added the folder structure and general explanation to examples, removed module name typo

web_infrastructure/deploy_helper.py

@@ -104,22 +104,69 @@ notes:
 
 EXAMPLES = '''
 
+# General explanation, starting with an example folder structure for a project:
+
+root:
+    releases:
+        - 20140415234508
+        - 20140415235146
+        - 20140416082818
+
+    shared:
+        - sessions
+        - uploads
+
+    current: -> releases/20140416082818
+
+
+The 'releases' folder holds all the available releases. A release is a complete build of the application being
+deployed. This can be a clone of a repository for example, or a sync of a local folder on your filesystem.
+Having timestamped folders is one way of having distinct releases, but you could choose your own strategy like
+git tags or commit hashes.
+
+During a deploy, a new folder should be created in the releases folder and any build steps required should be
+performed. Once the new build is ready, the deploy procedure is 'finalized' by replacing the 'current' symlink
+with a link to this build.
+
+The 'shared' folder holds any resource that is shared between releases. Examples of this are web-server
+session files, or files uploaded by users of your application. It's quite common to have symlinks from a release
+folder pointing to a shared/subfolder, and creating these links would be automated as part of the build steps.
+
+The 'current' symlink points to one of the releases. Probably the latest one, unless a deploy is in progress.
+The web-server's root for the project will go through this symlink, so the 'downtime' when switching to a new
+release is reduced to the time it takes to switch the link.
+
+To distinguish between successful builds and unfinished ones, a file can be placed in the folder of the release
+that is currently in progress. The existence of this file will mark it as unfinished, and allow an automated
+procedure to remove it during cleanup.
+
+
 # Typical usage:
 - name: Initialize the deploy root and gather facts
   deploy_helper: path=/path/to/root
 - name: Clone the project to the new release folder
-  git: repo=git://foosball.example.org/path/to/repo.git dest={{ deploy.new_release_path }} version=v1.1.1"
+  git: repo=git://foosball.example.org/path/to/repo.git dest={{ deploy_helper.new_release_path }} version=v1.1.1
 - name: Add an unfinished file, to allow cleanup on successful finalize
-  file: path={{ deploy.new_release_path }}/{{ deploy.unfinished_filename }} state=touch
+  file: path={{ deploy_helper.new_release_path }}/{{ deploy_helper.unfinished_filename }} state=touch
 - name: Perform some build steps, like running your dependency manager for example
-  composer: command=install working_dir={{ deploy.new_release_path }}
+  composer: command=install working_dir={{ deploy_helper.new_release_path }}
+- name: Create some folders in the shared folder
+  file: path='{{ deploy_helper.shared_path }}/{{ item }}' state=directory
+  with_items: ['sessions', 'uploads']
+- name: Add symlinks from the new release to the shared folder
+  file: path='{{ deploy_helper.new_release_path }}/{{ item.path }}'
+        src='{{ deploy_helper.shared_path }}/{{ item.src }}'
+        state=link
+  with_items:
+      - { path: "app/sessions", src: "sessions" }
+      - { path: "web/uploads",  src: "uploads" }
 - name: Finalize the deploy, removing the unfinished file and switching the symlink
   deploy_helper: path=/path/to/root release={{ deploy_helper.new_release }} state=finalize
 
 # Retrieving facts before running a deploy
-- name: Run query to gather facts without changing anything
+- name: Run 'state=query' to gather facts without changing anything
   deploy_helper: path=/path/to/root state=query
-  # Remember to set the 'release' parameter when you actually call state=present
+# Remember to set the 'release' parameter when you actually call 'state=present' later
 - name: Initialize the deploy root
   deploy_helper: path=/path/to/root release={{ deploy_helper.new_release }} state=present
 
@@ -129,7 +176,7 @@ EXAMPLES = '''
                  shared_path=/var/www/shared
                  current_path=/var/www/active
 
-# Using your own naming strategy:
+# Using your own naming strategy for releases (a version tag in this case):
 - deploy_helper: path=/path/to/root release=v1.1.1 state=present
 - deploy_helper: path=/path/to/root release={{ deploy_helper.new_release }} state=finalize
 
@@ -142,12 +189,22 @@ EXAMPLES = '''
 # Postponing the cleanup of older builds:
 - deploy_helper: path=/path/to/root release={{ deploy_helper.new_release }} state=finalize clean=False
 - deploy_helper: path=/path/to/root state=clean
+# Or running the cleanup ahead of the new deploy
+- deploy_helper: path=/path/to/root state=clean
+- deploy_helper: path=/path/to/root state=present
 
 # Keeping more old releases:
 - deploy_helper: path=/path/to/root release={{ deploy_helper.new_release }} state=finalize keep_releases=10
-# Or:
+# Or, if you use 'clean=false' on finalize:
 - deploy_helper: path=/path/to/root state=clean keep_releases=10
 
+# Removing the entire project root folder
+- deploy_helper: path=/path/to/root state=absent
+
+# Debugging the facts returned by the module
+- deploy_helper: path=/path/to/root
+- debug: var=deploy_helper
+
 '''
 
 class DeployHelper(object):