SSH Tunnel "Failed to connect"

[chewsa]

I’m trying to get our Looker instance to connect to Redshift via an SSH tunnel. Our looker instance is managed by Looker (not self-hosted). Version is 22.14.44.

The SSH server is an AWS EC2 instance with a public IP address. 

I’ve verified that our set-up works because our dbt Cloud projects can successfully read/write from/to the Redshift instance via SSH using the same server. 

At a high level, I’ve

• created the user that Looker should use to SSH
• Added the public key to /home/username/.ssh/authorized_keys 
• whitelisted the public IPs for the EC2 security group, the same place where I whitelisted dbt Cloud’s IP addresses. The following IPs were whitelisted
  • 34.87.134.202
  • 34.143.132.206
  • 34.143.210.116

I retried this by following this document: https://cloud.google.com/looker/docs/using-an-ssh-tunnel#using_the_database_server

But I am met with the same error. “Failed to connect”

A vague error

The `Log` section in the Admin UI doesn’t seem to provide more information. 

Has anyone encountered this issue before? If so, what else should I be checking?