Logging - Monitoring C21

Logging and Monitoring with Graylog

Course: Logging and Monitoring - Lecturer: Margus Ernits

Group: Cyber Security Engineering (C21)

Team members: Ender Phan, Kustas Kurval, Sheela Gowry Sumathi Raju, Artur Vincent Kerge

Page created on: October 05, 2016

Abstract

In order to understand how to set up the Graylog service as well as understand its crucial roles. We decided to choose Graylog as our application for logging and monitoring. Below are our objectives which would be expected to achieve later on:

• How to install Graylog on Ubuntu 14.04.

• How to use Graylog to protect servers.

• Upgrading and configuring Graylog at first, and know how to secure Graylog.

• Threats and security during logging.

Installation Guide

Ubuntu 14.04

Prerequisites

Since the Elasticsearch is based on java, we would require to install either openJDK or Oracle JDK. It is recommended to install Oracle JDK, verify the java version by using the following command.

Remove the OpenJDK from the system, if you have it already installed. From now on it is presumed that user has root privileges.

apt-get remove --purge openjdk*

Add repository.

add-apt-repository -y ppa:webupd8team/java

Run the following command to pull the packages information from the newly added repository.

apt-get update

Issue the following command to install Java jdk 1.8.

apt-get -y install oracle-java8-installer

java -version

Output:

Java version "1.8.0_60"
Java(TM) SE Runtime Environment (build 1.8.0_60-b27)
Java HotSpot(TM) 64-Bit Server VM (build 25.60-b23, mixed mode)

Installing extras

Elasticsearch

Let’s install Elasticsearch, it can be downloaded from the official website.

Download and install GPG signing key.

wget -qO - https://packages.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -

Note that the -qO argument is lowercase Quebec followed by capital Oscar.

Save the repository definition to /etc/apt/sources.list.d/elasticsearch.list

echo "deb http://packages.elastic.co/elasticsearch/2.x/debian stable main" | sudo tee -a /etc/apt/sources.list.d/elasticsearch.list

Update repository cache and install Elasticsearch

apt-get update && apt-get install elasticsearch

Configure Elasticsearch to start during system startup.

update-rc.d elasticsearch defaults

The only important thing is to set a cluster name as “graylog2“, that is being used by graylog. Now edit the configuration file of Elasticsearch.

nano /etc/elasticsearch/elasticsearch.yml

cluster.name: graylog2

In the same file disable dynamic scripts to avoid remote execution. That can be done by adding the following line:

FOLLOWING LINE GOES INTO GRAYLOG CONF!

script.disable_dynamic: true

Once it is done, we are good to go. Before that, restart the Elasticsearch services to load the modified configuration.

service elasticsearch restart

Wait at least a minute to let the Elasticsearch get fully restarted, otherwise testing will fail. Elastisearch should be now listen on 9200 for processing HTTP request, we can use CURL to get the response. Ensure that it returns with cluster name as “graylog2”

curl -X GET http://localhost:9200

{
  "status" : 200,
  "name" : "Pistol",
  "cluster_name" : "graylog2",
  "version" : {
   "number" : "1.7.1",
   "build_hash" : "b88f43fc40b0bcd7f173a1f9ee2e97816de80b19",
   "build_timestamp" : "2015-07-29T09:54:16Z",
   "build_snapshot" : false,
   "lucene_version" : "4.10.4"
 },
 "tagline" : "You Know, for Search"
}

Optional: Use the following command to check the Elasticsearch cluster health, you must get a cluster status as “green” for graylog to work.

curl -XGET 'http://localhost:9200/_cluster/health?pretty=true'

{
 "cluster_name" : "graylog2",
 "status" : "green",
 "timed_out" : false,
 "number_of_nodes" : 1,
 "number_of_data_nodes" : 1,
 "active_primary_shards" : 0,
 "active_shards" : 0,
 "relocating_shards" : 0,
 "initializing_shards" : 0,
 "unassigned_shards" : 0,
 "delayed_unassigned_shards" : 0,
 "number_of_pending_tasks" : 0,
 "number_of_in_flight_fetch" : 0
}

MongoDB

MongoDB is available in deb format and same can be downloaded from the official website. Add the following repository information on the system to install MongoDB. Before that we must import public key.

apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv 7F0CEB10

Add repository by creating the /etc/apt/sources.list.d/mongodb-org-3.0.list list file using the command.

echo "deb http://repo.mongodb.org/apt/ubuntu trusty/mongodb-org/3.0 multiverse" | sudo tee /etc/apt/sources.list.d/mongodb-org-3.0.list

Update repository cache.

apt-get update

Install MongoDB using the following command.

apt-get install mongodb-org

Start the MongoDB service and enable it to start automatically during the system start-up.

service mongod start

No /etc/init.d/mongod :( also, why is -s argument needed for ls?

ls -s /usr/bin/mongod /etc/init.d/mongod

update-rc.d mongod defaults

Graylog2

Graylog-server accepts and process the log messages, also spawns the RESTAPI for the requests that comes from graylog-web-interface. Download the latest version of graylog from graylog.org,

Use the following command to install graylog2 repository.

wget https://packages.graylog2.org/repo/packages/graylog-1.2-repository-ubuntu14.04_latest.deb

dpkg -i graylog-1.2-repository-ubuntu14.04_latest.deb

Install https suppport and update the repository cache.

apt-get install apt-transport-https

apt-get update

Install Graylog server using following command.

apt-get install graylog-server 

Edit the server.conf file.

nano /etc/graylog/server/server.conf

Configure the following variables in the above file.

Set a secret to secure the user passwords, use the following command to generate a secret, use at least 64 character’s.

pwgen -N 1 -s 96

OH9wXpsNZVBA8R5vJQSnkhTB1qDOjCxAh3aE3LvXddtfDlZlKYEyGS24BJAiIxI0sbSTSPovTTnhLkkrUvhSSxodTlzDi5gP

If you get a “pwgen: command not found“, use the following command to install pwgen.

apt-get install pwgen

Place the secret.

password_secret = OH9wXpsNZVBA8R5vJQSnkhTB1qDOjCxAh3aE3LvXddtfDlZlKYEyGS24BJAiIxI0sbSTSPovTTnhLkkrUvhSSxodTlzDi5gP

Next is to set a hash password for the root user (not to be confused with system user, root user of graylog is admin). You will use this password for login into the web interface, admin’s password can not be changed using web interface, must edit this variable to set.

Replace “yourpassword” with the choice of your’s.

echo -n yourpassword | sha256sum

e3c652f0ba0b4801205814f8b6bc49672c4c74e25b497770bb89b22cdeb4e951

Place the hash password.

root_password_sha2 = e3c652f0ba0b4801205814f8b6bc49672c4c74e25b497770bb89b22cdeb4e951

You can setup email address root (admin) user.

root_email = "cyber.web@gmail.com"

Set timezone of root (admin) user.

root_timezone = UTC

Graylog will try to find the Elasticsearch nodes automatically, it uses multicast mode for the same. But when it comes to larger network, it is recommended to use unicast mode which is best suited one for production setups. So add the following two entries to graylog server.conf file, replace ipaddress with live hostname or ipaddress. Multiple hosts can be added with comma separated.

elasticsearch_http_enabled = false
elasticsearch_discovery_zen_ping_unicast_hosts = ipaddress:9300

Set only one master node by defining the below variable, default setting is true, you must set it as a false to make the particular node as a slave. Master node performs some periodic tasks that slave won’t perform.

is_master = true

The following variable sets the number of log messages to keep per index, it is recommended to have several smaller indices instead of larger ones.

elasticsearch_max_docs_per_index = 20000000

The following parameter defines to have total number of indices, if the this number is reached old index will be deleted.

elasticsearch_max_number_of_indices = 20

Shards setting is really depends on the number of nodes in the Elasticsearch cluster, if you have only one node, set it as 1.

elasticsearch_shards = 1

The number of replicas for your indices, if you have only one node in Elasticsearch cluster; set it as 0.

elasticsearch_replicas = 0

Restart Graylog service.

service graylog-server restart

Enable auto start of graylog server service during system startup.

update-rc.d graylog-server defaults

You can check out the server startup logs, it will be useful for you to troubleshoot graylog in case of any issue.

tailf /var/log/graylog-server/server.log

On successful start of graylog-server, you should get the following message in the log file.

2015-09-17T09:35:22.895+02:00 INFO  [ServerBootstrap] Graylog server up and running.

Install Graylog web interface:

To configure graylog-web-interface, you must have at least one graylog-server node. Install Graylog web interface using “apt-get”.

apt-get install graylog-web

Edit the configuration file and set the following parameters.

nano /etc/graylog/web/web.conf

This is the list of graylog-server nodes, you can add multiple nodes, separate by commas.

graylog2-server.uris="http://127.0.0.1:12900/"

Set the application scret and can be generated using pwgen -N 1 -s 96.

application.secret="sNXyFf6B4Au3GqSlZwq7En86xp10JimdxxYiLtpptOejX6tIUpUE4DGRJOrcMj07wcK0wugPaapvzEzCYinEWj7BOtHXVl5Z"

Set Web interface timezone.

Timezone="Europe/Tallinn"

Restart the gralog-web-interface using following command,

service graylog-web restart

Enable auto start of web interface service during system startup.

update-rc.d graylog-web defaults

Experiences

In during installation time, we have found some problems which will impact on our your installation as well.

- The version of Ubuntu and Graylog might conflict each other as well as Graylog's packages ( e.g : java )

Summary

During the installation Graylogs in both versions of Ubuntu ( 14.04 and 16.0 ). We realized that it had many differences between these versions. Listed above our objectives what we expect to achieve after installing and using Graylog, along with its useful information and its interaction between Administrator (users) with Graylog.

its advantages:

+ Free.
+ Easy to interact with web interface.
+ Easy to install with the good support from its sources.
+ Help Administrator (user) to collect information in during logging and monitoring straightforwardly.
+ Many useful tools ( plugins ) which supports to work on.

References

http://www.itzgeek.com/how-tos/linux/ubuntu-how-tos/how-to-install-graylog2-on-ubuntu-14-04.html