How to enable CORS on Sonatype Nexus?

Question

I want to develop a Monitoring-WebApp for different things with AngularJS as Frontend. One of the core-elements is showing an overview of Nexus-Artifacts/Repositories. When I request the REST-API I'm getting following error back:

No 'Access-Control-Allow-Origin' header is present on the requested resource.
Origin 'http://localhost:9090' is therefore not allowed access.

To fix this error, I need to modify the response headers to enable CORS.

It would be great if anyone is familiar with that type of problem and could give me an answer!

Answer 1

The CORS headers are present in the response of the system you are trying to invoke. (Those are checked on the client side [aka browser this case], you can implement a call on your backend to have those calls and there you can ignore those headers, but that could become quite hard to maintain.) To change those you'll need a proxy. So your application will not call the url directly like

fetch("http://localhost:9090/api/sometest")

There are at least two ways: one to add a proxy directly before the sonar server and modify the headers for everyone. I do not really recommend this because of security reasons. :)

The other more maintaneable solution is to go through the local domain of the monitoring web app as follows:

fetch("/proxy/nexus/api/sometest")

To achieve this you need to setup a proxy where your application is running. This could map the different services which you depend on, and modify the headers if necessary.

I do not know which application http server are you going to use, but here are some proxy configuration documentations on the topic:

For Apache HTTPD mod_proxy you could use a configuration similar to this:

ProxyPass "/proxy/nexus/" "http://localhost:9090/"
ProxyPassReverse "/proxy/nexus/" "http://localhost:9090/"

It is maybe necessary to use the cookies as well so you may need to take a look at the following configurations:

• ProxyPassReverseCookiePath
• ProxyPassReverseCookieDomain

For Nginx location you could employ something as follows

location /proxy/nexus/ {
    proxy_pass http://localhost:9090/;
}

For node.js see documentation: https://github.com/nodejitsu/node-http-proxy

module.exports = (req, res, next) => {

  proxy.web(req, res, {
    target: 'http://localhost:4003/',
    buffer: streamify(req.rawBody)
  }, next);

};