driver: resolve BuildKit version for docker driver

Buildx currently returns the Docker Engine version for the docker driver
and it can be confusing. This is because BuildKit before 0.11 version does
not support the Info API that returns the BuildKit version.

This change resolves the BuildKit version from the Docker engine one.

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

driver/docker/version_test.go

@@ -0,0 +1,127 @@
+package docker
+
+import (
+	"testing"
+
+	"github.com/Masterminds/semver/v3"
+	"github.com/stretchr/testify/require"
+)
+
+func TestConstraint(t *testing.T) {
+	for _, tt := range mobyBuildkitVersions {
+		tt := tt
+		t.Run(tt.MobyVersionConstraint, func(t *testing.T) {
+			_, err := semver.NewConstraint(tt.MobyVersionConstraint)
+			require.NoError(t, err)
+		})
+	}
+}
+
+func TestResolveBuildKitVersion(t *testing.T) {
+	cases := []struct {
+		mobyVersion string
+		expected    string
+		err         bool
+	}{
+		{
+			mobyVersion: "18.06.1-ce",
+			expected:    "v0.0.0+98f1604",
+		},
+		{
+			mobyVersion: "18.09.1-beta1",
+			expected:    "v0.3.3",
+		},
+		{
+			mobyVersion: "19.03.0-beta1",
+			expected:    "v0.4.0+b302896",
+		},
+		{
+			mobyVersion: "19.03.5-beta2",
+			expected:    "v0.6.2+ff93519",
+		},
+		{
+			mobyVersion: "19.03.13-beta1",
+			expected:    "v0.6.4+da1f4bf",
+		},
+		{
+			mobyVersion: "19.03.13-beta2",
+			expected:    "v0.6.4+da1f4bf",
+		},
+		{
+			mobyVersion: "19.03.13",
+			expected:    "v0.6.4+df89d4d",
+		},
+		{
+			mobyVersion: "20.10.3-rc.1",
+			expected:    "v0.8.1+68bb095",
+		},
+		{
+			mobyVersion: "20.10.3",
+			expected:    "v0.8.1+68bb095",
+		},
+		{
+			mobyVersion: "20.10.4",
+			expected:    "v0.8.2",
+		},
+		{
+			mobyVersion: "20.10.16",
+			expected:    "v0.8.2+bc07b2b8",
+		},
+		{
+			mobyVersion: "20.10.19",
+			expected:    "v0.8.2+3a1eeca5",
+		},
+		{
+			mobyVersion: "20.10.23",
+			expected:    "v0.8.2+eeb7b65",
+		},
+		{
+			mobyVersion: "20.10.24",
+			expected:    "v0.8+unknown",
+		},
+		{
+			mobyVersion: "20.10.50",
+			expected:    "v0.8+unknown",
+		},
+		{
+			mobyVersion: "22.06.0-beta.0",
+			expected:    "v0.10.3",
+		},
+		{
+			mobyVersion: "22.06.0",
+			expected:    "v0.10.3",
+		},
+		{
+			mobyVersion: "23.0.0-rc.4",
+			expected:    "v0.10.6",
+		},
+		{
+			mobyVersion: "23.0.0",
+			expected:    "v0.10.6",
+		},
+		{
+			mobyVersion: "23.0.1",
+			expected:    "v0.10.6+4f0ee09",
+		},
+		{
+			mobyVersion: "23.0.2-rc.1",
+			expected:    "v0.10+unknown",
+		},
+		{
+			mobyVersion: "23.0.4",
+			expected:    "v0.10+unknown",
+		},
+	}
+	for _, tt := range cases {
+		tt := tt
+		t.Run(tt.mobyVersion, func(t *testing.T) {
+			bkVersion, err := resolveBuildKitVersion(tt.mobyVersion)
+			if tt.err {
+				require.Error(t, err)
+				return
+			}
+			require.NoError(t, err)
+			require.Equal(t, tt.expected, bkVersion)
+		})
+	}
+}