Add OAB proxy config docs

[adellape]

xref: https://trello.com/c/cGffDEif

Preview:
http://file.rdu.redhat.com/~adellape/030618/oab_proxy/install_config/oab_broker_configuration.html#configuring-oab-proxy

[adellape]

Document: Document required proxy configuration for running the broker behind a proxy.

[adellape]

@eriknelson PTAL, based on openshift/ansible-service-broker#634.

[adellape]

@eriknelson This bit "explicitly if recognizes them" seems like a typo, but I wasn't sure what it should be. Maybe "explicitly if it recognizes them"?

[adellape]

The original content had dh here, though in the OCP doc we've only mentioned the dockerhub type. Are either acceptable?

[eriknelson]

There are two fields in a registry configuration, the type. In this case, only dockerhub is acceptable. The name defaults to dh, but this can be an arbitrary value. dh, or another relatively short name is preferred, as it's used as part of the ServiceClass label, which can become quite long.

[adellape]

Alternate preview from a different branch where I'm trying out splitting oab_broker_configuration.adoc into a subdir w/ separate topics:

http://file.rdu.redhat.com/~adellape/030618/oab_auth/install_config/oab/oab_proxy.html

[chengzhang1016]

Your doc should contain PR https://github.com/openshift/ansible-service-broker/pull/806/files

[adellape]

Your doc should contain PR https://github.com/openshift/ansible-service-broker/pull/806/files

@chengzhang1016 Done! http://file.rdu.redhat.com/~adellape/030618/oab_proxy/install_config/oab_broker_configuration.html#configuring-oab-proxy-cluster-proxy

[eriknelson]

Looks good and correct to me, although I think there may be a few things missing from this document that I think should be added (and I probably owe).

1. WRT: Configuring the broker for a proxy, the upstream documentation is written from a developer's perspective which are the steps required to manually configure a broker.

I'm assuming most consumers of these docs will be using openshift-ansible, which we have patched so the broker deployment inherits the cluster-wide proxy settings.

We should split the section into something like: Configuring the broker with a proxy using openshift-ansible, and then Configuring the broker manually.

2. Another default behavior for openshift-ansible is that it will generate the NO_PROXY list, and include the clusterNetworkCIDR and the serviceNetworkCIDR. It's important these are added if configuring manually. I will follow up and confirm the advised NO_PROXY list today.

[adellape]

@eriknelson @chengzhang1016 Done some rearranging / changes based on latest feedback:

http://file.rdu.redhat.com/~adellape/030618/oab_proxy/install_config/oab_broker_configuration.html#configuring-oab-proxy

[ahardin-rh]

s/vars/variables

[eriknelson]

@adellape New docs look good, that's the correct NO_PROXY 👍, ACK.