]
+
 			switch keys[1] {
+			case "output", "cache-to", "cache-from", "tags", "platform", "secrets", "ssh":
+				if len(parts) == 2 {
+					o.ArrValue = append(o.ArrValue, parts[1])
+				}
 			case "args":
 				if len(keys) != 3 {
 					return nil, errors.Errorf("invalid key %s, args requires name", parts[0])
@@ -290,11 +293,14 @@ func (c Config) newOverrides(v []string) (map[string][]Override, error) {
 					}
 					o.Value = v
 				}
+				fallthrough
+			default:
+				if len(parts) == 2 {
+					o.Value = parts[1]
+				}
 			}
 
-			t = append(t, o)
-
-			m[name] = t
+			t[kk[1]] = o
 		}
 	}
 	return m, nil
@@ -326,7 +332,7 @@ func (c Config) group(name string, visited map[string]struct{}) []string {
 	return targets
 }
 
-func (c Config) ResolveTarget(name string, overrides map[string][]Override) (*Target, error) {
+func (c Config) ResolveTarget(name string, overrides map[string]map[string]Override) (*Target, error) {
 	t, err := c.target(name, map[string]struct{}{}, overrides)
 	if err != nil {
 		return nil, err
@@ -342,7 +348,7 @@ func (c Config) ResolveTarget(name string, overrides map[string][]Override) (*Ta
 	return t, nil
 }
 
-func (c Config) target(name string, visited map[string]struct{}, overrides map[string][]Override) (*Target, error) {
+func (c Config) target(name string, visited map[string]struct{}, overrides map[string]map[string]Override) (*Target, error) {
 	if _, ok := visited[name]; ok {
 		return nil, nil
 	}
@@ -476,10 +482,10 @@ func (t *Target) Merge(t2 *Target) {
 	t.Inherits = append(t.Inherits, t2.Inherits...)
 }
 
-func (t *Target) AddOverrides(overrides []Override) error {
-	for _, o := range overrides {
+func (t *Target) AddOverrides(overrides map[string]Override) error {
+	for key, o := range overrides {
 		value := o.Value
-		keys := strings.SplitN(o.Key, ".", 2)
+		keys := strings.SplitN(key, ".", 2)
 		switch keys[0] {
 		case "context":
 			t.Context = &value
@@ -503,21 +509,21 @@ func (t *Target) AddOverrides(overrides []Override) error {
 			}
 			t.Labels[keys[1]] = value
 		case "tags":
-			t.Tags = append(t.Tags, value)
+			t.Tags = o.ArrValue
 		case "cache-from":
-			t.CacheFrom = append(t.CacheFrom, value)
+			t.CacheFrom = o.ArrValue
 		case "cache-to":
-			t.CacheTo = append(t.CacheTo, value)
+			t.CacheTo = o.ArrValue
 		case "target":
 			t.Target = &value
 		case "secrets":
-			t.Secrets = append(t.Secrets, value)
+			t.Secrets = o.ArrValue
 		case "ssh":
-			t.SSH = append(t.SSH, value)
+			t.SSH = o.ArrValue
 		case "platform":
-			t.Platforms = append(t.Platforms, value)
+			t.Platforms = o.ArrValue
 		case "output":
-			t.Outputs = append(t.Outputs, value)
+			t.Outputs = o.ArrValue
 		case "no-cache":
 			noCache, err := strconv.ParseBool(value)
 			if err != nil {