Update README.md file

README.md

@@ -1,2 +1,30 @@
 # Graylog
-Shell script to install automatically Graylog application
+
+## Description
+This shell script installs all Graylog components (server and web) on one server.
+
+## Prerequisites
+- [x] Processor type : 64Bits
+- [x] Operating System : CentOS
+- [x] OS versions : 6.5, 6.6
+- [x] OS installation : Minimal
+- [x] Minimum RAM size : 1Go
+- [x] Minimum disk size : 60Go
+
+## Quick guide
+1. Create new file in your home folder
+  - `touch ~/install_graylog.sh`
+2. Edit it with Vi editor
+  - `vi ~/install_graylog.sh`
+3. In Vi console
+  * Press `<i>` to go in edit mode,
+  * Paste content from [Github](https://github.com/mikael-andre/Graylog/blob/master/install_graylog.sh),
+  * Press `<ESCAPE>` to exit edit mode,
+  * Type `:x` and press `<ENTER>` to save and close file
+4. Give execute rights on install script
+  - `chmod +x ~/install_graylog.sh`
+5. Launch it with the following command
+  - `~/install_graylog.sh`
+
+## Contact
+Feel free to contact me by mail or Github if you have any issues or suggestions.