Enhance client side resolution of plain-text files

csterwa commented 6 years ago

Config server supports serving plain-text configuration files (for configuration tailored to specific libraries or environments), including placeholder resolution from config server properties. (See http://cloud.spring.io/spring-cloud-static/Dalston.SR1/#_serving_plain_text)

It seems that the only way to consume these resources (in OSS) is via RestTemplate or some similar REST client means. This can be complicated when there are additional hoops to jump through in order to resolve access to these files such as secured authentication/authorization around config server. This may require a client to muck about with authentication/authorization beans to get at the access token needed to consume those resources.

To make this easier such client situations, it would be useful to provide some means by which the clients can consume those resources, but without having to deal with the authentication/authorization specifics.

One possible (off-the-cuff) idea might be to provide some sort of ConfigServerResource or other type that would handle the OAuth concerns under the covers. Here is potential pseudo just to further elaborate the point but not yet fleshed out:

FileInputStream fis = configServer.getConfig("myapp","myprofile");

Along with auto resolution such as:

@Value("nginx.conf") // not sure this is possible with `.` in name
FileInputStream nginxConfFileStream

Regardless of the solution, ideally, the client-side piece would be part of Spring Cloud OSS generically, with hooks provided for SCS to provide OAuth details to be included in the request.

spencergibb commented 6 years ago

It wouldn't be a FileInputStream ever as it would come from a URL. I think the question we need to solve before any client api, is how would SCS provide the OAuth details?

dsyer commented 6 years ago

Seems like a generic client app concern, rather than anything to do with config server. Maybe we should think about it as a commons feature, or spring cloud security, or even Spring Boot.

ryanjbaxter commented 6 years ago

When I talked to @csterwa about this initially it was a config client feature not a server feature. My interpretation was that he just wanted a client side API that would return an InputStream rather than the developer having to figure out how to do this themselves. It seemed like more of an enhancement rather than a new feature.

dsyer commented 6 years ago

Sure, but my point was that it isn't even really a config client feature. Just a resource type / resolver (which is a core Spring Framework feature, but the security angle makes it higher level concern).

jyinpci commented 6 years ago

Regardless how it will be implemented, I think the ability to have a Spring Boot application to pull in, EASILY, plain text resources from a Spring Cloud configuration server would make Spring Boot more powerful. I have a Spring Boot app that uses different configuration files, camel routes, groovy scripts and velocity templates when being deployed for different customers. Currently, I deploy these custom files along with (but not part of) the Spring Boot fat jar. If it can easily pull in such files from the configuration server, then its deployment and maintenance would be significantly simplified.