Error "no default routes found"

[qwtsc]

What happened:

sealer run kubernetes:v1.19.8
error: failed to get default route ip, err: no default routes found in "/proc/net/route" or "/proc/net/ipv6_route"

What you expected to happen:

successfully install cluster

How to reproduce it (as minimally and precisely as possible):

ip route without default.
#ip route
1.1.1.0/30 dev tun0 proto kernel scope link src 1.1.1.1
10.0.0.0/8 via 11.158.174.55 dev bond0
11.0.0.0/8 via 11.158.174.55 dev bond0
11.158.174.0/26 dev bond0 proto kernel scope link src 11.158.174.31
30.0.0.0/8 via 11.158.174.55 dev bond0
33.0.0.0/8 via 11.158.174.55 dev bond0
100.64.0.0/10 via 11.158.174.55 dev bond0
169.254.0.0/16 dev bond0 scope link metric 1006
172.16.0.0/12 via 11.158.174.55 dev bond0
192.168.0.0/16 via 11.158.174.55 dev bond0

Anything else we need to know?:

see similar issue reported in K3S

Environment:

• sealer version (use sealer version): v0.8.5
• Cloud provider or hardware configuration: baremetal
• OS (e.g: cat /etc/os-release):
  NAME="Alibaba Group Enterprise Linux Server"
  VERSION="7.2 (Paladin)"
  ID="alios"
  ID_LIKE="fedora anolis"
  VERSION_ID="7.2"
  PRETTY_NAME="Alibaba Group Enterprise Linux Server 7.2 (Paladin)"
  ANSI_COLOR="0;31"
  CPE_NAME="cpe:/o:alibaba:enterprise_linux:7.2:GA:server"
  HOME_URL="https://os.alibaba-inc.com/"
  BUG_REPORT_URL="https://os.alibaba-inc.com/"
• Kernel (e.g. uname -a): Linux nu2e07205.sqa.nu8 5.10.84-004.ali5000.alios7.x86_64
• Install tools: download tar && mv
• Others: nothing

[fanux]

add a default route to your host.

[qwtsc]

I do think it should be detected and added by sealer not by operator.