The SSH Config File takes the following structure:
Host hostname1
SSH_OPTION value
SSH_OPTION value
Host hostname2
SSH_OPTION value
Host *
SSH_OPTION value
Each stanza starts with the Host directive and contains specific SSH options used when establishing a connection with the remote SSH server.
The Host directive can contain one pattern or a whitespace-separated list of patterns. Each pattern can contain zero or more non-whitespace character or one of the following pattern specifiers:
* - Matches zero or more characters. For example, Host * matches all hosts, while 192.168.0.* matches hosts in the 192.168.0.0/24 subnet.? - Matches exactly one character. The pattern, Host 10.10.0.? matches all hosts in 10.10.0.[0-9] range.! - When used at the start of a pattern, it negates the match. For example, Host 10.10.0.* !10.10.0.5 matches any host in the 10.10.0.0/24 subnet except 10.10.0.5Host oci-test-instance-phoenix
HostName 192.168.1.10
User mimigonz
Port 20
IdentityFile ~/.ssh/targaryen.key
If you need to ssh into a host via a bastion, this is how you specify it
Host bastion
user bastionuser
hostname 192.168.10.100
IdentityFile ~/.ssh/bastion_key
Host cloud-instance
user instanceuser
hostname 10.1.23.146
IdentityFile ~/.ssh/cloudinstance_key
Then you can use ssh -J bastion cloud-instance
Or you could also specify the proxy jump in the ssh config
Host bastion
user bastionuser
hostname 192.168.10.100
proxyjump cloud-instance
IdentityFile ~/.ssh/bastion_key
Host cloud-instance
user instanceuser
hostname 10.1.23.146
IdentityFile ~/.ssh/cloudinstance_key
Host bm-*
User clouduser
Host jumpbox
Hostname <cloud-bastion-ocid>-<jumpbox ip>
ProxyJump bastion
Host bastion
Hostname <overlay-bastion-endpoint>
Example:
Host bm-*
User mimigonz
Host bm-amsterdam-jumpbox bm-amsterdam-jbx bm-ams-jbx
Hostname ocid1.bastion.oc1.eu-amsterdam-1.amaaaaaapvbknfyaqyos22ydj7nawvdjm7q7qfxd2vwpwt4auxay7btxwnqa-172.16.90.83
ProxyJump bm-ams
Host bm-amsterdam bm-ams
Hostname overlay-host.bastion.eu-amsterdam-1.oci.oracleiaas.com