update documentation of uwsgi-python

README.md

@@ -37,8 +37,50 @@ This role needs the patch from this [pull-request](https://github.com/ansible/an
 
 ### Variables
 
+- `app_name`: the name of the app
+- `app_user`: the user which runs the app---will be created
+- `app_group`: the user's group which runs the app---will be created
+- `app_home`: home directory of the user, usually `/var/www/<app_user>`
+- `app_path`: the path where the program can be found, usually same as `app_home`
+- `app_python_version`: the app's python version as number (2|3)
+- `app_venv`: the absolut path to the virtualenv, which shall be used for the app
+- `app_program`: the python executable, which lies in `app_path`
+- `app_callable`: uwsgi variable <callable>, mostly app
+- `app_command`: commandline arguments for the app
+- `app_mountpoint`: the path in the URI, if the app shall be reachable under https://www.example.com/app, usually /
+
+- `app_db_name`: name of the db for the app, can be `""` if not any database is needed, usally same as `app_user`
+- `app_db_type`: db type: (postgres|mysql|sqlite) 
+
+- `app_additional_software`: list of software, which is additionally needed by the app e.g. LaTeX. If no additional software is needed it is `[]`
+
+- `app_deploy_key`: path to a ssh-key which is needed to get the software usaally, "{{ inventory_dir }}/files/deploy-keys/<app_name>"
+- `app_git_url`: git url of the project 
+- `app_git_version`: git version usually `HEAD`
+
+- `app_config_file`: config file, usally `config.py`
+- `app_secret_config`: it might be useful to have the cookie's key in seperate config (true|false)
 
 
 ### How to create a new app
 
+Create the following files
+* `uwsgi-python/vars/<app_name>.yml`
+Define the variable in it from above and the variables, you need for you config file. We recommend to define them as defaults (and as documentation)
+* `uwsgi-python/templates/apps/<app_name>.j2` 
+    That's your config template.
+* `uwsgi-python/tasks/apps/<app_name>.j2` 
+    If you need some additional tasks, you can define them in this file
+    
+If you have done this, you can create an instance of the app. Note, you have to define for every app an instance altough you only want to deploy it once.
+
 ### How to create a new app's instance
+
+Create for every instance <inventory_dir>/vars/<instance_name>.yml a variable in which you can override the defaults from uwsgi-python/vars/<app_name>.yml
+
+Define in your host_vars/<host> the dictionary `webapps`
+
+webapps:
+  - instance: <instancen_name>
+    app: <app_name>
+    app_vars: "<instance_name>.yml" <-- path to variable file from above