In Ratpack, how can I configure loading configuration from an external file? - ssl

Question

I have a Ratpack app written with the Groovy DSL. (Embedded in Java, so not a script.)
I want to load the server's SSL certificates from a config file supplied in the command line options. (The certs will directly embedded in the config, or possibly in a PEM file referenced somewhere in the config.)
For example:
java -jar httpd.jar /etc/app/sslConfig.yml
sslConfig.yml:
---
ssl:
privateKey: file:///etc/app/privateKey.pem
certChain: file:///etc/app/certChain.pem
I seem to have a chicken-and-egg problem using the serverConfig's facilities for reading the config file in order to configure the SslContext later in the serverConfig. The server config isn't created at the point I want to load the SslContext.
To illustrate, the DSL definition I have is something like this:
// SSL Config POJO definition
class SslConfig {
String privateKey
String certChain
SslContext build() { /* ... */ }
}
// ... other declarations here...
Path configPath = Paths.get(args[1]) // get this path from the CLI options
ratpack {
serverConfig {
yaml "/defaultConfig.yaml" // Defaults defined in this resource
yaml configPath // The user-supplied config file
env()
sysProps('genset-server')
require("/ssl", SslConfig) // Map the config to a POJO
ssl sslConfig // HOW DO I GET AN INSTANCE OF that SslConfig POJO HERE?
baseDir BaseDir.find()
}
handlers {
get { // ...
}
}
}
Possibly there is a solution to this (loading the SSL context in a later block?)
Or possibly just a better way to go about the whole thing..?

Answer 1

You could create a separate ConfigDataBuilder to load up a config object to deserialize your ssl config.
Alternatively, you can bind directly to server.ssl. All of the ServerConfig properties bind to the server space within the config.

Answer 2

The solution I am currently using is this, with an addition of a #builder method to SslConfig which returns a SslContextBuilder defined using its other fields.
ratpack {
serverConfig {
// Defaults defined in this resource
yaml RatpackEntryPoint.getResource("/defaultConfig.yaml")
// Optionally load the config path passed via the configFile parameter (if not null)
switch (configPath) {
case ~/.*[.]ya?ml/: yaml configPath; break
case ~/.*[.]json/: json configPath; break
case ~/.*[.]properties/: props configPath; break
}
env()
sysProps('genset-server')
require("/ssl", SslConfig) // Map the config to a POJO
baseDir BaseDir.find()
// This is the important change.
// It apparently needs to come last, because it prevents
// later config directives working without errors
ssl build().getAsConfigObject('/ssl',SslConfig).object.builder().build()
}
handlers {
get { // ...
}
}
}
Essentially this performs an extra build of the ServerConfig in order to redefine the input to the second build, but it works.