bake: fix missing omitempty and optional tags for network field

Signed-off-by: CrazyMax <1951866+crazy-max@users.noreply.github.com>

bake/bake.go

@@ -704,7 +704,7 @@ type Target struct {
 	Outputs          []string           `json:"output,omitempty" hcl:"output,optional" cty:"output"`
 	Pull             *bool              `json:"pull,omitempty" hcl:"pull,optional" cty:"pull"`
 	NoCache          *bool              `json:"no-cache,omitempty" hcl:"no-cache,optional" cty:"no-cache"`
-	NetworkMode      *string            `json:"network" hcl:"network" cty:"network"`
+	NetworkMode      *string            `json:"network,omitempty" hcl:"network,optional" cty:"network"`
 	NoCacheFilter    []string           `json:"no-cache-filter,omitempty" hcl:"no-cache-filter,optional" cty:"no-cache-filter"`
 	ShmSize          *string            `json:"shm-size,omitempty" hcl:"shm-size,optional"`
 	Ulimits          []string           `json:"ulimits,omitempty" hcl:"ulimits,optional"`

tests/bake.go

@@ -103,6 +103,26 @@ target "build" {
 	require.Equal(t, ".", *def.Target["build"].Context)
 	require.Equal(t, "Dockerfile", *def.Target["build"].Dockerfile)
 	require.Equal(t, map[string]*string{"HELLO": ptrstr("foo")}, def.Target["build"].Args)
+
+	require.Equal(t, `{
+  "group": {
+    "default": {
+      "targets": [
+        "build"
+      ]
+    }
+  },
+  "target": {
+    "build": {
+      "context": ".",
+      "dockerfile": "Dockerfile",
+      "args": {
+        "HELLO": "foo"
+      }
+    }
+  }
+}
+`, stdout.String())
 }
 
 func testBakeLocal(t *testing.T, sb integration.Sandbox) {