生成公私密钥

ssh-keygen -t rsa
# 提示输入的话直接回车即可
# 生成的密钥在~/.ssh/，公钥：id_rsa.pub，私钥：id_rsa

将公钥设置到目标机器

# 添加公钥到authorized_keys
cat ~/.ssh/id_rsa.pub >> ~/.ssh/authorized_keys
# 修改authorized_keys权限
chmod 600 ~/.ssh/authorized_keys