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Date: 一月 11, 2016

Mesos笔记 (9)—— Containerizer类代码解析

Containerizer类(定义在src/slave/containerizer/containerizer.hpp )是所有Containerizer的抽象父类。除了默认的构造函数和一个什么都没做的析构函数,其只实现了createresources方法。create方法代码如下(v0.26版本):

Try<Containerizer*> Containerizer::create(
    const Flags& flags,
    bool local,
    Fetcher* fetcher)
{
  if (flags.isolation == "external") {
    LOG(WARNING) << "The 'external' isolation flag is deprecated, "
                 << "please update your flags to"
                 << " '--containerizers=external'.";

    Try<ExternalContainerizer*> containerizer =
      ExternalContainerizer::create(flags);
    if (containerizer.isError()) {
      return Error("Could not create ExternalContainerizer: " +
                   containerizer.error());
    }

    return containerizer.get();
  }

  // TODO(benh): We need to store which containerizer or
  // containerizers were being used. See MESOS-1663.

  // Create containerizer(s).
  vector<Containerizer*> containerizers;

  foreach (const string& type, strings::split(flags.containerizers, ",")) {
    if (type == "mesos") {
      Try<MesosContainerizer*> containerizer =
        MesosContainerizer::create(flags, local, fetcher);
      if (containerizer.isError()) {
        return Error("Could not create MesosContainerizer: " +
                     containerizer.error());
      } else {
        containerizers.push_back(containerizer.get());
      }
    } else if (type == "docker") {
      Try<DockerContainerizer*> containerizer =
        DockerContainerizer::create(flags, fetcher);
      if (containerizer.isError()) {
        return Error("Could not create DockerContainerizer: " +
                     containerizer.error());
      } else {
        containerizers.push_back(containerizer.get());
      }
    } else if (type == "external") {
      Try<ExternalContainerizer*> containerizer =
        ExternalContainerizer::create(flags);
      if (containerizer.isError()) {
        return Error("Could not create ExternalContainerizer: " +
                     containerizer.error());
      } else {
        containerizers.push_back(containerizer.get());
      }
    } else {
      return Error("Unknown or unsupported containerizer: " + type);
    }
  }

  if (containerizers.size() == 1) {
    return containerizers.front();
  }

  Try<ComposingContainerizer*> containerizer =
    ComposingContainerizer::create(containerizers);

  if (containerizer.isError()) {
    return Error(containerizer.error());
  }

  return containerizer.get();
}

默认情况下,containerizerstypemesos,所以会调用MesosContainerizer::create来生成containerizer。关于resources方法,参考Mesos笔记 (5)—— 资源

 

使用LXC初体验

我使用的OSCentOS 7.1,需要安装lxclxc-templates。安装后的模板在/usr/share/lxc/templates目录下:

# ls
lxc-alpine    lxc-archlinux  lxc-centos  lxc-debian    lxc-fedora  lxc-openmandriva  lxc-oracle  lxc-sshd    lxc-ubuntu-cloud
lxc-altlinux  lxc-busybox    lxc-cirros  lxc-download  lxc-gentoo  lxc-opensuse      lxc-plamo   lxc-ubuntu

接下来以CentOS为模板创建一个container

lxc-create -t centos --name cn-centos

临时的root密码存在/var/lib/lxc/cn-01/tmp_root_pass

# cat /var/lib/lxc/cn-centos/tmp_root_pass
Root-cn-centos-EXb6bB

启动container

# lxc-start -n cn-centos

停止container

# lxc-stop -n cn-centos

参考资料:
Setup Linux Containers Using LXC On Ubuntu 15.04

 

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