Host key mismatch

[aquarelacs-rodrigo-araujo]

If you are trying to resolve an environment-specific issue or have a one-off question about the edge case that does not require a feature then please consider asking a question in argocd slack channel.

Checklist:

• [ x] I've searched in the docs and FAQ for my answer: https://bit.ly/argocd-faq.
• I've included steps to reproduce the bug.
• [ x ] I've pasted the output of argocd version.

Describe the bug

I have a private github repository configured in argocd for my applications, recently we had a problem with this repository failing to connect without any previous changes to the ssh key of github or argocd.

After recreating the connection to the repository using the insecure-ignore-host-key flag, the connection works.

I would like to find the root cause of this issue to mitigate any eventualities in the future.

To Reproduce

Unable to reproduce the error

Expected behavior

As the key is valid, I hope the connection with the repository is successful.

Screenshots

Version

v2.0.2+9a7b0bc

Logs

time="2021-11-16T19:43:43Z" level=info msg="finished unary call with code OK" grpc.code=OK grpc.method=Check grpc.request.deadline="2021-11-16T19:44:43Z" grpc.service=grpc.health.v1.Health grpc.start_time="2021-11-16T19:43:43Z" grpc.time_ms=0.126 span.kind=server system=grpc

[mabushey]

We have this problem too. This redhat ticket from yesterday ( https://access.redhat.com/solutions/6517171 ) says:
Issue: SSH from GitOps to github began failing after Github.com made changes to their SSH endpoint.

[brsolomon-deloitte]

Related: #7725, #7723

[alexmt]

Fixed by #7722 . The fix is available in v2.1.7 release

[kelveden]

For anyone who has arrived here trying to fix the same problem but via the official helm chart. (Currently the latest Argo version in the chart is 2.1.6.)

A workaround that worked for me was to add this to the helm manifest:

configs:
  knownHosts:
    data:
      ssh_known_hosts: |
        github.com ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAyNTYAAABBBEmKSENjQEezOmxkZMy7opKgwFB9nkt5YRrYMjNuG5N87uRgg6CLrbo5wAdT/y6v0mKV0U2w0WZ2YB/++Tpockg=
        github.com ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIOMqqnkVzrm0SdG6UOoqKLsabgH5C9okWi0dh2l9GKJl

IMPORTANT: I've only added the two new github.com keys added in the fix #7722; so if you need access to hosts other than github.com, you'll need to add those keys in too.