Generic CLI-metrics Prometheus exporter.

This is an exporter that was originally created to expose the power consumption measurement given by the below-included command, but it is so generic that could be adapted fairly simply to expose any other desired command-line variable. The instructions describe the installation of an ipmi-exporter, but changing the name both in the directories and files will generate no problems at all.

ipmi-sensors -h localhost --no-sensor-type-output --no-header-output --comma-separated-output --sensor-types Current

To change or add new exposed metrics, the function getPower inside collector.go needs to be changed or duplicated. That function launches a command, captures the output and isolates the desired metric. In addition, new variables should be defined as var powerConsumption inside of collector.go.

Installation guide.

0. Pre-requisites.

• Golang. It is mandatory to have one of the latest versions to support some of the network functionalities. (The current implementation was compiled with the 1.13 version)
• Sudo access to create new users and services to run the exporter. Besides, the above included ipmi command requires sudo to be executed.

1. Creating a new user and setting up the environment.

There is going to be a user created to run this exporter, and the following command will create it without a home directory nor the capability of logging in.

sudo useradd --no-create-home --shell /bin/false ipmi-exporter

After that, a folder to contain all exporter files needs to be created. In addition, we will give the newly created user permission to that folder.

sudo mkdir /etc/ipmi-exporter
sudo chown ipmi-exporter:ipmi-exporter /etc/ipmi-exporter/

2. Downloading and testing the exporter.

Clone this repository on your machine, import the exporter required Git repositories, change the functions or exported metrics and compile it with go build.

This will generate an executable, and after successfully testing it with the below-included command (it will output a collection of variables, and among them, there will be ipmi_power_consumption_watts or your defined variables), copy it to the /etc/ipmi-exporter/ folder.

curl localhost:9392/metrics

Note that the 9392 port is used because it was unallocated when this exporter was developed and it generates no conflicts with any other already existing exporter (see this Github page for more information about this and other available ports).

3. Transform this executable into a service.

If the above-included instructions were correctly followed, the steps needed to make this simple exporter run as a service are fairly simple. With your preferred editor, create ipmi-exporter.service file inside the /etc/systemd/system folder and paste the contents of the ipmi-exporter.service file included with this repository. Save and close the file.

After that, execute the following commands.

sudo systemctl daemon-reload
sudo systemctl start ipmi-exporter.service
sudo systemctl status ipmi-exporter.service

If everything worked correctly, the following output should be observed.

● ipmi-exporter.service - IPMI exporter service
   Loaded: loaded (/etc/systemd/system/ipmi-exporter.service; enabled; vendor preset: enabled)
   Active: active (running) since Tue 2019-12-03 08:13:57 UTC; 3h 20min ago
 Main PID: 16808 (ipmi-exporter)
    Tasks: 13 (limit: 4915)
   CGroup: /system.slice/ipmi-exporter.service
           └─16808 /etc/ipmi-exporter/ipmi-exporter/ipmi-exporter


sudo[20762]: ipmi-exporter : TTY=unknown ; PWD=/ ; USER=root ; COMMAND=/usr/sbin/ipmi-sensors -h localhost --no-sensor-type-output...
sudo[20762]: pam_unix(sudo:session): session opened for user root by (uid=0)
sudo[20762]: pam_unix(sudo:session): session closed for user root