Apache NiFi: Forwarding HTTP headers

Apache NiFi can be used to expose various flavors of webservices. Using NiFi in such a way provides benefits like quick development using a GUI and of course data provenance. You know who called you with which data and where the data went. The NiFi is very scalable, delivery can be guaranteed and NiFi can help with features like back-pressure if a backend system cannot handle requests as quickly as they are offered. Exposing webservices by using NiFi, can have additional benefits such as service virtualization (decoupling). When exposing HTTP(S) webservices, a regular requirement is to pass through HTTP headers. This blog post is about how you can do that using the NiFi processors ListenHTTP, InvokeHTTP, HandleHttpRequest and HandleHttpResponse. I've used the environment which is described here.

Sonatype Nexus 3.0. Using the new Groovy API

Sonatype Nexus 3.0 does not have the REST API which was available in Nexus 2.x (see the discussion here). This provides a challenge in case you want to automate certain tasks. Nexus 3 does provide a Groovy API however which allows you to write your own scripts and upload them to Nexus. You can then call your scripts and use the JSON result. In order to get this working however, several things need to be done. First the script needs to be developed (during which code completion comes in handy). Next the script needs to be condensed to a single line and put in a JSON request. After that, the JSON request needs to be send to a specific endpoint. You can imagine this can be cumbersome. Sonatype has provided Groovy scripts to deploy their Groovy scripts. See here. I've created something similar using Python so you do not require a download of dependencies, a JVM and a Groovy installation to perform this task. This makes it more easy to do this from for example a build-server.