Display buildkit version in nerdctl

Fixes#1082

Signed-off-by: Manu Gupta <manugupt1@gmail.com>

cmd/nerdctl/version.go

@@ -86,6 +86,7 @@ func versionAction(cmd *cobra.Command, args []string) error {
 			}
 		}
 	}
+	fmt.Fprintf(w, "\n")
 	return vErr
 }
 

pkg/infoutil/infoutil.go

@@ -20,10 +20,14 @@ import (
 	"context"
 	"fmt"
 	"os"
+	"os/exec"
 	"runtime"
 	"strings"
 	"time"
 
+	"github.com/containerd/nerdctl/pkg/buildkitutil"
+	"github.com/sirupsen/logrus"
+
 	"github.com/Masterminds/semver/v3"
 	"github.com/containerd/containerd"
 	ptypes "github.com/containerd/containerd/protobuf/types"
@@ -133,8 +137,9 @@ func ServerVersion(ctx context.Context, client *containerd.Client) (*dockercompa
 				Version: daemonVersion.Version,
 				Details: map[string]string{"GitCommit": daemonVersion.Revision},
 			},
+			getBuildKitVersion(),
+			getRuncVersion(),
 		},
-		// TODO: add runc version
 	}
 	return v, nil
 }
@@ -150,3 +155,46 @@ func ServerSemVer(ctx context.Context, client *containerd.Client) (*semver.Versi
 	}
 	return sv, nil
 }
+
+func getBuildKitVersion() dockercompat.ComponentVersion {
+	buildctlBinary, err := buildkitutil.BuildctlBinary()
+	if err != nil {
+		logrus.Warnf("unable to determine buildkit version: %s", err.Error())
+		return dockercompat.ComponentVersion{Name: "buildkit"}
+	}
+
+	stdout, err := exec.Command(buildctlBinary, "--version").Output()
+	if err != nil {
+		logrus.Warnf("unable to determine buildkit version: %s", err.Error())
+		return dockercompat.ComponentVersion{Name: "buildkit"}
+	}
+
+	versionStr := strings.Fields(strings.TrimSpace(string(stdout)))
+
+	return dockercompat.ComponentVersion{
+		Name:    "buildkit",
+		Version: versionStr[2],
+		Details: map[string]string{"GitCommit": versionStr[3]},
+	}
+}
+
+func getRuncVersion() dockercompat.ComponentVersion {
+	stdout, err := exec.Command("runc", "--version").Output()
+	if err != nil {
+		logrus.Warnf("unable to determine runc version: %s", err.Error())
+		return dockercompat.ComponentVersion{Name: "runc"}
+	}
+
+	var versionList = strings.Split(string(stdout), "\n")
+
+	return dockercompat.ComponentVersion{
+		Name:    "runc",
+		Version: strings.Fields(versionList[0])[2],
+		Details: map[string]string{
+			"GitCommit":  strings.Fields(versionList[1])[1],
+			"spec":       strings.Fields(versionList[2])[1],
+			"go":         strings.Fields(versionList[3])[1],
+			"libseccomp": strings.Fields(versionList[4])[1],
+		},
+	}
+}