OpenSSH 在連到新的 host 時會跳出 key fingerprint 的資訊讓使用者確認，有時候為了自動化會用 StrictHostKeyChecking=no 避開，在 Lobsters Daily 上則看到了新的選項可以用，StrictHostKeyChecking=accept-new：
Reading manuals is extremely helpful.
I discovered the "accept-new" option for ssh strict host key checking and now I can delete my buggy code for manually populating known_hosts. 😅
Does exactly what it says. If the host key not in known_hosts, add it. Fail otherwise. pic.twitter.com/9xsbsMcpur
— Anton Medvedev (@antonmedv) January 11, 2022
就如同選項的名字所描述的，查了一下 OpenSSH Release Notes 可以看到這是在 OpenSSH 7.5 導入的參數，是在 March 20, 2017 引入的：
* ssh(1): expand the StrictHostKeyChecking option with two new settings. The first "accept-new" will automatically accept hitherto-unseen keys but will refuse connections for changed or invalid hostkeys. This is a safer subset of the current behaviour of StrictHostKeyChecking=no. The second setting "off", is a synonym for the current behaviour of StrictHostKeyChecking=no: accept new host keys, and continue connection for hosts with incorrect hostkeys. A future release will change the meaning of StrictHostKeyChecking=no to the behaviour of "accept-new". bz#2400
對於一些自動化的流程應該夠用了，不需要到用 no 完全關掉。
翻了「Ubuntu – Package Search Results -- openssh-client」可以看到 18.04 之後都是 7.5 之後的版本了，支援度應該是沒什麼太大問題...