SSH Config Parser & Stringifier
Usage
const SSHConfig = require('ssh-config')
const config = SSHConfig.parse(`
IdentityFile ~/.ssh/id_rsa
Host tahoe
HostName tahoe.com
Host walden
HostName waldenlake.org
Host *
User keanu
ForwardAgent true
`)
expect(config).to.eql(
[ { "param": "IdentityFile",
"value": "~/.ssh/id_rsa" },
{ "param": "Host",
"value": "tahoe",
"config":
[ { "param": "HostName",
"value": "tahoe.com" } ] },
{ "param": "Host",
"value": "walden",
"config":
[ { "param": "HostName",
"value": "waldenlake.org" } ] },
{ "param": "Host",
"value": "*",
"config":
[ { "param": "User",
"value": "keanu" },
{ "param": "ForwardAgent",
"value": "true" } ] } ]
)
// Change the HostName in the Host walden section
const section = config.find({ Host: 'walden' })
for (const line of section.config) {
if (line.param === 'HostName') {
line.value = 'waldenlake.org'
break
}
}
// The original whitespaces and comments are preserved.
console.log(SSHConfig.stringify(config))
// console.log(config.toString())
Iterating over Sections
One needs to iterate over ssh configs mostly because of two reasons.
- to
.findthe corresponding section and modify it, or - to
.computethe ssh config about certainHost.
.compute Parameters by Host
You can use config.compute method to compute applied parameters of certain host.
expect(config.compute('walden')).to.eql({
IdentityFile: [
'~/.ssh/id_rsa'
],
Host: 'walden',
HostName: 'waldenlake.org',
User: 'nil',
ForwardAgent: 'true'
})
NOTICE According to ssh_config(5), the first obtained parameter value will be used. So we cannot override existing parameters. It is suggested that the general settings shall be at the end of your config file.
The IdentityFile parameter always contain an array to make possible multiple IdentityFile settings to be able to coexist.
.find sections by Host or Match
NOTICE: This method is provided to find the corresponding section in the parsed config for config manipulation. It is NOT intended to compute config of certain Host. For latter case, use .compute(host) instead.
To ditch boilerplate codes like the for loop shown earlier, we can use the .find(opts) available in the parsed config object.
config.find({ Host: 'example1' })
// or the ES2015 Array.prototype.find
config.find(line => line.param == 'Host' && line.value == 'example1')
.remove sections by Host or other criteria
To remove sections, we can pass the section to .remove(opts).
config.remove({ Host: 'example1' })
.append sections
Since the parsed config is a sub class of Array, you can append new sections with methods like .push or .concat.
config.push(SSHConfig.parse(`
Host ness
HostName lochness.com
User dinosaur
`))
expect(config.find({ Host: '*' })).to.eql(
{ "param": "Host",
"value": "ness",
"config":
[ { "param": "HostName",
"value": "lochness.com" } ] }
)
If the section to append is vanilla JSON, .append is what you need.
const config = new SSHConfig()
config.append({
Host: 'ness',
HostName: 'lochness.com',
User: 'dinosaur'
})
SSHConfig.stringify(config)
// =>
// Host ness
// HostName lochness.com
// User dinosaur