Connection doesn't work after workspace restart

[dimm0]

Opening VSCode from coder works on the first load. If the workspace restarts, the host ssh key changes, and connection doesn't work anymore with the error:

[13:30:19.033] stderr> debug1: Server host key: ssh-rsa SHA256:Q7o4526ZRT7PXLhauYV2lr6TgfJyD+ll1uk7HlVI03M
[13:30:19.034] stderr> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
[13:30:19.034] stderr> @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
[13:30:19.034] stderr> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
[13:30:19.034] stderr> IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
[13:30:19.034] stderr> Someone could be eavesdropping on you right now (man-in-the-middle attack)!
[13:30:19.034] stderr> It is also possible that a host key has just been changed.
[13:30:19.034] stderr> The fingerprint for the RSA key sent by the remote host is
[13:30:19.034] stderr> SHA256:Q7o4526ZRT7PXLhauYV2lr6TgfJyD+ll1uk7HlVI03M.
[13:30:19.034] stderr> Please contact your system administrator.

Manually deleting the existing host key from ssh known_hosts fixes this and makes it work again until the next restart.

Latest version of coder and all below.

[ethanndickson]

This is strange, as the SSH config the VS Code extension generates sets:

StrictHostKeyChecking no

Can you double check that's the case in your SSH config? The default location is ~/.ssh/config, and you're looking for the block starting with:

# --- START CODER VSCODE coder.example.com ---

In any case, we recently made the host key of Coder workspaces deterministic, seeded by the workspace owner username, and the name of the workspace (coder/coder#16626 coder/coder#17258). That means this will stop happening, even with strict host key checking enabled.