WiFi配置——ubuntu20.04 server

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前段时间发现之前给老家买的mini主机很久没用了，拿来加了个无线网卡和硬盘通过nextcloud搭建一个私人网盘备份一些文件，在家里也方便手机共享。在wifi的配置时踩过一些坑，在这里简单记录下。

在ubuntu18.04中就发现使用netplan进行网络配置，WiFi同样可以通过netplan的简单配置实现上网，不需要我们在配置wpa_supplicant

netplan配置文件：

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cat /etc/netplan/00-installer-config.yaml
# This is the network config written by 'subiquity'
network:
  version: 2
  ethernets:
    enp2s0:
      dhcp4: true
      dhcp6: true
  wifis:
    wlp3s0:
      dhcp4: false
      dhcp6: true
      optional: true
      addresses: [192.168.1.38/24]
      gateway4: 192.168.1.1
      nameservers:
          addresses: [8.8.8.8]
      access-points:
          "ChinaNet-xxx":
              password: "xxxxx"

常用的命令：

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netplan generate
netplan apply
  • generate: 从/etc/netplan/*.yaml生成特定于后端的配置文件
  • apply: 应用配置(以便生效),在每一次修改完配置文件后需要执行，使配置生效

配置完成执行以上两个命令后，系统可以正常上网，但是在系统重启后存在两个问题。

  1. 系统重启时间过长，两分钟多
  2. 重启后，无线网卡可以正常配置IPv4地址，但是IPv6地址没有配置成功（nextcloud通过docker安装，局域网访问需要IPv6地址配置成功）

优化开机时间

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$systemd-analyze
Startup finished in 2.582s (firmware) + 4.843s (loader) + 5.075s (kernel) + 2min 15.951s (userspace) = 2min 28.453s
graphical.target reached after 2min 14.410s in userspace
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$systemd-analyze blame
2min 213ms systemd-networkd-wait-online.service
    7.145s docker.service

耗时最多的是systemd-networkd-wait-online.service服务其超时后才退出，主要用于检查网络配置是否成功，便于后面其他依赖于网络的服务启动，直接禁掉最省事，网络连接也不会受影响。但是netdata的服务启动会受影响导致失败，因此不能直接mark掉。

通过对系统log的分析这里主要原因是，检查网络连接失败最后导致的超时，网络链接失败是由于该主机有两张网卡（有线网卡，无线网卡），但是我没有使用，导致检查超时。由于后期可能会用到有线网卡，不打算有线网卡的检查过滤掉，同时为了方便只能牺牲一些开机时间，将该服务的超时时间重新配置为30s

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[Service]
TimeoutStartSec=30

file: /lib/systemd/system/systemd-networkd-wait-online.service

配置IPv6网络

通过系统启动日志，发现网络配置存在异常，可能是导致IPv6网络配置失败的原因

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May 24 22:36:39 ubuntu NetworkManager[874]: <warn>  [1590330999.7653] device (wlp3s0): re-acquiring supplicant interface (#1).
May 24 22:36:39 ubuntu systemd-networkd[816]: wlp3s0: Lost carrier
May 24 22:36:39 ubuntu systemd-networkd[816]: wlp3s0: Gained carrier
May 24 22:36:39 ubuntu systemd[1]: NetworkManager-dispatcher.service: Succeeded.
May 24 22:36:39 ubuntu wpa_supplicant[897]: ctrl_iface exists and seems to be in use - cannot override it
May 24 22:36:39 ubuntu wpa_supplicant[897]: Delete '/run/wpa_supplicant/wlp3s0' manually if it is not used anymore
May 24 22:36:39 ubuntu wpa_supplicant[897]: Failed to initialize control interface '/run/wpa_supplicant'.
                                            You may have another wpa_supplicant process already running or the file was
                                            left by an unclean termination of wpa_supplicant in which case you will need
                                            to manually remove this file before starting wpa_supplicant again.
May 24 22:36:39 ubuntu systemd-networkd[816]: wlp3s0: Lost carrier
May 24 22:36:39 ubuntu systemd-networkd[816]: wlp3s0: Gained carrier
May 24 22:36:39 ubuntu wpa_supplicant[897]: nl80211: deinit ifname=wlp3s0 disabled_11b_rates=0
May 24 22:36:39 ubuntu NetworkManager[874]: <error> [1590330999.9224] sup-iface[0x558f502f31f0,wlp3s0]: error adding interface: wpa_supplicant
couldn't grab this interface.
May 24 22:36:39 ubuntu NetworkManager[874]: <info>  [1590330999.9225] device (wlp3s0): supplicant interface state: starting -> down
May 24 22:36:42 ubuntu snapd[891]: stateengine.go:150: state ensure error: decode new commands catalog: net/http: request canceled (Client.
Timeout exceeded while reading body)
May 24 22:36:49 ubuntu NetworkManager[874]: <warn>  [1590331009.7629] device (wlp3s0): re-acquiring supplicant interface (#2).
May 24 22:36:49 ubuntu systemd-networkd[816]: wlp3s0: Lost carrier
May 24 22:36:49 ubuntu systemd-networkd[816]: wlp3s0: Gained carrier
May 24 22:36:49 ubuntu wpa_supplicant[897]: ctrl_iface exists and seems to be in use - cannot override it
May 24 22:36:49 ubuntu wpa_supplicant[897]: Delete '/run/wpa_supplicant/wlp3s0' manually if it is not used anymore
May 24 22:36:49 ubuntu wpa_supplicant[897]: Failed to initialize control interface '/run/wpa_supplicant'.
                                            You may have another wpa_supplicant process already running or the file was
                                            left by an unclean termination of wpa_supplicant in which case you will need
                                            to manually remove this file before starting wpa_supplicant again.
May 24 22:36:49 ubuntu systemd-networkd[816]: wlp3s0: Lost carrier
May 24 22:36:49 ubuntu systemd-networkd[816]: wlp3s0: Gained carrier

在系统的启动日志里，WiFi的配置被进行了两次，在第一次配置中日志显示ipv6地址获取成功，可能是第二次失败导致ipv6地址无法获取。

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May 26 23:00:43 ubuntu wpa_supplicant[663]: Successfully initialized wpa_supplicant
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May 26 23:00:48 ubuntu wpa_supplicant[1002]: Successfully initialized wpa_supplicant

在这里无线网络被配置两次是由于系统启动时两个网络配置的服务（NetworkManager.service，network-manager.service）都被启动了，我们禁掉NetworkManager.service服务重启后网络配置正常。

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sudo systemctl disable NetworkManager.service

netplan的配置

NetworkManager主要用于在桌面系统上管理网络设备。如果您使用NetworkManager作为网络设备管理的系统守护程序，将会使用 NetworkManager 的图形程序来管理网络接口。

在netplan的配置文件中有一个renderer字段将其指定为networkd，或许也可以解决上面的问题，没有进行验证，不过netplan手册说其是默认值。

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renderer (scalar)
       Use  the  given  networking backend for this definition.  Currently supported are networkd and NetworkManager.  This property can be
       specified globally in networks:, for a device type (in e.  g.  ethernets:) or for a particular device definition.  Default  is  net‐
       workd.

       The renderer property has one additional acceptable value for vlan objects (i.  e.  defined in vlans:): sriov.  If a vlan is defined
       with the sriov renderer for an SR-IOV Virtual Function interface, this causes netplan to set up  a  hardware  VLAN  filter  for  it.
       There can be only one defined per VF.

参考

  • systemd-networkd-wait-online拖慢Ubuntu 18.04云主机开机的排查手记
  • ubuntu命令行配置wifi，不使用NetworkManager和netplan