How To Install Sensu on Ubuntu 16.04 LTS

In this tutorial, we will show you how to install Sensu on Ubuntu 16.04 LTS. For those of you who didn’t know, Sensu is a free and open-source tool for composing the monitoring system you need. It is written in Ruby which uses RabbitMQ to handle messages and Redis to store data. Sensu provides a framework for monitoring infrastructure and application health. Sensu supports a number of platforms such as IBM AIX, Ubuntu, Debian, RedHat, CentOS, FreeBSD, Mac OS, Solaris, Windows, and much more.

This article assumes you have at least basic knowledge of Linux, know how to use the shell, and most importantly, you host your site on your own VPS. The installation is quite simple and assumes you are running in the root account, if not you may need to add ‘sudo‘ to the commands to get root privileges. I will show you the step-by-step installation of Sensu monitoring on Ubuntu 16.04 (Xenial Xerus).

Prerequisites

• A server running one of the following operating systems: Ubuntu 16.04, and any other Debian-based distribution like Linux Mint.
• It’s recommended that you use a fresh OS install to prevent any potential issues
• A non-root sudo user or access to the root user. We recommend acting as a non-root sudo user, however, you can harm your system if you’re not careful when acting as the root.

Install Sensu on Ubuntu 16.04 LTS

Step 1. First, make sure that all your system packages are up-to-date by running the following apt-get commands in the terminal.

sudo apt-get update
sudo apt-get upgrade

Step 2. Installing RabbitMQ.

Add Erlang repository as RabbitMQ runs on the Erlang runtime:

wget https://packages.erlang-solutions.com/erlang-solutions_1.0_all.deb
sudo dpkg -i erlang-solutions_1.0_all.deb

Add Erlang public key to your trusted key list:

wget -O- https://packages.erlang-solutions.com/ubuntu/erlang_solutions.asc |  sudo apt-key add -

Install RabbitMQ along with Erlang using the following command:

apt-get update
apt-get install -y socat erlang-nox=1:19.3-1

At this point, we can download and install RabbitMQ. As we have done for Erlang, first of all it is required to add the RabbitMQ repository:

wget http://www.rabbitmq.com/releases/rabbitmq-server/v3.6.10/rabbitmq-server_3.6.10-1_all.deb
dpkg -i rabbitmq-server_3.6.10-1_all.deb

Update the repositories and install the RabbitMQ server with the following apt command:

apt-get update
apt-get install rabbitmq-server

Once the installation is complete, start RabbitMQ and enable it to start at boot time. Execute the commands:

systemctl start rabbitmq-server
systemctl enable rabbitmq-server

Step 3. Installing Redis.

By default, Redis is available in the Ubuntu repository, so we can install it by executing the following command:

apt-get update
apt-get -y install redis-server apt-transport-https

Once the installation is complete, we can start Redis and enable it to start at boot time:

systemctl start redis-server
systemctl enable redis-server

Verify that Redis is ready to use by running the below command:

redis-cli ping

Step 4. Installing Sensu on Ubuntu 16.04.

First, Install GPG public key and add APT configuration file at /etc/apt/sources.list.d/sensu.list:

wget -O- https://sensu.global.ssl.fastly.net/apt/pubkey.gpg |  sudo apt-key add -
echo "deb https://sensu.global.ssl.fastly.net/apt sensu main" | sudo tee /etc/apt/sources.list.d/sensu.list

Install Sensu using the following command:

apt-get update
apt-get install -y sensu

Step 5. Configure Sensu.

Sensu processes require extra configuration to tell them how to connect to the RabbitMQ transport bus:

nano /etc/sensu/conf.d/rabbitmq.json

Update the file with the following values. Replace the password with the password you chose few steps back:

{
  "rabbitmq": {
    "host": "127.0.0.1",
    "port": 5672,
    "vhost": "/sensu",
    "user": "sensu",
    "password": "PASSSWD"
  }
}

Next, Create redis.json file to include the connection information for Sensu to access Redis:

nano /etc/sensu/conf.d/redis.json

Add the below lines to the above file:

{
  "redis": {
    "host": "127.0.0.1",
    "port": 6379
  }
}

Create api.json file to include the connection information for Sensu to access API service:

nano /etc/sensu/conf.d/api.json

Add below lines to the above file:

{
  "api": {
    "host": "localhost",
    "bind": "0.0.0.0",
    "port": 4567
  }
}

Step 5. Installing Uchiwa.

Sensu core does not come with the monitoring dashboard, so you would need to install Uchiwa which is an open-source dashboard for Sensu:

apt-get install uchiwa

Once the installation is finished, create a configuration file for Uchiwa:

nano /etc/sensu/conf.d/uchiwa.json

Here, paste the following content:

{"sensu": [      { "name": "Sensu",        "host": "localhost",        "port": 4567, "timeout": 10      }   ],   "uchiwa": {        "host": "0.0.0.0",        "port": 3000,       "refresh": 10        }  }

Finally, restart Sensu and Uchiwa and enable them to start at boot time:

systemctl start sensu-server
systemctl enable sensu-server
systemctl start sensu-api
systemctl enable sensu-api
systemctl start sensu-client
systemctl enable sensu-client
systemctl start uchiwa
systemctl enable uchiwa

Congratulations! You have successfully installed Sensu. Thanks for using this tutorial for installing Sensu monitoring on your Ubuntu 16.04. For additional help or useful information, we recommend you to check the official Sensu website.