sshconfgen

SSH Config Generator. Generate SSH client config based on user defined conditions.

Compatible with Linux, macOS, and Windows.

Configuration

mkdir -p ~/.ssh/config.d

Create a file in ~/.ssh/config.d/ for your hosts configuration and give it the extension .sshconf.

Example Configuration

If LocalSSID, LocalGateway, or LocalPing conditions match or are reachable, the Local rules will be used. All conditions are optional, however you will need at least one condition to use the LOCAL CONFIG. You can have as many .sshconf files as you want, and they will be processed alphabetically.

• LocalSSID comma separated list of SSIDs to match.
  • (Requires networksetup on macOS, iwgetid on Linux, netsh on Windows)
    
    
• LocalGateway comma separated list of IP|MAC addresses to match. (Requires arp)
  
  
• LocalPing comma separated list of IP addresses to ping. (Requires ping)
  • Note: Ping will cause the biggest delay in runtime completion, so use it sparingly.

~/.ssh/config.d/00-myconfig.sshconf:

# CONDITIONS BEGIN
LocalSSID foo25ghz, bar5ghz
LocalGateway 192.168.1.1|00:11:22:33:44:55,172.16.1.1|00:55:44:33:22:11
LocalPing 192.168.1.100,172.16.1.100
# CONDITIONS END

# GLOBAL CONFIG BEGIN
Host aws1
	HostName 999.99.999.99
	Port 22
	User ec2-user
# GLOBAL CONFIG END

# LOCAL CONFIG BEGIN
Host homeserver1
    HostName 192.168.1.7
    Port 22
    
Host homeserver2
    HostName 192.168.1.8
    Port 22
# LOCAL CONFIG END

# REMOTE CONFIG BEGIN
Host homeserver1
    HostName mysuperawesomehomeserver1234.dyndns.org
    Port 2221
    
Host homeserver2
    HostName mysuperawesomehomeserver5678.dyndns.org
    Port 2222
# REMOTE CONFIG END

Blank template:

# CONDITIONS BEGIN
# CONDITIONS END

# GLOBAL CONFIG BEGIN
# GLOBAL CONFIG END

# LOCAL CONFIG BEGIN
# LOCAL CONFIG END

# REMOTE CONFIG BEGIN
# REMOTE CONFIG END

Usage

Run sshconfgen to generate a new ~/.ssh/config file.

sshconfgen

Run with verbose output.

sshconfgen --verbose

Print out detailed help and usage. (Contains more information than this README file.)

sshconfgen --help

Automation

macOS

LaunchAgent

Save the plist code below as local.sshconfgen.plist in ~/Library/LaunchAgents/ and run launchctl bootstrap gui/$UID ~/Library/LaunchAgents/local.sshconfgen.plist to start the agent. Note: You will need to adjust the sshconfgen path to match your installation.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" \
  "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
    <dict>
        <key>Label</key>
        <string>local.sshconfgen</string>
        <key>LowPriorityIO</key>
        <true/>
        <key>ProgramArguments</key>
        <array>
            <string>/usr/local/bin/sshconfgen</string>
        </array>
        <key>WatchPaths</key>
        <array>
            <string>/etc/resolv.conf</string>
            <string>/var/run/resolv.conf</string>
            <string>/private/var/run/resolv.conf</string>
            <string>/Library/Preferences/SystemConfiguration/NetworkInterfaces.plist</string>
            <string>/Library/Preferences/SystemConfiguration/com.apple.airport.preferences.plist</string>
        </array>
        <key>RunAtLoad</key>
        <true/>
    </dict>
</plist>