build: warning on deprecated flags

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

build/build.go

@@ -546,7 +546,7 @@ func toSolveOpt(ctx context.Context, d driver.Driver, multiDriver bool, opt Opti
 		so.FrontendAttrs["force-network-mode"] = opt.NetworkMode
 	case "", "default":
 	default:
-		return nil, nil, errors.Errorf("network mode %q not supported by buildkit", opt.NetworkMode)
+		return nil, nil, errors.Errorf("network mode %q not supported by buildkit. You can define a custom network for your builder using the network driver-opt in buildx create.", opt.NetworkMode)
 	}
 
 	// setup extrahosts

commands/build.go

@@ -22,6 +22,7 @@ import (
 	"github.com/moby/buildkit/session/auth/authprovider"
 	"github.com/moby/buildkit/util/appcontext"
 	"github.com/pkg/errors"
+	"github.com/sirupsen/logrus"
 	"github.com/spf13/cobra"
 	"github.com/spf13/pflag"
 )
@@ -50,9 +51,6 @@ type buildOptions struct {
 	target      string
 	ulimits     *dockeropts.UlimitOpt
 	commonOptions
-
-	// unimplemented
-	squash bool
 }
 
 type commonOptions struct {
@@ -70,9 +68,6 @@ type commonOptions struct {
 }
 
 func runBuild(dockerCli command.Cli, in buildOptions) (err error) {
-	if in.squash {
-		return errors.Errorf("squash currently not implemented")
-	}
 	ctx := appcontext.Context()
 
 	ctx, end, err := tracing.TraceCurrentCommand(ctx, "build")
@@ -268,6 +263,7 @@ func buildCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 		RunE: func(cmd *cobra.Command, args []string) error {
 			options.contextPath = args[0]
 			options.builder = rootOpts.builder
+			cmd.Flags().VisitAll(checkWarnedFlags)
 			return runBuild(dockerCli, options)
 		},
 	}
@@ -324,10 +320,6 @@ func buildCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 
 	flags.Var(options.ulimits, "ulimit", "Ulimit options")
 
-	// not implemented
-	flags.BoolVar(&options.squash, "squash", false, "Squash newly built layers into a single new layer")
-	flags.MarkHidden("squash")
-
 	// hidden flags
 	var ignore string
 	var ignoreSlice []string
@@ -336,15 +328,22 @@ func buildCmd(dockerCli command.Cli, rootOpts *rootOptions) *cobra.Command {
 
 	flags.StringVar(&ignore, "cgroup-parent", "", "Optional parent cgroup for the container")
 	flags.MarkHidden("cgroup-parent")
+	//flags.SetAnnotation("cgroup-parent", "flag-warn", []string{"cgroup-parent is not implemented."})
 
 	flags.BoolVar(&ignoreBool, "compress", false, "Compress the build context using gzip")
 	flags.MarkHidden("compress")
 
 	flags.StringVar(&ignore, "isolation", "", "Container isolation technology")
 	flags.MarkHidden("isolation")
+	flags.SetAnnotation("isolation", "flag-warn", []string{"isolation flag is deprecated with BuildKit."})
 
 	flags.StringSliceVar(&ignoreSlice, "security-opt", []string{}, "Security options")
 	flags.MarkHidden("security-opt")
+	flags.SetAnnotation("security-opt", "flag-warn", []string{`security-opt flag is deprecated. "RUN --security=insecure" should be used with BuildKit.`})
+
+	flags.BoolVar(&ignoreBool, "squash", false, "Squash newly built layers into a single new layer")
+	flags.MarkHidden("squash")
+	flags.SetAnnotation("squash", "flag-warn", []string{"experimental flag squash is removed with BuildKit. You should squash inside build using a multi-stage Dockerfile for efficiency."})
 
 	flags.StringVarP(&ignore, "memory", "m", "", "Memory limit")
 	flags.MarkHidden("memory")
@@ -384,6 +383,19 @@ func commonBuildFlags(options *commonOptions, flags *pflag.FlagSet) {
 	flags.StringVar(&options.metadataFile, "metadata-file", "", "Write build result metadata to the file")
 }
 
+func checkWarnedFlags(f *pflag.Flag) {
+	if !f.Changed {
+		return
+	}
+	for t, m := range f.Annotations {
+		switch t {
+		case "flag-warn":
+			logrus.Warn(m[0])
+			break
+		}
+	}
+}
+
 func listToMap(values []string, defaultEnv bool) map[string]string {
 	result := make(map[string]string, len(values))
 	for _, value := range values {

docs/reference/buildx_create.md

@@ -131,11 +131,6 @@ Passes additional driver-specific options. Details for each driver:
     - `image=IMAGE` - Sets the container image to be used for running buildkit.
     - `network=NETMODE` - Sets the network mode for running the buildkit container.
     - `cgroup-parent=CGROUP` - Sets the cgroup parent of the buildkit container if docker is using the "cgroupfs" driver. Defaults to `/docker/buildx`.
-    - Example:
-
-      ```console
-      --driver docker-container --driver-opt image=moby/buildkit:master,network=host
-      ```
 - `kubernetes`
     - `image=IMAGE` - Sets the container image to be used for running buildkit.
     - `namespace=NS` - Sets the Kubernetes namespace. Defaults to the current namespace.
@@ -150,6 +145,30 @@ Passes additional driver-specific options. Details for each driver:
     - `qemu.install=(true|false)` - Install QEMU emulation for multi platforms support.
     - `qemu.image=IMAGE` - Sets the QEMU emulation image. Defaults to `tonistiigi/binfmt:latest`
 
+**Examples**
+
+#### Use a custom network
+
+```console
+$ docker network create foonet
+$ docker buildx create --name builder --driver docker-container --driver-opt network=foonet --use
+$ docker buildx inspect --bootstrap
+$ docker inspect buildx_buildkit_builder0 --format={{.NetworkSettings.Networks}}
+map[foonet:0xc00018c0c0]
+```
+
+#### OpenTelemetry support
+
+To capture the trace to [Jaeger](https://github.com/jaegertracing/jaeger), set
+`JAEGER_TRACE` environment variable to the collection address using the `driver-opt`:
+
+```console
+$ docker run -d --name jaeger -p 6831:6831/udp -p 16686:16686 jaegertracing/all-in-one
+$ docker buildx create --name builder --driver docker-container --driver-opt network=host --driver-opt env.JAEGER_TRACE=localhost:6831 --use
+$ docker buildx inspect --bootstrap
+# buildx command should be traced at http://127.0.0.1:16686/
+```
+
 ### <a name="leave"></a> Remove a node from a builder (--leave)
 
 The `--leave` flag changes the action of the command to remove a node from a