为跳板机创建跳转用户限制ssh登陆

server

create a user without shell access(proxy jump only)

sudo -i
useradd jump -m -d /home/jump -s /home/jump/nologin
cd /home/jump
cat <<EOF >> nologin
#!/bin/bash
echo "Hi there! You've successfully authenticated, but we do not provide shell access."
EOF
chmod +x nologin
touch .hushlogin
mkdir -m 700 .ssh
chmod 600 .ssh/authorized_keys >> !#:2
chown -R jump:jump .ssh
vi .ssh/authorized_keys
# paste your public key here
ZZ

client

modify ~/.ssh/config

Host dev
    HostName 192.168.1.123
    User your_name
    ProxyJump jump@ip_jump_host:port

tested on vscode remote and ssh