Splitting ssh config in multiple files

I have an extensive ~/.ssh/config file due to multiple credentials in differents servers for work and for personal purposes. This means different public/private ssh keys pairs, different users, different servers, etc.

My file something like :

# General configuration
Host: *
  Port 22
  IdentityFile ~/.ssh/id_rsa
  ServerAliveInterval 60
  ServerAliveCountMax 5

# Personal config
Host github
  HostName github.com
  IdentityFile ~/.ssh/github_rsa

Host lcguida
  HostName lcguida.com
  User admin

# Work servers
# ...

# Another company servers
# ...

This was OK at the beginning but as time passes and the file grows (Raspberry access, another server at work, etc, etc) this has become a huge mess.

But since the 7.3p1 release in 2016, ssh allows us to use a Include directive to import other config files. It supports the ~ shortcut as well as wildcard notation (*).

Inspired by the .d directory pattern present in many linux programs, I configured my system as the following:

├── config
├── config.d
│   ├── work.config
│   ├── home.config
│   └── code.config
└── known_hosts

So each <name>.config file has credential informations for a specific topic (work, personal, home, etc) and I have the config file configure as following:

Host *
  Port 22
  IdentityFile ~/.ssh/id_rsa
  ServerAliveInterval 60
  ServerAliveCountMax 5

Include ~/.ssh/config.d/*.config

Voilà. Sanity is back to ssh config files.