test: add basic integration tests

Signed-off-by: Justin Chadwell <me@jedevc.com>

tests/workers/docker-container.go

@@ -0,0 +1,66 @@
+package workers
+
+import (
+	"context"
+	"os"
+	"os/exec"
+
+	"github.com/moby/buildkit/identity"
+	"github.com/moby/buildkit/util/testutil/integration"
+	"github.com/pkg/errors"
+)
+
+func InitDockerContainerWorker() {
+	integration.Register(&containerWorker{
+		id: "docker-container",
+	})
+}
+
+type containerWorker struct {
+	id string
+}
+
+func (w *containerWorker) Name() string {
+	return w.id
+}
+
+func (w *containerWorker) Rootless() bool {
+	return false
+}
+
+func (w *containerWorker) New(ctx context.Context, cfg *integration.BackendConfig) (integration.Backend, func() error, error) {
+	bk, bkclose, err := dockerWorker{id: w.id}.New(ctx, cfg)
+	if err != nil {
+		return bk, bkclose, err
+	}
+
+	name := "integration-container-" + identity.NewID()
+	cmd := exec.Command("buildx", "create",
+		"--bootstrap",
+		"--name="+name,
+		"--config="+cfg.ConfigFile,
+		"--driver=docker-container",
+		"--driver-opt=network=host",
+	)
+	cmd.Env = append(os.Environ(), "DOCKER_CONTEXT="+bk.DockerAddress())
+	if err := cmd.Run(); err != nil {
+		return nil, nil, errors.Wrapf(err, "failed to create buildx instance %s", name)
+	}
+
+	cl := func() error {
+		var err error
+		if err1 := bkclose(); err == nil {
+			err = err1
+		}
+		cmd := exec.Command("buildx", "rm", "-f", name)
+		if err1 := cmd.Run(); err == nil {
+			err = err1
+		}
+		return err
+	}
+
+	return &backend{
+		context: bk.DockerAddress(),
+		builder: name,
+	}, cl, nil
+}