bake: initial implementation

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

bake/compose.go

@@ -0,0 +1,68 @@
+package bake
+
+import (
+	"github.com/docker/cli/cli/compose/loader"
+	composetypes "github.com/docker/cli/cli/compose/types"
+)
+
+func parseCompose(dt []byte) (*composetypes.Config, error) {
+	parsed, err := loader.ParseYAML([]byte(dt))
+	if err != nil {
+		return nil, err
+	}
+	return loader.Load(composetypes.ConfigDetails{
+		ConfigFiles: []composetypes.ConfigFile{
+			{
+				Config: parsed,
+			},
+		},
+	})
+}
+
+func ParseCompose(dt []byte) (*Config, error) {
+	cfg, err := parseCompose(dt)
+	if err != nil {
+		return nil, err
+	}
+
+	var c Config
+	if len(cfg.Services) > 0 {
+		c.Group = map[string]Group{}
+		c.Target = map[string]Target{}
+
+		var g Group
+
+		for _, s := range cfg.Services {
+			g.Targets = append(g.Targets, s.Name)
+			t := Target{
+				Context:    s.Build.Context,
+				Dockerfile: s.Build.Dockerfile,
+				Labels:     s.Build.Labels,
+				Args:       toMap(s.Build.Args),
+				CacheFrom:  s.Build.CacheFrom,
+				// TODO: add platforms
+			}
+			if s.Build.Target != "" {
+				t.Target = &s.Build.Target
+			}
+			if s.Image != "" {
+				t.Tags = []string{s.Image}
+			}
+			c.Target[s.Name] = t
+		}
+		c.Group["default"] = g
+
+	}
+
+	return &c, nil
+}
+
+func toMap(in composetypes.MappingWithEquals) map[string]string {
+	m := map[string]string{}
+	for k, v := range in {
+		if v != nil {
+			m[k] = *v
+		}
+	}
+	return m
+}