Netplan

1. Preview

多年以来 Linux 管理员和用户们以相同的方式配置他们的网络接口。例如，如果你是 Ubuntu 用户，你能够用桌面 GUI 配置网络连接，也可以在 /etc/network/interfaces 文件里配置。配置相当简单且可以奏效。在文件中配置看起来就像这样

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auto enp10s0
iface enp10s0 inet static
    address 192.168.1.162
    netmask 255.255.255.0
    gateway 192.168.1.100
    dns-nameservers 1.0.0.1,1.1.1.1

尔后重启网络

  • sudo systemctl restart networking
  • sudo /etc/init.d/networking restart

但是现在，在某些发行版上（例如 Ubuntu Linux 18.04），网络的配置与控制发生了很大的变化。不需要那个 interfaces 文件和 /etc/init.d/networking 脚本，我们现在转向使用 Netplan.

1.1. 新的配置文件

如果你打算修改默认文件，我建议你先做一个备份

  • sudo cp /etc/netplan/01-netcfg.yaml /etc/netplan/01-netcfg.yaml.bak

1.2. 配置静态 IP 地址

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network:
    Version: 2
    Renderer: networkd
    ethernets:
       DEVICE_NAME:
          Dhcp4: yes/no
          Addresses: [IP/NETMASK]
          Gateway: GATEWAY
          Nameservers:
             Addresses: [NAMESERVER, NAMESERVER]

1.3. 测试配置

上面的命令会在应用配置之前验证其是否有效。如果成功，Netplan 会尝试将新的配置应用到运行的系统上。如果新的配置失败了，Netplan 会自动地恢复到之前使用的配置。

  • sudo netplan try

1.4. 应用新的配置

netplan generate：以/etc/netplan配置为管理工具生成配置

如果确信配置文件没有问题，可以跳过测试环节并且直接使用新的配置

  • sudo netplan apply

2. Introduction

During early boot, the netplan “network renderer” runs which reads /{lib,etc,run}/netplan/*.yaml and writes configuration to /run to hand off control of devices to the specified networking daemon.

在早期启动时，netplan “网络渲染器 “会运行，读取/{lib,etc,run}/netplan/*.yaml，并将配置写入/run，将设备的控制权交给指定的网络守护进程。

Configured devices get handled by systemd-networkd by default, unless explicitly marked as managed by a specific renderer (NetworkManager)

已配置的设备默认由systemd-networkd处理，除非明确标记为由特定的渲染器（NetworkManager）管理，否则默认情况下由systemd-networkd处理。

3. General structure

The top-level node in a netplan configuration file is a network: mapping that contains version: 2 (the YAML currently being used by curtin, MaaS, etc. is version 1), and then device definitions grouped by their type, such as ethernets:, modems:, wifis:, or bridges:. These are the types that our renderer can understand and are supported by our backends.

4. Device configuration IDs

The key names below the per-device-type definition maps (like ethernets:) are called “ID”s. They must be unique throughout the entire set of configuration files.

If an interface is defined with an ID in a configuration file; it will be brought up by the applicable renderer. To not have netplan touch an interface at all, it should be completely omitted from the netplan configuration files.

每个设备类型定义映射下面的关键名称（如ethernets:）被称为 “ID “s。

如果一个接口在配置文件中定义了一个ID，那么它将被适用的渲染器调出。要想让 netplan 完全不接触到某个接口，应该从 netplan 配置文件中完全省略。

4.1. Physical devices

  • Examples: ethernet, modem(调制解调器), wifi
  • Examples: veth, bridge, bond

    这些设备完全由配置文件和网络栈控制。也就是说，这些设备是被创建的，而不是被匹配的。因此match:和set-name:对这些不适用，ID字段是创建的虚拟设备的名称

4.2. Virtual devices

  • Examples: veth, bridge, bond

    these devices are being created instead of matched. Thus match: and set-name: are not applicable for these, and the ID field is the name of the created virtual device.

5. Common properties for physical device types

  • match
    • name
    • macaddress
    • driver

5.1. example

  • all cards on second PCI bus:
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    match:
      name: enp2*
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network:
    version: 2
    ethernets:
        ens3:
            match:
                macaddress: 52:54:00:f0:bc:02
            dhcp4: true

In the old world you’d match by the name ens3 and not specify a MAC. This is not how netplan works - in netplan what matters is the match stanza.

And you can use DHCP and static IPs together - this will give an interface both static and dynamic address

6. 参考