test: add basic integration tests

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

vendor/github.com/moby/buildkit/util/testutil/integration/oci.go

@@ -0,0 +1,86 @@
+package integration
+
+import (
+	"context"
+	"fmt"
+	"log"
+	"os"
+	"runtime"
+
+	"github.com/moby/buildkit/util/bklog"
+	"github.com/pkg/errors"
+)
+
+func InitOCIWorker() {
+	Register(&OCI{ID: "oci"})
+
+	// the rootless uid is defined in Dockerfile
+	if s := os.Getenv("BUILDKIT_INTEGRATION_ROOTLESS_IDPAIR"); s != "" {
+		var uid, gid int
+		if _, err := fmt.Sscanf(s, "%d:%d", &uid, &gid); err != nil {
+			bklog.L.Fatalf("unexpected BUILDKIT_INTEGRATION_ROOTLESS_IDPAIR: %q", s)
+		}
+		if rootlessSupported(uid) {
+			Register(&OCI{ID: "oci-rootless", UID: uid, GID: gid})
+		}
+	}
+
+	if s := os.Getenv("BUILDKIT_INTEGRATION_SNAPSHOTTER"); s != "" {
+		Register(&OCI{ID: "oci-snapshotter-" + s, Snapshotter: s})
+	}
+}
+
+type OCI struct {
+	ID          string
+	UID         int
+	GID         int
+	Snapshotter string
+}
+
+func (s *OCI) Name() string {
+	return s.ID
+}
+
+func (s *OCI) Rootless() bool {
+	return s.UID != 0
+}
+
+func (s *OCI) New(ctx context.Context, cfg *BackendConfig) (Backend, func() error, error) {
+	if err := lookupBinary("buildkitd"); err != nil {
+		return nil, nil, err
+	}
+	if err := requireRoot(); err != nil {
+		return nil, nil, err
+	}
+	// Include use of --oci-worker-labels to trigger https://github.com/moby/buildkit/pull/603
+	buildkitdArgs := []string{"buildkitd", "--oci-worker=true", "--containerd-worker=false", "--oci-worker-gc=false", "--oci-worker-labels=org.mobyproject.buildkit.worker.sandbox=true"}
+
+	if s.Snapshotter != "" {
+		buildkitdArgs = append(buildkitdArgs,
+			fmt.Sprintf("--oci-worker-snapshotter=%s", s.Snapshotter))
+	}
+
+	if s.UID != 0 {
+		if s.GID == 0 {
+			return nil, nil, errors.Errorf("unsupported id pair: uid=%d, gid=%d", s.UID, s.GID)
+		}
+		// TODO: make sure the user exists and subuid/subgid are configured.
+		buildkitdArgs = append([]string{"sudo", "-u", fmt.Sprintf("#%d", s.UID), "-i", "--", "exec", "rootlesskit"}, buildkitdArgs...)
+	}
+
+	var extraEnv []string
+	if runtime.GOOS != "windows" && s.Snapshotter != "native" {
+		extraEnv = append(extraEnv, "BUILDKIT_DEBUG_FORCE_OVERLAY_DIFF=true")
+	}
+	buildkitdSock, stop, err := runBuildkitd(ctx, cfg, buildkitdArgs, cfg.Logs, s.UID, s.GID, extraEnv)
+	if err != nil {
+		printLogs(cfg.Logs, log.Println)
+		return nil, nil, err
+	}
+
+	return backend{
+		address:     buildkitdSock,
+		rootless:    s.UID != 0,
+		snapshotter: s.Snapshotter,
+	}, stop, nil
+}