Ao executar o vpnc no docker, obtenha 'Não é possível abrir' / proc / sys / net / ipv4 / route / flush ': Sistema de arquivos somente leitura'

Question

Estou tentando executar o console Cisco VPN client no Docker. Eu começo o container assim:

docker run -it -v /srv/vpn/keys/:/root/keys/ --network=host --cap-add=NET_ADMIN  --device=/dev/net/tun -v /dev/net/tun:/dev/net/tun vpn-vpnc-client_img

E, em seguida, execute o cliente vpnc dentro do contêiner do Docker

vpnc-connect /root/keys/vpnc.conf --local-port 0

Produz a seguinte saída:

Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
Cannot open "/proc/sys/net/ipv4/route/flush": Read-only file system
VPNC started in background (pid: 257)...

vpnc conecta e cria rotas adequadas, portanto a VPN parece funcionar. Minha preocupação é a mensagem de aviso. De acordo com a documentação, para /proc/sys/net/ipv4/route/flush

Writing to this file results in a flush of the routing cache.

Eu não entendo essa afirmação. É essencial que o cache de roteamento não seja liberado?

Além disso, pelo que entendi, posso emitir

echo 1 > /proc/sys/net/ipv4/route/flush

manualmente após o início do contêiner. Mas eu uso monit dentro do contêiner do docker para reiniciar o vpnc se a conexão for perdida. Posso vincular a montagem /proc/sys/net/ipv4/route/flush do host dentro do contêiner de alguma forma e emitir o comando para esvaziar o cache de roteamento do script monit dentro do contêiner?