This guide describes the fastest way to install Graylog on CentOS 7. All links and packages are present at the time of writing but might need to be updated later on.
This setup should not be done on publicly exposed servers. This guide does not cover security settings!
Taking a minimal server setup as base will need this additional packages:
$ sudo yum install java-1.8.0-openjdk-headless.x86_64
If you want to use
pwgen later on you need to Setup EPEL on your system with
sudo yum install epel-release and install the package with
sudo yum install pwgen.
Installing MongoDB on CentOS should follow the tutorial for RHEL and CentOS from the MongoDB documentation. First add the repository file
/etc/yum.repos.d/mongodb-org.repo with the following contents:
[mongodb-org-4.0] name=MongoDB Repository baseurl=https://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/4.0/x86_64/ gpgcheck=1 enabled=1 gpgkey=https://www.mongodb.org/static/pgp/server-4.0.asc
After that, install the latest release of MongoDB with
sudo yum install mongodb-org.
Additionally, run these last steps to start MongoDB during the operating system’s boot and start it right away:
$ sudo systemctl daemon-reload $ sudo systemctl enable mongod.service $ sudo systemctl start mongod.service
Graylog can be used with Elasticsearch 6.x, please follow the installation instructions from the Elasticsearch installation guide.
First install the Elastic GPG key with
rpm --import https://artifacts.elastic.co/GPG-KEY-elasticsearch then add the repository file
/etc/yum.repos.d/elasticsearch.repo with the following contents:
[elasticsearch-6.x] name=Elasticsearch repository for 6.x packages baseurl=https://artifacts.elastic.co/packages/oss-6.x/yum gpgcheck=1 gpgkey=https://artifacts.elastic.co/GPG-KEY-elasticsearch enabled=1 autorefresh=1 type=rpm-md
followed by the installation of the latest release with
sudo yum install elasticsearch-oss.
Make sure to modify the Elasticsearch configuration file (
/etc/elasticsearch/elasticsearch.yml) and set the cluster name to
graylog additionally you need to uncomment (remove the # as first character) the line, and add
action.auto_create_index: false to the configuration file:
cluster.name: graylog action.auto_create_index: false
After you have modified the configuration, you can start Elasticsearch:
$ sudo systemctl daemon-reload $ sudo systemctl enable elasticsearch.service $ sudo systemctl restart elasticsearch.service
Now install the Graylog repository configuration and Graylog itself with the following commands:
$ sudo rpm -Uvh https://packages.graylog2.org/repo/packages/graylog-3.0-repository_latest.rpm $ sudo yum install graylog-server
Follow the instructions in your
/etc/graylog/server/server.conf and add
root_password_sha2. These settings are mandatory and without them, Graylog will not start!
You need to use the following command to create your
echo -n "Enter Password: " && head -1 </dev/stdin | tr -d '\n' | sha256sum | cut -d" " -f1
To be able to connect to Graylog you should set
http_bind_address to the public host name or a public IP address of the machine you can connect to. More information about these settings can be found in Configuring the web interface.
If you’re operating a single-node setup and would like to use HTTPS for the Graylog web interface and the Graylog REST API, it’s possible to use NGINX or Apache as a reverse proxy.
The last step is to enable Graylog during the operating system’s startup:
$ sudo systemctl daemon-reload $ sudo systemctl enable graylog-server.service $ sudo systemctl start graylog-server.service
We assume that you have
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, Elasticsearch and Graylog.
Depending on your actual setup and configuration, you might need to add more SELinux rules to get to a running setup.
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.