Add NetworkMode to bake target

Allows specification of network mode in a bake target.

Fixes #848

Signed-off-by: Zachary Povey <zachary.povey@autotrader.co.uk>

bake/bake.go

@@ -426,6 +426,7 @@ type Target struct {
 	Outputs          []string          `json:"output,omitempty" hcl:"output,optional"`
 	Pull             *bool             `json:"pull,omitempty" hcl:"pull,optional"`
 	NoCache          *bool             `json:"no-cache,omitempty" hcl:"no-cache,optional"`
+	NetworkMode      *string           `json:"network,omitempty" hcl:"network,optional"`
 
 	// IMPORTANT: if you add more fields here, do not forget to update newOverrides and README.
 }
@@ -492,6 +493,9 @@ func (t *Target) Merge(t2 *Target) {
 	if t2.NoCache != nil {
 		t.NoCache = t2.NoCache
 	}
+	if t2.NetworkMode != nil {
+		t.NetworkMode = t2.NetworkMode
+	}
 	t.Inherits = append(t.Inherits, t2.Inherits...)
 }
 
@@ -563,6 +567,8 @@ func (t *Target) AddOverrides(overrides map[string]Override) error {
 					}
 				}
 			}
+		case "network":
+			t.NetworkMode = &o.Value
 		default:
 			return errors.Errorf("unknown key: %s", keys[0])
 		}
@@ -632,6 +638,10 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 	if t.Pull != nil {
 		pull = *t.Pull
 	}
+	networkMode := ""
+	if t.NetworkMode != nil {
+		networkMode = *t.NetworkMode
+	}
 
 	bi := build.Inputs{
 		ContextPath:    contextPath,
@@ -648,12 +658,13 @@ func toBuildOpt(t *Target, inp *Input) (*build.Options, error) {
 	t.Context = &bi.ContextPath
 
 	bo := &build.Options{
-		Inputs:    bi,
-		Tags:      t.Tags,
-		BuildArgs: t.Args,
-		Labels:    t.Labels,
-		NoCache:   noCache,
-		Pull:      pull,
+		Inputs:      bi,
+		Tags:        t.Tags,
+		BuildArgs:   t.Args,
+		Labels:      t.Labels,
+		NoCache:     noCache,
+		Pull:        pull,
+		NetworkMode: networkMode,
 	}
 
 	platforms, err := platformutil.Parse(t.Platforms)

bake/compose.go

@@ -79,7 +79,8 @@ func ParseCompose(dt []byte) (*Config, error) {
 					val, ok := cfg.Environment[val]
 					return val, ok
 				})),
-				CacheFrom: s.Build.CacheFrom,
+				CacheFrom:   s.Build.CacheFrom,
+				NetworkMode: &s.Build.Network,
 			}
 			if err = t.composeExtTarget(s.Build.Extensions); err != nil {
 				return nil, err

bake/compose_test.go

@@ -19,6 +19,8 @@ services:
     build:
       context: ./dir
       dockerfile: Dockerfile-alternate
+      network:
+        none
       args:
         buildno: 123
 `)
@@ -43,6 +45,7 @@ services:
 	require.Equal(t, "Dockerfile-alternate", *c.Targets[1].Dockerfile)
 	require.Equal(t, 1, len(c.Targets[1].Args))
 	require.Equal(t, "123", c.Targets[1].Args["buildno"])
+	require.Equal(t, "none", *c.Targets[1].NetworkMode)
 }
 
 func TestNoBuildOutOfTreeService(t *testing.T) {

bake/hcl_test.go

@@ -36,6 +36,7 @@ func TestHCLBasic(t *testing.T) {
 
 		target "webapp-plus" {
 			inherits = ["webapp", "cross"]
+			network = "host"
 			args = {
 				IAMCROSS = "true"
 			}
@@ -63,6 +64,7 @@ func TestHCLBasic(t *testing.T) {
 	require.Equal(t, c.Targets[3].Name, "webapp-plus")
 	require.Equal(t, 1, len(c.Targets[3].Args))
 	require.Equal(t, map[string]string{"IAMCROSS": "true"}, c.Targets[3].Args)
+	require.Equal(t, "host", *c.Targets[3].NetworkMode)
 }
 
 func TestHCLBasicInJSON(t *testing.T) {
@@ -93,6 +95,7 @@ func TestHCLBasicInJSON(t *testing.T) {
 				},
 				"webapp-plus": {
 					"inherits": ["webapp", "cross"],
+					"network": "host",
 					"args": {
 						"IAMCROSS": "true"
 					}
@@ -123,6 +126,7 @@ func TestHCLBasicInJSON(t *testing.T) {
 	require.Equal(t, c.Targets[3].Name, "webapp-plus")
 	require.Equal(t, 1, len(c.Targets[3].Args))
 	require.Equal(t, map[string]string{"IAMCROSS": "true"}, c.Targets[3].Args)
+	require.Equal(t, "host", *c.Targets[3].NetworkMode)
 }
 
 func TestHCLWithFunctions(t *testing.T) {

docs/reference/buildx_bake.md

@@ -291,7 +291,7 @@ $ docker buildx bake --set foo*.no-cache              # bypass caching only for
 
 Complete list of overridable fields:
 `args`, `cache-from`, `cache-to`, `context`, `dockerfile`, `labels`, `no-cache`,
-`output`, `platform`, `pull`, `secrets`, `ssh`, `tags`, `target`
+`output`, `platform`, `pull`, `secrets`, `ssh`, `tags`, `target`, `network`
 
 ### File definition