Global SSH client configuration, ssh_config(5), at scale

Turbocapitalist · 03-25-2024, 04:47 AM

I am now wondering about what kind of use-cases are out there for pushing out a modified SSH client configuration file using orchestration software.

Any descriptions of such use cases for modifying the global client configuration, no matter how vague, will be gratefully received.

Note, I am wondering only about the client ssh configuration, which would be the one normally found in /etc/ssh/ssh_config on most systems, and not for the server daemon's configuration which would be /etc/ssh/sshd_config.

michaelk · 03-25-2024, 09:56 AM

I don't know of a good reason. As far as I know the command line settings can override the user settings (~/.ssh/config) which can override the system settings (/etc/ssh/ssh_config).

Turbocapitalist · 03-25-2024, 10:17 AM

Quote:

Originally Posted by michaelk

As far as I know the command line settings can override the user settings (~/.ssh/config) which can override the system settings (/etc/ssh/ssh_config).

Yes, that's the priority. I don't know of a good reason either which is why I am now wondering, but I figure there must be some site-wide settings that institutions like to use.

wpeckham · 03-25-2024, 11:04 AM

There are wonderful mass management utilities for enterprise operations such as puppet.
Also, you CAN roll your own and we did before things like puppet became finished and general. I do not recommend rolling your own, rather evaluate existing options. These will allow you to manage much more than just the ssh client, so if that is ALL you need a roll-your-own solution might be better.

Turbocapitalist · 03-25-2024, 11:06 AM

Quote:

Originally Posted by wpeckham

There are wonderful mass management utilities for enterprise operations such as puppet.
Also, you CAN roll your own and we did before things like puppet became finished and general. I do not recommend rolling your own, rather evaluate existing options. These will allow you to manage much more than just the ssh client, so if that is ALL you need a roll-your-own solution might be better.

Yes, there are a lot of orchestration tools out there, some quite good. However, rather than which tools to use for orchestration, my question is about what kind of actual content can be pushed in the context of the SSH client's system-wide configuration file, /etc/ssh/ssh_config.

pan64 · 03-25-2024, 11:15 AM

I guess nothing "strange" but if you have something special, you can put it there. As far as I remember we don't take care of it at all.

wpeckham · 03-25-2024, 04:36 PM

Quote:

Originally Posted by Turbocapitalist

Yes, there are a lot of orchestration tools out there, some quite good. However, rather than which tools to use for orchestration, my question is about what kind of actual content can be pushed in the context of the SSH client's system-wide configuration file, /etc/ssh/ssh_config.

If you believe the proponents of those software packages there is almost nothing they CANNOT change! I have not used them enough to testify to that, but this is something pretty basic. That is a simple text file for configuration, and requires only superuser authority to change. Simple, if you start as the administrator of each system.

chrism01 · 03-26-2024, 12:44 AM

One reason for distributing a common client cfg would be if your company uses a bastion or 'jump' servers ie you do not allow direct cxns to your actual servers.
https://www.redhat.com/sysadmin/ssh-...tion-proxyjump