// LoadContainer loads a Container Runtime Manifest (as prepared by stage0) and
// its associated Application Manifests, under $root/stage1/opt/stage1/$apphash
func LoadContainer(root string) (*Container, error) {
c := &Container{
Root: root,
Apps: make(map[string]*schema.AppManifest),
}
buf, err := ioutil.ReadFile(rktpath.ContainerManifestPath(c.Root))
if err != nil {
return nil, fmt.Errorf("failed reading container runtime manifest: %v", err)
}
cm := &schema.ContainerRuntimeManifest{}
if err := json.Unmarshal(buf, cm); err != nil {
return nil, fmt.Errorf("failed unmarshalling container runtime manifest: %v", err)
}
c.Manifest = cm
for _, app := range c.Manifest.Apps {
ampath := rktpath.AppManifestPath(c.Root, app.ImageID)
buf, err := ioutil.ReadFile(ampath)
if err != nil {
return nil, fmt.Errorf("failed reading app manifest %q: %v", ampath, err)
}
am := &schema.AppManifest{}
if err = json.Unmarshal(buf, am); err != nil {
return nil, fmt.Errorf("failed unmarshalling app manifest %q: %v", ampath, err)
}
name := am.Name.String()
if _, ok := c.Apps[name]; ok {
return nil, fmt.Errorf("got multiple definitions for app: %s", name)
}
c.Apps[name] = am
}
return c, nil
}
// Setup sets up a filesystem for a container based on the given config.
// The directory containing the filesystem is returned, and any error encountered.
func Setup(cfg Config) (string, error) {
if cfg.Debug {
log.SetOutput(os.Stderr)
}
cuuid, err := types.NewUUID(uuid.New())
if err != nil {
return "", fmt.Errorf("error creating UID: %v", err)
}
// TODO(jonboulle): collision detection/mitigation
// Create a directory for this container
dir := filepath.Join(cfg.ContainersDir, cuuid.String())
if err := os.MkdirAll(dir, 0700); err != nil {
return "", fmt.Errorf("error creating directory: %v", err)
}
log.Printf("Unpacking stage1 rootfs")
if cfg.Stage1Rootfs != "" {
err = unpackRootfs(cfg.Stage1Rootfs, rktpath.Stage1RootfsPath(dir))
} else {
err = unpackBuiltinRootfs(rktpath.Stage1RootfsPath(dir))
}
if err != nil {
return "", fmt.Errorf("error unpacking rootfs: %v", err)
}
log.Printf("Writing stage1 init")
var in io.Reader
if cfg.Stage1Init != "" {
in, err = os.Open(cfg.Stage1Init)
if err != nil {
return "", fmt.Errorf("error loading stage1 init binary: %v", err)
}
} else {
init_bin, err := stage1_init.Asset("s1init")
if err != nil {
return "", fmt.Errorf("error accessing stage1 init bindata: %v", err)
}
in = bytes.NewBuffer(init_bin)
}
fn := filepath.Join(dir, initPath)
out, err := os.OpenFile(fn, os.O_CREATE|os.O_WRONLY, 0555)
if err != nil {
return "", fmt.Errorf("error opening stage1 init for writing: %v", err)
}
if _, err := io.Copy(out, in); err != nil {
return "", fmt.Errorf("error writing stage1 init: %v", err)
}
if err := out.Close(); err != nil {
return "", fmt.Errorf("error closing stage1 init: %v", err)
}
log.Printf("Wrote filesystem to %s\n", dir)
cm := schema.ContainerRuntimeManifest{
ACKind: "ContainerRuntimeManifest",
UUID: *cuuid,
Apps: make(schema.AppList, 0),
}
v, err := types.NewSemVer(version.Version)
if err != nil {
return "", fmt.Errorf("error creating version: %v", err)
}
cm.ACVersion = *v
for _, img := range cfg.Images {
am, err := setupImage(cfg, img, dir)
if err != nil {
return "", fmt.Errorf("error setting up image %s: %v", img, err)
}
if cm.Apps.Get(am.Name) != nil {
return "", fmt.Errorf("error: multiple apps with name %s", am.Name)
}
a := schema.App{
Name: am.Name,
ImageID: img,
Isolators: am.Isolators,
Annotations: am.Annotations,
}
cm.Apps = append(cm.Apps, a)
}
var sVols []types.Volume
for key, path := range cfg.Volumes {
v := types.Volume{
Kind: "host",
Source: path,
ReadOnly: true,
Fulfills: []types.ACName{
types.ACName(key),
},
}
sVols = append(sVols, v)
}
// TODO(jonboulle): check that app mountpoint expectations are
// satisfied here, rather than waiting for stage1
cm.Volumes = sVols
cdoc, err := json.Marshal(cm)
if err != nil {
return "", fmt.Errorf("error marshalling container manifest: %v", err)
}
log.Printf("Writing container manifest")
fn = rktpath.ContainerManifestPath(dir)
if err := ioutil.WriteFile(fn, cdoc, 0700); err != nil {
return "", fmt.Errorf("error writing container manifest: %v", err)
}
return dir, nil
}