https://gist.github.com/nicornk/5d2c0cd02179f9b46cc7df459af0...
host i-* IdentityFile ~/.ssh/id_rsa TCPKeepAlive yes ServerAliveInterval 120 User ec2-user ProxyCommand sh -c "aws ec2 start-instances --instance-ids %h ; aws ec2 wait instance-running --instance-ids %h ; aws ec2-instance-connect send-ssh-public-key --instance-id %h --instance-os-user %r --ssh-public-key 'file://~/.ssh/id_rsa.pub' --availability-zone $(aws ec2 describe-instances --instance-ids %h --query 'Reservations[0].Instances[0].Placement.AvailabilityZone') ; aws ssm start-session --target %h --document-name AWS-StartSSHSession --parameters 'portNumber=%p'"
This will also allow VSCode remote development.
I've used a combination of ProxyCommand directive in ssh config + a script it calls w/ the `%h` (host) to unpack what the correct instance-id is (like @galanwe). For the proxycommand, you can embed an `aws ec2-instance-connect send-ssh-public-key` for pushing a key valid for 60s followed by activating the SSM session.
The downside is it adds ~20-30s delay in connection due to the API requests, but if you're making repeated rapid requests to same instance, I recommend looking into ssh's ControlPath, ControlMaster and ControlPersist to keep a longer lived session that's re-used for client re-connections (ref: https://blog.scottlowe.org/2015/12/11/using-ssh-multiplexing...)
[Edit to add that I've hit the registry bug myself]
I’m surprised this hasn’t come up more frequently. I’d expect a lot of security products to flag it as very much looking like malware.
What do you suggest as an alternative? Session Manager is IAM controlled and much more secure and easily managed than the traditional means involving direct access via SSH and opening a port through the security group for a certain IP address or a jump box server.
An SSM client library is super helpful for embedding the tunneling into the client app. At a previous employer, we'd access jumphosts from AWS Session Manager and GCP Identity Aware Proxy and were looking to embed that connection flow into some cli management utilities to ease use. At the time, we ended up starting the tunneling processes separately inside the code but it would have been much nicer and easier with a library.
