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authorFranck Cuny <franck@fcuny.net>2022-10-05 17:59:37 -0700
committerFranck Cuny <franck@fcuny.net>2022-10-05 17:59:37 -0700
commit35d131a030b772f5f43be6165cbcce319cdb236b (patch)
tree609456537d89ab8b3b0083ba3320125148d6aaa4 /users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go
parentref(fcuny/notes): delete notes (diff)
downloadinfra-35d131a030b772f5f43be6165cbcce319cdb236b.tar.gz
ref(fcuny/exp): delete containerd-to-vm
The code is in https://github.com/fcuny/containerd-to-vm
Diffstat (limited to '')
-rw-r--r--users/fcuny/exp/containerd-to-vm/cmd/c2vm/main.go305
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")
-}