Added file layout and purpose description to README

README.md

@@ -65,3 +65,47 @@ Testing script is *nailgun/run_tests.sh*
 Test cases:
 - nailgun/nailgun/tests/test_handlers.py
 - nailgun/nailgun/tests/test_models.py
+
+Layout
+------
+
+    Makefile - the global product makefile
+    Vagrantfile - for the vagrant dev vm
+    bin/
+        create_release - upload a release json file to nailgun (see e.g. scripts/ci/sample-release.json)
+        deploy - invoked on a node to deploy; downloads and executes recipes
+        install_cookbook - uploads cookbooks to nailgun admin API
+    bootstrap/ - creating a bootstrap image for nodes (initrd, configuration files, packages etc)
+    bootstrap2/ - same, another version?
+    ci\_with\_libvirt - libvirt-based CI tests
+    cookbooks/ - chef cookbooks to be used by nodes.
+        agent/ - node agent. Sends ohai data to admin node.
+        nailgun/ - nailgun server (not slave node!)
+        others obvious
+    devops/ - Mirantis CI framework, used by integration tests (./test/integration/). Installed on the master, not slave.
+    gnupg/
+    iso2/ - creating a bootstrap ISO for nodes [TODO How does it differ from bootstrap/ and bootstrap2/ ?]
+    lib/provision/cobbler - apparently unfinished
+    nailgun/ - server
+        manage.py, run_tests.sh - django standard
+        monitor.py - restart server when django conf files change
+        nailgun/ - django app 
+            apps: nailgun.api at api/, nailgun.webui (fully static) at /
+            models: recipe, role, release, node, cluster
+            tasks.py - django-celery tasks submitted from api/handlers.py: deploy cluster [sub: deploy node]
+                MOST IMPORTANT TASK: deploy_cluster
+                    Create databags for nodes
+                    Provision node with Cobbler - currently does nothing (?)
+                    ssh node and call /opt/nailgun/bin/deploy
+            api/ - nailgun.api django app; JSON API
+                main entities in REST API: task, recipe/release/role, node, cluster
+                
+    scripts/
+        agent/ - unfinished?
+        ci/ - scripts for CI [run on Jenkins? Unfinished?]; looks like scripts check that we can control which cookbooks are installed on nodes.
+    test/ - integration tests [TODO figure out more]
+    vagrant/ - cookbooks for use by the vagrant vm
+    requirements-deb.txt - debian packages needed on nailgun server
+    requirements.txt - ?
+    rules.mk - ?
+