podman buildx inspect support

Added support for "podman buildx inspect". The goal was to replicate the default output from "docker buildx inspect" as
much as possible but a problem encountered was podman not supporting BuildKit. To replicate the output I resorted to
printing the statements with default values but only changed the driver name to use podman instead of docker. Since
there was no buildkit, gave it the value of "N/A" to depict it's not supported. For Platforms, I resorted to using
the emulated architectures found on your linux system + the host architecture of your local machine or podman server. The
bootstrap flag was also added but is considered a NOP since there is no buildkit container to run before running inspect.
An extra field was added to the HostInfo struct so when you run "podman info" the emulated architectures will show, this
was used so you can grab the information from the podman engine.

Fixes #13014

Signed-off-by: Joshua Arrevillaga <[email protected]>

Author: 2004joshua

cmd/podman/images/buildx_inspect.go

@@ -0,0 +1,87 @@
+package images
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/containers/podman/v5/cmd/podman/registry"
+	"github.com/spf13/cobra"
+)
+
+type buildNode struct {
+	Name            string
+	Endpoint        string
+	Status          string
+	BuildkitVersion string
+	Platforms       []string
+}
+
+type buildxInspectOutput struct {
+	builderName string
+	driverName  string
+	Nodes       []buildNode
+}
+
+var buildxInspectCmd = &cobra.Command{
+	Use:   "inspect",
+	Short: "Inspects the current buildx builder instance",
+	Long:  "Displays information about the current builder instance (compatibility with Docker buildx inspect)",
+	RunE:  runBuildxInspect,
+	Example: `podman buildx inspect
+	podman buildx inspect --bootstrap`,
+}
+
+func init() {
+	buildxInspectCmd.Flags().Bool("bootstrap", false, "Currently a No Op for podman")
+	registry.Commands = append(registry.Commands, registry.CliCommand{
+		Command: buildxInspectCmd,
+		Parent:  buildxCmd,
+	})
+}
+
+func runBuildxInspect(cmd *cobra.Command, args []string) error {
+	// Constants are based on default values for Docker buildx inspect.
+	defaultNode := buildNode{
+		Name:            "default",
+		Endpoint:        "default",
+		Status:          "running",
+		BuildkitVersion: "N/A",
+		Platforms:       []string{"unknown/unknown"},
+	}
+
+	info, err := registry.ContainerEngine().Info(registry.Context())
+
+	if err != nil {
+		return fmt.Errorf("retrieving podman information: %w", err)
+	}
+
+	if registry.IsRemote() {
+		runtimeOS := info.Host.OS
+		runtimeArch := info.Host.Arch
+		defaultNode.Platforms = []string{fmt.Sprintf("%s/%s", runtimeOS, runtimeArch)}
+	} else {
+		platforms := info.Host.EmulatedArchitectures
+		platforms = append(platforms, fmt.Sprintf("%s/%s", info.Host.OS, info.Host.Arch))
+		defaultNode.Platforms = platforms
+	}
+
+	out := buildxInspectOutput{
+		builderName: "default",
+		driverName:  "podman",
+		Nodes:       []buildNode{defaultNode},
+	}
+
+	fmt.Printf("Name:   %s\n", out.builderName)
+	fmt.Printf("Driver: %s\n", out.driverName)
+	fmt.Println()
+
+	fmt.Println("Nodes:")
+	fmt.Printf("Name:             %s\n", out.Nodes[0].Name)
+	fmt.Printf("Endpoint:         %s\n", out.Nodes[0].Endpoint)
+	fmt.Printf("Status:           %s\n", out.Nodes[0].Status)
+	fmt.Printf("Buildkit version: %s\n", out.Nodes[0].BuildkitVersion)
+
+	fmt.Printf("Platforms:        %s\n", strings.Join(out.Nodes[0].Platforms, ", "))
+	fmt.Println("Labels: ")
+	return nil
+}

libpod/define/info.go

@@ -66,6 +66,8 @@ type HostInfo struct {
 	Uptime    string `json:"uptime"`
 	Variant   string `json:"variant"`
 	Linkmode  string `json:"linkmode"`
+
+	EmulatedArchitectures []string `json:"emulatedArchitectures,omitempty"`
 }
 
 // RemoteSocket describes information about the API socket

pkg/domain/infra/abi/system.go

@@ -15,6 +15,7 @@ import (
 	"github.com/containers/podman/v5/libpod/define"
 	"github.com/containers/podman/v5/pkg/domain/entities"
 	"github.com/containers/podman/v5/pkg/domain/entities/reports"
+	"github.com/containers/podman/v5/pkg/emulation"
 	"github.com/containers/podman/v5/pkg/util"
 	"github.com/containers/storage"
 	"github.com/containers/storage/pkg/directory"
@@ -27,6 +28,9 @@ func (ic *ContainerEngine) Info(ctx context.Context) (*define.Info, error) {
 	if err != nil {
 		return nil, err
 	}
+
+	info.Host.EmulatedArchitectures = emulation.Registered()
+
 	info.Host.RemoteSocket = &define.RemoteSocket{Path: ic.Libpod.RemoteURI()}
 
 	// `podman system connection add` invokes podman via ssh to fill in connection string. Here

test/e2e/buildx_inspect_test.go

@@ -0,0 +1,61 @@
+//go:build linux || freebsd
+
+package integration
+
+import (
+	"encoding/json"
+	"regexp"
+	"strings"
+
+	. "github.com/onsi/ginkgo/v2"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Podman buildx inspect", func() {
+	It("podman buildx inspect", func() {
+		SkipIfRemote("binfmt-misc emulation only probed in local mode")
+
+		session := podmanTest.PodmanExitCleanly("buildx", "inspect")
+		out := session.OutputToString()
+
+		session_bootstrap := podmanTest.PodmanExitCleanly("buildx", "inspect", "--bootstrap")
+		out_bootstrap := session_bootstrap.OutputToString()
+		Expect(out_bootstrap).To(Equal(out), "Output of 'podman buildx inspect' and 'podman buildx inspect --bootstrap' should be the same")
+
+		emuInfo := podmanTest.PodmanExitCleanly("info", "--format", "{{json .Host.EmulatedArchitectures}}")
+		var emuArchs []string
+		Expect(json.Unmarshal([]byte(emuInfo.OutputToString()), &emuArchs)).To(Succeed())
+
+		nativeInfo := podmanTest.PodmanExitCleanly("info", "--format", "{{.Host.OS}}/{{.Host.Arch}}")
+		nativePlat := strings.TrimSpace(nativeInfo.OutputToString())
+		Expect(nativePlat).ToNot(BeEmpty())
+
+		expected := append(emuArchs, nativePlat)
+
+		for _, p := range expected {
+			re := regexp.MustCompile(`(?s)Platforms:.*\b` + regexp.QuoteMeta(p) + `\b`)
+			Expect(out).To(MatchRegexp(re.String()), "missing %q in:\n%s", p, out)
+		}
+	})
+
+	It("podman-remote buildx inspect", func() {
+		session := podmanTest.PodmanExitCleanly("buildx", "inspect")
+		out := session.OutputToString()
+
+		session_bootstrap := podmanTest.PodmanExitCleanly("buildx", "inspect", "--bootstrap")
+		out_bootstrap := session_bootstrap.OutputToString()
+		Expect(out_bootstrap).To(Equal(out), "Output of 'podman-remote buildx inspect' and 'podman-remote buildx inspect --bootstrap' should be the same")
+
+		emuInfo := podmanTest.PodmanExitCleanly("info", "--format", "{{json .Host.EmulatedArchitectures}}")
+		var emuArchs []string
+		Expect(json.Unmarshal([]byte(emuInfo.OutputToString()), &emuArchs)).To(Succeed())
+		Expect(emuArchs).To(BeEmpty())
+
+		nativeInfo := podmanTest.PodmanExitCleanly("info", "--format", "{{.Host.OS}}/{{.Host.Arch}}")
+		nativePlatform := strings.TrimSpace(nativeInfo.OutputToString())
+		Expect(nativePlatform).ToNot(BeEmpty())
+
+		re := regexp.MustCompile(`(?s)Platforms:.*\b` + regexp.QuoteMeta(nativePlatform) + `\b`)
+		Expect(out).To(MatchRegexp(re.String()), "missing native %q in:\n%s", nativePlatform, out)
+	})
+})