Update REDME.md

README.md

@@ -15,12 +15,86 @@ $ ansible-galaxy install icinga.icinga2
 The role is supported on the following platforms:
 
 * Icinga 2 >= v2.8
-* Ubuntu: 14.04, 16.04
+* Ubuntu: 16.04, 18.04
 * Debian: 8,9
 * CeontOS/RHEL: 6,7
 
 Other operating systems or versions may work but have not been tested.
 
+## Usage
+
+### Default behaviour
+
+By default this role adds the official [Icinga Repository](https://packages.icinga.com) to the system and installs the
+`icinga2` package.
+
+``` yaml
+- name: Default Example
+  hosts: localhost
+  roles:
+    - icinga2
+```
+
+### Disable repository management
+
+You may choose to use your own or the systems default repositories. Repository management can be disabled:
+
+``` yaml
+- name: Example without repository
+  hosts: all
+  roles:
+    - icinga2
+  vars:
+    - i2_manage_repository: false
+```
+
+## Reference
+
+- [**Variables**](#variables)
+    - [Variable: i2_manage_repository](#variable-i2_manage_repository)
+    - [Variable: i2_manage_package](#variable-i2_manage_package)
+    - [Variable: i2_manage_service](#variable-i2_manage_service)
+    - [Variable: i2_apt_key](#variable-i2_apt_key)
+    - [Variable: i2_apt_url](#variable-i2_apt_url)
+    - [Variable: i2_i2_yum_key](#variable-i2_yum_key)
+    - [Variable: i2_i2_yum_url](#variable-i2_yum_url)
+- [**Handlers**](#handlers)
+    - [Handler: start icinga2](#handler-start-icinga2)
+
+### Variables
+
+#### Variable: `i2_manage_repository`
+Whether to add the official [Icinga Repository](https://packages.icinga.com/) to the system or not. Defaults to `true`.
+
+#### Variable: `i2_manage_package`
+Whether to install packages or not. Defaults to `true`.
+
+#### Variable: `i2_manage_service`
+Whether to start, restart and reload the Icinga 2 on changes or not. Defaults to `true`.
+
+#### Variable: `i2_apt_key`
+GPG key used to verify packages on APT based system. The key will be imported. Defaults to
+`https://packages.icinga.com/icinga.key`.
+
+#### Variable: `i2_apt_url`
+Repository URL for APT based systems. Defaults 
+to `deb http://packages.icinga.com/{{ ansible_distribution|lower }} icinga-{{ ansible_distribution_release }} main`.
+This may be customized if you have a local mirror.
+
+#### Variable: `i2_yum_key`
+GPG key used to verify packages on YUM based sytems. The key URL will be added to the repository file. Defaults to
+`https://packages.icinga.com/icinga.key`.
+
+#### Variable: `i2_yum_url`
+Repository URL for YUM based sytem. Defaults to `http://packages.icinga.com/epel/$releasever/release/`. This may be
+customized if you have a local mirror.
+
+### Handlers
+
+#### Handler: `start icinga2`
+This handler starts Icinga 2. It is only used to make sure Icinga 2 is running. You can prevent this handler from
+being triggerd by setting `i2_manage_service` to false.
+
 ## Development
 A roadmap of this project is located at https://github.com/Icinga/ansible-icinga2/milestones. Please consider this
 roadmap when you start contributing to the project.