// New initializes a new engine managing the directory specified at `root`.
// `root` is used to store containers and any other state private to the engine.
// Changing the contents of the root without executing a job will cause unspecified
// behavior.
func New(root string) (*Engine, error) {
// Check for unsupported architectures
if runtime.GOARCH != "amd64" && runtime.GOARCH != "386" {
return nil, fmt.Errorf("The docker runtime currently only supports amd64 and 386 (not %s). This will change in the future. Aborting.", runtime.GOARCH)
}
// Check for unsupported kernel versions
// FIXME: it would be cleaner to not test for specific versions, but rather
// test for specific functionalities.
// Unfortunately we can't test for the feature "does not cause a kernel panic"
// without actually causing a kernel panic, so we need this workaround until
// the circumstances of pre-3.8 crashes are clearer.
// For details see http://github.com/Nerdness/docker/issues/407
if k, err := utils.GetKernelVersion(); err != nil {
log.Printf("WARNING: %s\n", err)
} else {
if utils.CompareKernelVersion(k, &utils.KernelVersionInfo{Kernel: 3, Major: 8, Minor: 0}) < 0 {
if os.Getenv("DOCKER_NOWARN_KERNEL_VERSION") == "" {
log.Printf("WARNING: You are running linux kernel version %s, which might be unstable running docker. Please upgrade your kernel to 3.8.0.", k.String())
}
}
}
if err := os.MkdirAll(root, 0700); err != nil && !os.IsExist(err) {
return nil, err
}
// Docker makes some assumptions about the "absoluteness" of root
// ... so let's make sure it has no symlinks
if p, err := filepath.Abs(root); err != nil {
log.Fatalf("Unable to get absolute root (%s): %s", root, err)
} else {
root = p
}
if p, err := filepath.EvalSymlinks(root); err != nil {
log.Fatalf("Unable to canonicalize root (%s): %s", root, err)
} else {
root = p
}
eng := &Engine{
root: root,
handlers: make(map[string]Handler),
id: utils.RandomString(),
Stdout: os.Stdout,
Stderr: os.Stderr,
Stdin: os.Stdin,
}
// Copy existing global handlers
for k, v := range globalHandlers {
eng.handlers[k] = v
}
return eng, nil
}
// dockerVersion returns detailed version information in the form of a queriable
// environment.
func dockerVersion() *engine.Env {
v := &engine.Env{}
v.Set("Version", VERSION)
v.Set("GitCommit", GITCOMMIT)
v.Set("GoVersion", runtime.Version())
v.Set("Os", runtime.GOOS)
v.Set("Arch", runtime.GOARCH)
// FIXME:utils.GetKernelVersion should only be needed here
if kernelVersion, err := utils.GetKernelVersion(); err == nil {
v.Set("KernelVersion", kernelVersion.String())
}
return v
}