diff options
Diffstat (limited to 'users/fcuny/exp/containerd-to-vm/cmd/c2vm')
| -rw-r--r-- | users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go | 305 |
1 files changed, 0 insertions, 305 deletions
diff --git a/users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go b/users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go deleted file mode 100644 index 320bc91..0000000 --- a/users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go +++ /dev/null @@ -1,305 +0,0 @@ -package main - -import ( - "bufio" - "context" - "encoding/json" - "flag" - "fmt" - "io/ioutil" - "log" - "os" - "os/exec" - "path/filepath" - "strings" - - "github.com/containerd/containerd" - "github.com/containerd/containerd/content" - "github.com/containerd/containerd/images" - "github.com/containerd/containerd/namespaces" - "github.com/containerd/containerd/platforms" - "github.com/docker/docker/pkg/archive" - "github.com/firecracker-microvm/firecracker-go-sdk" - "github.com/firecracker-microvm/firecracker-go-sdk/client/models" - "github.com/google/renameio" - ocispec "github.com/opencontainers/image-spec/specs-go/v1" -) - -const ( - containerdSock = "/run/containerd/containerd.sock" - defaultNamespace = "c2vm" -) - -var ( - firecrackerSock = filepath.Join(os.Getenv("XDG_RUNTIME_DIR"), "firecracker.sock") - platform = platforms.Only(ocispec.Platform{ - OS: "linux", - Architecture: "amd64", - }) -) - -func main() { - var ( - containerName = flag.String("container", "", "Name of the container") - outFile = flag.String("out", "container.img", "Path to store the image") - kernel = flag.String("kernel", "", "Path to the linux kernel image") - firecrackerBinary = flag.String("firecracker-binary", "", "Path to the firecracker binary") - metricsFifo = flag.String("metrics-fifo", "", "FIFO to the firecracker metrics") - ) - - flag.Parse() - - if *containerName == "" { - log.Fatal("a container is required") - } - - if *kernel == "" { - log.Fatalf("a linux kernel is required") - } - - if *firecrackerBinary == "" { - log.Fatalf("the path to the firecracker binary is required") - } - - client, err := containerd.New(containerdSock) - if err != nil { - log.Fatalf("failed to create a client for containerd: %v", err) - } - defer client.Close() - - ctx := namespaces.WithNamespace(context.Background(), defaultNamespace) - ctx, done, err := client.WithLease(ctx) - if err != nil { - log.Fatalf("failed to get a lease: %v", err) - } - defer done(ctx) - - image, err := client.Pull(ctx, *containerName, containerd.WithPlatformMatcher(platform)) - if err != nil { - log.Fatalf("failed to pull the container %s: %v\n", *containerName, err) - } - - imageSize, err := image.Usage(ctx, containerd.WithUsageManifestLimit(1)) - if err != nil { - log.Fatalf("failed to get the size of the image: %v", err) - } - - log.Printf("pulled %s (%d bytes)\n", image.Name(), imageSize) - - mntDir, err := ioutil.TempDir("", "c2vm") - if err != nil { - log.Fatalf("Failed to create mount temp dir: %v\n", err) - } - - if err := createLoopDevice(*outFile, mntDir); err != nil { - log.Fatalf("%v\n", err) - } - - if err := extract(ctx, client, image, mntDir); err != nil { - log.Fatalf("failed to extract the container: %v\n", err) - } - - if err = initScript(ctx, client, image, mntDir); err != nil { - log.Fatalf("failed to create init script: %s\n", err) - } - - if err = extraFiles(mntDir); err != nil { - log.Fatalf("failed to add extra files to the image: %v\n", err) - } - - if err := detachLoopDevice(mntDir); err != nil { - log.Fatalf("failed to umount %s: %v\n", mntDir, err) - } - - if err := resizeImage(*outFile); err != nil { - log.Fatalf("failed to resize the image %s: %s\n", *outFile, err) - } - - bootVM(ctx, *outFile, *kernel, *firecrackerBinary, *metricsFifo) -} - -func extract(ctx context.Context, client *containerd.Client, image containerd.Image, mntDir string) error { - manifest, err := images.Manifest(ctx, client.ContentStore(), image.Target(), platform) - if err != nil { - log.Fatalf("failed to get the manifest: %v\n", err) - } - - for _, desc := range manifest.Layers { - log.Printf("extracting layer %s\n", desc.Digest.String()) - layer, err := client.ContentStore().ReaderAt(ctx, desc) - if err != nil { - return err - } - if err := archive.Untar(content.NewReader(layer), mntDir, &archive.TarOptions{NoLchown: true}); err != nil { - return err - } - } - - return nil -} - -func createLoopDevice(rawFile, mntDir string) error { - f, err := renameio.TempFile("", rawFile) - if err != nil { - return err - } - defer f.Cleanup() - - command := exec.Command("fallocate", "-l", "2G", f.Name()) - if err := command.Run(); err != nil { - return fmt.Errorf("fallocate error: %s", err) - } - - command = exec.Command("mkfs.ext4", "-F", f.Name()) - if err := command.Run(); err != nil { - return fmt.Errorf("mkfs.ext4 error: %s", err) - } - - f.CloseAtomicallyReplace() - - command = exec.Command("mount", "-o", "loop", rawFile, mntDir) - if err := command.Run(); err != nil { - return fmt.Errorf("mount error: %s", err) - } - log.Printf("mounted %s on %s\n", rawFile, mntDir) - return nil -} - -func detachLoopDevice(mntDir string) error { - log.Printf("umount %s\n", mntDir) - command := exec.Command("umount", mntDir) - return command.Run() -} - -func resizeImage(rawFile string) error { - // let's bring the image to a more reasonable size. We do this by - // first running e2fsck on the image then we can resize the image. - command := exec.Command("/usr/bin/e2fsck", "-p", "-f", rawFile) - if err := command.Run(); err != nil { - return fmt.Errorf("e2fsck error: %s", err) - } - - command = exec.Command("resize2fs", "-M", rawFile) - if err := command.Run(); err != nil { - return fmt.Errorf("resize2fs error: %s", err) - } - return nil -} - -func extraFiles(mntDir string) error { - if err := writeToFile(filepath.Join(mntDir, "etc", "hosts"), "127.0.0.1\tlocalhost\n"); err != nil { - return err - } - if err := writeToFile(filepath.Join(mntDir, "etc", "resolv.conf"), "nameserver 192.168.0.1\n"); err != nil { - return err - } - return nil -} - -func initScript(ctx context.Context, client *containerd.Client, image containerd.Image, mntDir string) error { - config, err := images.Config(ctx, client.ContentStore(), image.Target(), platform) - if err != nil { - return err - } - - configBlob, err := content.ReadBlob(ctx, client.ContentStore(), config) - if err != nil { - return err - } - var imageSpec ocispec.Image - json.Unmarshal(configBlob, &imageSpec) - initCmd := strings.Join(imageSpec.Config.Cmd, " ") - initEnvs := imageSpec.Config.Env - - initPath := filepath.Join(mntDir, "init.sh") - f, err := renameio.TempFile("", initPath) - if err != nil { - return err - } - defer f.Cleanup() - - writer := bufio.NewWriter(f) - fmt.Fprintf(writer, "#!/bin/sh\n") - for _, env := range initEnvs { - fmt.Fprintf(writer, "export %s\n", env) - } - fmt.Fprintf(writer, "%s\n", initCmd) - writer.Flush() - - f.CloseAtomicallyReplace() - - mode := int(0755) - os.Chmod(initPath, os.FileMode(mode)) - log.Printf("init script created") - return nil -} - -func writeToFile(filepath string, content string) error { - if err := ioutil.WriteFile(filepath, []byte(content), 0644); err != nil { - return fmt.Errorf("writeToFile %s: %v", filepath, err) - } - return nil -} - -func bootVM(ctx context.Context, rawImage, kernel, firecrackerBinary, metricsFifo string) { - vmmCtx, vmmCancel := context.WithCancel(ctx) - defer vmmCancel() - - devices := make([]models.Drive, 1) - devices[0] = models.Drive{ - DriveID: firecracker.String("1"), - PathOnHost: &rawImage, - IsRootDevice: firecracker.Bool(true), - IsReadOnly: firecracker.Bool(false), - } - fcCfg := firecracker.Config{ - LogLevel: "debug", - SocketPath: firecrackerSock, - KernelImagePath: kernel, - KernelArgs: "console=ttyS0 reboot=k panic=1 acpi=off pci=off i8042.noaux i8042.nomux i8042.nopnp i8042.dumbkbd init=/init.sh random.trust_cpu=on", - Drives: devices, - MetricsFifo: metricsFifo, - MachineCfg: models.MachineConfiguration{ - VcpuCount: firecracker.Int64(1), - CPUTemplate: models.CPUTemplate("C3"), - HtEnabled: firecracker.Bool(true), - MemSizeMib: firecracker.Int64(512), - }, - NetworkInterfaces: []firecracker.NetworkInterface{ - { - CNIConfiguration: &firecracker.CNIConfiguration{ - NetworkName: "c2vm", - IfName: "eth0", - }, - }, - }, - } - - machineOpts := []firecracker.Opt{} - - command := firecracker.VMCommandBuilder{}. - WithBin(firecrackerBinary). - WithSocketPath(fcCfg.SocketPath). - WithStdin(os.Stdin). - WithStdout(os.Stdout). - WithStderr(os.Stderr). - Build(ctx) - machineOpts = append(machineOpts, firecracker.WithProcessRunner(command)) - m, err := firecracker.NewMachine(vmmCtx, fcCfg, machineOpts...) - if err != nil { - fmt.Printf("failed to start the vm: %+v\n", err) - os.Exit(1) - } - - if err := m.Start(vmmCtx); err != nil { - fmt.Printf("failed to start the vm: %+v\n", err) - os.Exit(1) - } - defer m.StopVMM() - - if err := m.Wait(vmmCtx); err != nil { - fmt.Printf("failed to start the vm: %+v\n", err) - os.Exit(1) - } - log.Print("Machine was started") -} |