Add user/pwd support for proxy authentication

[CEDDM]

Problem description: Retrieving apps Docker Labels behind proxy with configuration described in #4295 is not working if the proxy requires authentication.

Solution description: Add 2 properties like httpProxy.user and httpProxy.password for example to enable proxy authentication.

Description of alternatives: I tried to put username:password@host in the httpProxy.host property but I have an UnknownHostException

Additional context: Tested with SCDF 2.9.1

[jvalkeal]

@tzolov I remember we discussed this back in days when original impl were put in place. Was there more into it or was it just that we'll look it if/when request for it comes in?

[chris93111]

Hi same problem, proxy with authentification

[corneil]

@CEDDM

The properties involved are:

• http.proxyHost
• http.proxyPort
• https.proxyHost
• https.proxyPort

[markpollack]

any relation to https://github.com/spring-cloud/spring-cloud-dataflow/issues/4608 ?

[markpollack]

any relation to https://github.com/spring-cloud/spring-cloud-dataflow/issues/4818

[corneil]

I believe in the case of local deployment, kind or minikube a proxy server may become an issue and we should provide accurate documentation for use with a proxy server.

We need to:

• configure a proxy server on the network
• point the host to the proxy server
• test the configuration with local deployment and Kubernetes
• update documentation as needed