OpenVPN Auth Log Exporter

This is a simple Golang application that builds an exporter to be used with Prometheus to get the OpenVPN server authentication logs

Overview

This exporter is designed to expose metrics about a hypothetical service written in Golang. It provides insights into the performance and health of the service by exposing various metrics in the Prometheus exposition format.

Prerequisites

Golang installed on your machine (Installation Guide)
Prometheus server set up and running (Prometheus Installation)

Installation

Clone this repository:

git clone https://github.com/devpolatto/openvpn-auth-log-exporter.git

Navigate to the project directory:
```
cd openvpn-auth-log-exporter
```
Download the dependencies
```
go mod download
```
Build the exporter:
```
go build main .
```

Usage

Run the exporter:
```
./main
```
The script expects the user to indicate where the .log file to be monitored is located. By default, the script searches /go/src/app/ovpn-ldap-auth.log.

To replace the location, run:
```
./main -openvpn.auth_paths /path/to/.log
```
Visit http://localhost:8080/metrics to access the metrics endpoint.
Configure Prometheus to scrape metrics from the exporter by adding the following configuration to your prometheus.yml file:
```
scrape_configs:
  - job_name: 'openvpn-auth-log-exporter'
    static_configs:
      - targets: ['192.168.10.10:9177']
```
We chose to leave the path as /metrics because it is the prometheus default. You can change both the port and the path, as shown below:
```
./main -web.telemetry-path "/logs" -web.listen-address "9172"
```
Restart Prometheus to apply the changes.

Metrics

The exporter displays the following log in the following format:

openvpn_ldap_user_logs_total{DN="",MessageResponse="unable to bind",ResultCode="1",Timestamp="2024-02-05 21:32:06",Username="",action="connection",status="error"} 1

Docker

To build a docker image, run:

cd openvpn-auth-log-exporter

docker build -t openvpn-auth-log-exporter .

Then run the conatiner. Remember to make the volume bind ready for the .log file in your system file

docker run -p 9177:9177 -v ./ovpn-ldap-auth.log:/go/src/app/openvpn-status-auth.log openvpn-exporter:latest