Docker容器ID的生成方式 [英] How the docker container id is generated
本文介绍了Docker容器ID的生成方式的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我想知道容器ID的生成方式,所以请提供执行docker run时提供容器ID的源代码?
I wanted to know how the container id is generated so please provide the source code that provides the container id when the docker run is executed?
推荐答案
这是docker守护程序用于创建容器的功能的代码段:
Here is a code snippet from docker daemon's function for creating Containers:
func (daemon *Daemon) newContainer(name string, config *runconfig.Config, imgID string) (*Container, error) {
var (
id string
err error
)
id, name, err = daemon.generateIDAndName(name)
if err != nil {
return nil, err
}
…
base := daemon.newBaseContainer(id)
…
base.ExecDriver = daemon.execDriver.Name()
return &base, err
}
因此,创建ID和名称的逻辑是在generateIDAndName函数中:
So, the logic of creating ID and Name is in generateIDAndName function:
func (daemon *Daemon) generateIDAndName(name string) (string, string, error) {
var (
err error
id = stringid.GenerateNonCryptoID()
)
if name == "" {
if name, err = daemon.generateNewName(id); err != nil {
return "", "", err
}
return id, name, nil
}
if name, err = daemon.reserveName(id, name); err != nil {
return "", "", err
}
return id, name, nil
}
这里是字符串ID来源,具体的方法是使用false作为输入参数的generateID:
Here is stringid sources and the concrete method is generateID with false as input parameter:
func generateID(crypto bool) string {
b := make([]byte, 32)
var r io.Reader = random.Reader
if crypto {
r = rand.Reader
}
for {
if _, err := io.ReadFull(r, b); err != nil {
panic(err) // This shouldn't happen
}
id := hex.EncodeToString(b)
// if we try to parse the truncated for as an int and we don't have
// an error then the value is all numberic and causes issues when
// used as a hostname. ref #3869
if _, err := strconv.ParseInt(TruncateID(id), 10, 64); err == nil {
continue
}
return id
}
}
如您所见,该值是使用随机
As you can see, the value is randomly generated with this random
// Reader is a global, shared instance of a pseudorandom bytes generator.
// It doesn't consume entropy.
var Reader io.Reader = &reader{rnd: Rand}
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