Added the infra SOPs ported to asciidoc.

modules/sysadmin_guide/pages/fedmsg-websocket.adoc

@@ -0,0 +1,70 @@
+= websocket SOP
+
+websocket communication with Fedora apps.
+
+see-also: `fedmsg-gateway.txt`
+
+== Contact Information
+
+Owner::
+  Messaging SIG, Fedora Infrastructure Team
+Contact::
+  #fedora-apps, #fedora-admin, #fedora-noc
+Servers::
+  busgateway01, proxy0*, app0*
+Purpose::
+  Expose a websocket server for FI apps to use
+
+== Description
+
+WebSocket is a protocol (an extension of HTTP/1.1) by which client web
+browsers can establish full-duplex socket communications with a server
+--the "real-time web".
+
+In our case, webapps served from app0* and packages0* will include
+javascript code instructing client browsers to establish a second
+connection to our WebSocket server. They point browsers to the following
+addresses:
+
+production::
+  wss://hub.fedoraproject.org:9939
+staging::
+  wss://stg.fedoraproject.org:9939
+
+The websocket server itself is a fedmsg-hub daemon running on
+busgateway01. It is configured to enable its websocket server component
+in the presence of certain configuration values.
+
+haproxy mediates connections to the fedmsg-hub websocket server daemon.
+An stunnel daemon provides SSL support.
+
+== Connection Flow
+
+The connection flow is much the same as in the fedmsg-gateway.txt SOP,
+but is somewhat more complicated.
+
+"Normal" HTTP requests to our app servers traverse the following chain:
+
+....
+Client -> apache(proxy01) -> haproxy(proxy01) -> apache(app01)
+....
+
+The flow for a websocket requests looks something like this:
+
+....
+Client -> stunnel(proxy01) -> haproxy(proxy01) -> fedmsg-hub(busgateway01)
+....
+
+stunnel is listening on a public port, negotiates the SSL connection,
+and redirects the connection to haproxy who in turn hands it off to the
+fedmsg-hub websocket server listening on busgateway01.
+
+At the time of this writing, haproxy does not actually load balance
+zeromq session requests across multiple busgateway0* machines, but there
+is nothing stopping us from adding them. New hosts can be added in
+ansible and pressed from busgateway01's template. Add them to the
+fedmsg-websockets listen in haproxy's config and it should Just Work.
+
+== RHIT
+
+We had RHIT open up port 9939 special to proxy01.phx2 for this.