Elasticsearch single-node cluster

Prerequisites

Open Distro for Elasticsearch requires the Java Development Kit and other packages installation including wget, curl, and unzip that will be used in further steps:

Adding the Wazuh repository

Elasticsearch installation

Install Open Distro for Elasticsearch:

Elasticsearch configuration

Once Elasticsearch is installed, download the pre-configured configuration file:

# curl -so /etc/elasticsearch/elasticsearch.yml https://raw.githubusercontent.com/wazuh/wazuh-documentation/4.0/resources/open-distro/elasticsearch/7.x/elasticsearch.yml

This file configures Elasticsearch to use 0.0.0.0 for the network.host variable, so it will accept communications directed to any of its IP addresses instead of binding to the IP of a specific network interface in the host. Access may be restricted to a specific network interface by specifying its IP in this setting so Elasticsearch may not be unnecessarily exposed.

Elasticsearch roles and users

In order to use the Wazuh Kibana plugin properly, it is necessary to add the extra roles and users:

# curl -so /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/roles.yml https://raw.githubusercontent.com/wazuh/wazuh-documentation/4.0/resources/open-distro/elasticsearch/roles/roles.yml
# curl -so /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/roles_mapping.yml https://raw.githubusercontent.com/wazuh/wazuh-documentation/4.0/resources/open-distro/elasticsearch/roles/roles_mapping.yml
# curl -so /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/internal_users.yml https://raw.githubusercontent.com/wazuh/wazuh-documentation/4.0/resources/open-distro/elasticsearch/roles/internal_users.yml

The commands above add the following Wazuh users in Kibana:

Two additional roles are added, whose function is to give the appropriate permissions to users:

These users and roles are designed to operate along with the Wazuh Kibana plugin and they are protected so they cannot be modified from the Kibana’s interface. To modify them or add new users or roles, the securityadmin script has to be run.

Certificates creation and deployment

1. Remove the demo certificates:

   # rm /etc/elasticsearch/esnode-key.pem /etc/elasticsearch/esnode.pem /etc/elasticsearch/kirk-key.pem /etc/elasticsearch/kirk.pem /etc/elasticsearch/root-ca.pem -f
   

2. Generate and deploy the certificates:

   • Move to the installation location and create the certificates directory:

     # mkdir /etc/elasticsearch/certs
     # cd /etc/elasticsearch/certs
     

   • Download the Search Guard offline TLS tool to create the certificates:

     # curl -so ~/search-guard-tlstool-1.8.zip https://maven.search-guard.com/search-guard-tlstool/1.8/search-guard-tlstool-1.8.zip
     

   • Extract the downloaded file. It is assumed that it has been downloaded in ~/ (home directory):

     # unzip ~/search-guard-tlstool-1.8.zip -d ~/searchguard
     

   • Download the search-guard.yml configuration file. Choose either Wazuh single-node cluster if there is only one Wazuh server, or Wazuh multi-node cluster in case of having more than one Wazuh servers:

     Wazuh single-node clusterWazuh multi-node cluster

     # curl -so ~/searchguard/search-guard.yml https://raw.githubusercontent.com/wazuh/wazuh-documentation/4.0/resources/open-distro/searchguard/single-node/search-guard.yml
     

     After downloading the configuration file in ~/searchguard/search-guard.yml, replace the values <elasticsearch_IP> and <kibana_ip> with the corresponding IP addresses. More than one IP can be specified (one entry per line):

     # Nodes certificates
     nodes:
       - name: elasticsearch
         dn: CN=node-1,OU=Docu,O=Wazuh,L=California,C=US
         ip:
           - <elasticsearch_IP>
       - name: kibana
         dn: CN=kibana,OU=Docu,O=Wazuh,L=California,C=US
         ip:
           - <kibana_ip>
     

     To learn more about how to create and configure the certificates visit the Certificates deployment section.

   • Run the Search Guard's script to create the certificates:

     # ~/searchguard/tools/sgtlstool.sh -c ~/searchguard/search-guard.yml -ca -crt -t /etc/elasticsearch/certs/
     

     In case of further certificates deployments, it is highly recommended to keep Search Guard's TLS offline tool and its configuration file search-guard.yml on the master node.

   • Compress all the necessary files to be sent to the all the instances:

     # tar -cf /etc/elasticsearch/certs/certs.tar *
     

   • Copy certs.tar to all the servers of the distributed deployment. This can be done by using, for example, scp.

   • Remove unnecessary files:

     # rm /etc/elasticsearch/certs/client-certificates.readme /etc/elasticsearch/certs/elasticsearch_elasticsearch_config_snippet.yml search-guard-tlstool-1.7.zip filebeat* -f
     

   • If Kibana will be installed in this node, keep the certificates file. Otherwise, if the file has been already copied to all the instances of the distributed deployment, remove it to increase security rm -f certs.tar.

3. Enable and start the Elasticsearch service:

   SystemdSysV Init

   # systemctl daemon-reload
   # systemctl enable elasticsearch
   # systemctl start elasticsearch
   

4. Run the Elasticsearch's securityadmin script to load the new certificates information and start the cluster. To run this command, the value <elasticsearch_IP> must be replaced by the Elasticsearch installation IP:

# /usr/share/elasticsearch/plugins/opendistro_security/tools/securityadmin.sh -cd /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/ -nhnv -cacert /etc/elasticsearch/certs/root-ca.pem -cert /etc/elasticsearch/certs/admin.pem -key /etc/elasticsearch/certs/admin.key -h <elasticsearch_IP>

Run the following command to ensure that the installation has been successful:

# curl -XGET https://localhost:9200 -u admin:admin -k

An example response should look as follows:

 {
   "name" : "node-1",
   "cluster_name" : "elasticsearch",
   "cluster_uuid" : "2gIeOOeUQh25c2yU0Pd-RQ",
   "version" : {
     "number" : "7.9.1",
     "build_flavor" : "oss",
     "build_type" : "rpm",
     "build_hash" : "083627f112ba94dffc1232e8b42b73492789ef91",
     "build_date" : "2020-09-01T21:22:21.964974Z",
     "build_snapshot" : false,
     "lucene_version" : "8.6.2",
     "minimum_wire_compatibility_version" : "6.8.0",
     "minimum_index_compatibility_version" : "6.0.0-beta1"
   },
   "tagline" : "You Know, for Search"
 }

It is highly recommended to change Elasticsearch’s default passwords for the users found at the /usr/share/elasticsearch/plugins/opendistro_security/securityconfig/internal_users.yml file. More information about this process can be found here. It is also recommended to customize the file /etc/elasticsearch/jvm.options in order to improve the performance of Elasticsearch. Learn more about this process in the Elasticsearch tuning section.

To uninstall Elasticsearch, visit the uninstalling section.