test: add basic integration tests

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

tests/workers/docker.go

@@ -0,0 +1,64 @@
+package workers
+
+import (
+	"context"
+	"os/exec"
+
+	"github.com/moby/buildkit/identity"
+	"github.com/moby/buildkit/util/testutil/integration"
+	"github.com/pkg/errors"
+)
+
+func InitDockerWorker() {
+	integration.Register(&dockerWorker{
+		id: "docker",
+	})
+}
+
+type dockerWorker struct {
+	id string
+}
+
+func (c dockerWorker) Name() string {
+	return c.id
+}
+
+func (c dockerWorker) Rootless() bool {
+	return false
+}
+
+func (c dockerWorker) New(ctx context.Context, cfg *integration.BackendConfig) (b integration.Backend, cl func() error, err error) {
+	moby := integration.Moby{
+		ID: c.id,
+	}
+	bk, bkclose, err := moby.New(ctx, cfg)
+	if err != nil {
+		return bk, cl, err
+	}
+
+	name := "integration-" + identity.NewID()
+	cmd := exec.Command("docker", "context", "create",
+		name,
+		"--docker", "host="+bk.DockerAddress(),
+	)
+	if err := cmd.Run(); err != nil {
+		return nil, cl, 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("docker", "context", "rm", "-f", name)
+		if err1 := cmd.Run(); err1 != nil {
+			err = errors.Wrapf(err1, "failed to remove buildx instance %s", name)
+		}
+		return err
+	}
+
+	return &backend{
+		builder: name,
+		context: name,
+	}, cl, nil
+}