This guide describes the recommended way to install Graylog on RHEL/CentOS 7, 8, and 9. All links and packages are present at the time of writing.
Prerequisites
Graylog 5.0 requires the following to maintain compatibility with its software dependencies:
- OpenJDK 17 (This is embedded in Graylog 5.0 and does not need to be separately installed.)
- OpenSearch 1.x, 2.x or Elasticsearch 7.10.2
- MongoDB 5.x or 6.x
MongoDB
Installing MongoDB on Red Hat should follow the tutorial for Red Hat from the MongoDB documentation.
Graylog 5.0 is compatible with MongoDB 5.x-6.x.
1. First, add the repository file /etc/yum.repos.d/mongodb-org.repo
with the following contents:
[mongodb-org-6.0]
name=MongoDB Repository
baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/6.0/x86_64/
gpgcheck=1
enabled=1
gpgkey=https://www.mongodb.org/static/pgp/server-6.0.asc
2. After that, install the latest release of MongoDB:
sudo yum install mongodb-org
3. Additionally, run these last steps to start MongoDB:
sudo systemctl --type=service --state=active | grep mongod
OpenSearch
If you are using OpenSearch as your data node, then follow the steps below to install OpenSearch 2.0.1.
1. You may prefer to disable transparent hugepages to improve performance before installing:
sudo echo "Description=Disable Transparent Huge Pages (THP)
DefaultDependencies=no
After=sysinit.target local-fs.target
[Service]
Type=oneshot
ExecStart=/bin/sh -c 'echo never | tee /sys/kernel/mm/transparent_hugepage/enabled > /dev/null'
[Install]
WantedBy=basic.target" | sudo tee /etc/systemd/system/disable-transparent-huge-pages.service
2. Then:
sudo systemctl daemon-reload
sudo systemctl enable disable-transparent-huge-pages.service
sudo systemctl start disable-transparent-huge-pages.service
3. Install the OpenSearch GPG key:
sudo rpm --import https://artifacts.opensearch.org/publickeys/opensearch.pgp
4. Now, install the package:
sudo rpm -ivh opensearch-2.0.1-linux-x64.rpm
5. Edit the opensearch.yml
file:
sudo nano /usr/share/opensearch/config/opensearch.yml
6. At a minimum the following changes are required (for a single instance install):
cluster.name:
path.data: /var/lib/opensearch
path.logs: /var/log/opensearch
action.auto_create_index: false
plugins.security.disabled: true
network.host: 0.0.0.0
discovery.type: single-node
7. After the installation succeeds, enable the OpenSearch service:
sudo systemctl enable opensearch
8. Then, start OpenSearch:
sudo systemctl start opensearch
9. Finally, verify that OpenSearch has launched correctly:
sudo systemctl status opensearch
Elasticsearch
Elasticsearch 7.10.2 is the only version that is compatible with Graylog 5.0; however, we recommend OpenSearch for new Graylog cluster installations.
The following commands will begin the installation of the open-source version of Elasticsearch. See the Elasticsearch install page for more detailed instructions.
1. First, install the Elasticsearch GPG key:
rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch
2. Then add the repository file /etc/yum.repos.d/elasticsearch.repo
with the following contents:
sudo rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch
echo "[elasticsearch-7.10.2]
name=Elasticsearch repository for 7.10.2 packages
baseurl=https://artifacts.elastic.co/packages/oss-7.x/yum
gpgcheck=1
gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch
enabled=1
autorefresh=1
type=rpm-md" | sudo tee /etc/yum.repos.d/elasticsearch.repo
sudo yum install elasticsearch-oss
3. Install the 7.10.2 release with:
sudo yum install elasticsearch-oss
4. Modify the Elasticsearch configuration file (/etc/elasticsearch/elasticsearch.yml
), set the cluster name to graylog
, and uncomment action.auto_create_index: false
to enable the action:
echo "cluster.name: graylog
action.auto_create_index: false" | sudo tee /etc/elasticsearch/elasticsearch.yml
5. After you have modified the configuration, you can start Elasticsearch:
sudo systemctl daemon-reload
sudo systemctl enable elasticsearch.service
sudo systemctl restart elasticsearch.service
sudo systemctl --type=service --state=active | grep elasticsearch
Graylog
Now install the Graylog repository configuration and Graylog Open itself with the following commands:
sudo rpm -Uvh https://packages.graylog2.org/repo/packages/graylog-5.0-repository_latest.rpm
sudo yum install graylog-server
If you are installing Graylog Operations, then you will use the following commands:
sudo rpm -Uvh https://packages.graylog2.org/repo/packages/graylog-5.0-repository_latest.rpm
sudo yum install graylog-enterprise
Edit the Configuration File
Read the instructions within the configurations file and edit as needed, located at /etc/graylog/server/server.conf
. Additionally add password_secret
and root_password_sha2
as these are mandatory and Graylog will not start without them.
1. To create your root_password_sha2
, run the following command:
echo -n "Enter Password: " && head -1 </dev/stdin | tr -d '\n' | sha256sum | cut -d" " -f1
2. To generate a password_secret
:
pwgen -N 1 -s 96
3. To be able to connect to Graylog, set http_bind_address
to the public host name or a public IP address of the machine with which you can connect. More information about these settings can be found in Configuring the Web Interface.
4. The last step is to enable Graylog during the operating system’s start up:
sudo systemctl daemon-reload
sudo systemctl enable graylog-server.service
sudo systemctl start graylog-server.service
sudo systemctl --type=service --state=active | grep graylog
The final step is to ingest messages into your Graylog and extract the messages with extractors or use the Pipelines to work with the messages.
SELinux Information
policycoreutils-python
installed to manage SELinux.
If you’re using SELinux on your system, you need to take care of the following settings:
- Allow the web server to access the network:
sudo setsebool -P httpd_can_network_connect 1
- If the policy above does not comply with your security policy, you can also allow access to each port individually:
- Graylog REST API and web interface:
sudo semanage port -a -t http_port_t -p tcp 9000
- Elasticsearch (only if the HTTP API is being used):
sudo semanage port -a -t http_port_t -p tcp 9200
- Graylog REST API and web interface:
- Allow using MongoDB’s default port (27017/tcp):
sudo semanage port -a -t mongod_port_t -p tcp 27017
If you run a single server environment with NGINX or Apache proxy, enabling the Graylog REST API is enough. All other rules are only required in a multi-node setup. Having SELinux disabled during installation and enabling it later requires you to manually check the policies for MongoDB, OpenSearch, Elasticsearch, and Graylog.
Depending on your actual setup and configuration, you might need to add more SELinux rules to get to a running setup.
Further Reading
- https://www.nginx.com/blog/nginx-se-linux-changes-upgrading-rhel-6-6/
- https://wiki.centos.org/HowTos/SELinux
- https://wiki.centos.org/TipsAndTricks/SelinuxBooleans
- https://www.serverlab.ca/tutorials/linux/administration-linux/troubleshooting-selinux-centos-red-hat/
- https://access.Red Hat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/SELinux_Users_and_Administrators_Guide/
- https://www.digitalocean.com/community/tutorials/an-introduction-to-selinux-on-centos-7-part-1-basic-concepts
Multiple Server Setup
If you plan to have multiple server taking care of different roles in your cluster like we have in this big production setup you need to modify only a few settings. This is covered in our Multi-Node Setup guide. The Default File Location guide will give you the file you need to modify in your setup.