Updated communication docs (#745)

* updated docs

* updated pics

* Update communication.md

s/cache/storage

* Update communication.md

more comments addressed

docs/content/design/communication.md

@@ -6,60 +6,27 @@ date: 2018-02-11T15:57:56-05:00
 ## Communication flow
 
 This is the story of a time long ago. A time of myth and legend when the ancient Gods were petty and cruel and they plagued build with irreproducibility.
-Only one project dared to challenge their power...Athens. Athens possessed a strength the world had never seen. Filling its cache.
+Only one project dared to challenge their power...Athens. Athens possessed a strength the world had never seen. Filling its storage.
 
 ### Clean plate
 
-At the beginning, there's theoretical state when a cache of proxy and registry is empty.
+At the beginning, there's theoretical state when a storage of the proxy is empty.
 
 When User makes a request at this ancient time, it works as described on the flow below.
 
-- User contacts proxy asking for module M, version v1.0
-- Proxy checks whether or not it has this module in its storage. It does not.
--So it responds with a redirect to Olympus and schedules a background job to fetch the module from Olympus.
-- User receives redirect to Olympus and asks it for module M, version v1.0
-- Olympus doesn't have the module in its cache as well, so it asks the underlying VCS (e.g github.com) for a module.
-- After it receives all the bits, it stores it into its own cache and serves it to the User.
+- User runs `go get` to acquire new module.
+- Go CLI contacts the proxy asking for module M, version v1.0
+- The proxy checks whether or not it has this module in its storage. It does not.
+- The proxy downloads code from the underlying VCS and converts it into the Go Module format.
+- After it receives all the bits, it stores it into its own storage and serves it to the User.
 - User receives module and is happy.
-- Concurrently the proxy asks Olympus for module M, version v1.0 as well. Olympus, now aware of this module, serves it so proxy can fill its own cache.
+
+The process from the user using `go get` all the way to the user downloading a module is synchronous.
 
 ![Communication flow for clear state](/athens-clear-scenario.png)
 
-### New proxy joins the party
-
-At this point, we have 1 proxy and 1 registry, each of them aware about module M. Now new proxy joins with an empty cache.
-
-We can see the flow is very similar.
-
-- User contacts new proxy, which checks internal storage to find out it is missing the module.
-    - Redirects to Olympus,
-    - Schedules new cache fill job.
-- User contacts Olympus aware of the module and receives the response right away.
-- The proxy, after some time, contacts Olympus and fills its cache.
-
-![Communication flow for new proxy](/athens-new-proxy-old-olympus-scenario.png)
-
-
 ### Happy path
 
-Now that all proxies and olympus are aware of module M at version v1.0, they can all serve that module immediately to the user, without redirecting or fetching it from the VCS.
+Now that the proxy is aware of module M at version v1.0, it can serve that module immediately to the user, without fetching it from the VCS.
 
 ![Communication flow for new proxy](/athens-proxy-filled.png)
-
-
-### Private Code
-
-There are times when you do not want the mighty gods of Olympus to know about your desires. E.g:
-
-- You are requesting a private module,
-- Communication between the proxy and Olympus is disabled.
-
-In this case
-
-- User contacts proxy asking for a private module.
-- Proxy detects this repo is private and checks its storage. It does not find it there.
-- Proxy contacts internal VCS directly.
-- VCS responds with a module which is then stored in a cache Synchronously.
-- The module is served to the User.
-
-![Communication flow for new proxy](/athens-private-repo-scenario.png)