Graylog 2.3 installation with Elasticsearch5.5.X

I am going to install Graylog server 2.3  in Ubuntu 14.
For graylog setup we need to install following Mongo DB and ElasticSearch.
First install oracle jdk 8

sudo apt-get install python-software-properties
sudo add-apt-repository ppa:webupd8team/java
sudo apt-get update

Oracle JDK 8:

sudo apt-get install oracle-java8-installer

To check : $ java -version

Next Elasticsearch :

From graylog 2.3 it is supporting elasticsearch 5.X

Download and install the Debian package

$wget https://artifacts.elastic.co/downloads/elasticsearch/elasticsearch-5.5.0.deb
$sha1sum elasticsearch-5.5.0.deb
$sudo dpkg -i elasticsearch-5.5.0.deb
$sudo update-rc.d elasticsearch defaults 95 10

Elasticsearch can be started and stopped using the service command:

$sudo -i service elasticsearch start
$sudo -i service elasticsearch stop

Install MongoDB
Import the public key used by the package management system
$sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 0C49F3730359A14518585931BC711F9BA15703C6

Create a /etc/apt/sources.list.d/mongodb-enterprise.list file for MongoDB
$echo "deb [ arch=amd64 ] http://repo.mongodb.com/apt/ubuntu trusty/mongodb-enterprise/3.4 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-enterprise.list
$sudo apt-get update
$sudo apt-get install -y mongodb-enterprise

Graylog
$wget https://packages.graylog2.org/repo/packages/graylog-2.3-repository_latest.deb
$dpkg -i graylog-2.3-repository_latest.deb
$sudo apt-get update && sudo apt-get install graylog-server

For  Graylog authentication  to set username password by below steps: 

$cd /etc/graylog/server/

$vi server.conf

$apt-get install pwgen

 $pwgen -N 1 -s 96

You ll get like below ..past in server.conf

 a9ft39dMEPTmZlXOFTM4tXiD7V02StfYVNodJlgA0XmeMofVh5B3CwgngAVXXjJrJLtdiRHzG0ouI4LabzuZ7mUNH1gWSBUA

For password try below steps here admin is my password

 $echo -n admin | sha256sum

 8c6976e5b5410415bde908bd4dee15dfb167a9c873fc4bb8a81f6rf2ab48a918

Then save the above changes and start graylog server

 service graylog-server start
open
http://localhost:9000  you will get below page give login credentials which you given in graylog server.conf file