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Connection doesn't work after workspace restart

Open dimm0 opened this issue 10 months ago • 2 comments

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.

dimm0 avatar Jan 22 '25 21:01 dimm0

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 (https://github.com/coder/coder/pull/16626 https://github.com/coder/coder/pull/17258). That means this will stop happening, even with strict host key checking enabled.

ethanndickson avatar May 01 '25 10:05 ethanndickson

That means this will stop happening, even with strict host key checking enabled.

Can we close this issue now? Or is it somehow still happening?

EhabY avatar Nov 10 '25 14:11 EhabY