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Rewrite the project README file to be more succinct and to the point. Add
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Update CHANGELOG file with recent changes.
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4
CHANGELOG.md
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@ -7,6 +7,9 @@ The format is based on [Keep a Changelog], and this project adheres to [Semantic
## [Unreleased]
### Added
- (23e073f) feat: add example systemd service file
- (3911eca) feat: rename output binary and archives
- (f6e328a) feat: correctly handle shutdown signals
- (6e575aa) feat: rewrite cli flags and environment variables
- (0f0efe5) feat: remove startup script from docker image
- (e2902b8) feat: improve logging on startup
@ -18,6 +21,7 @@ The format is based on [Keep a Changelog], and this project adheres to [Semantic
- (93da909) fix: use correct flag in dockerfile ([#18](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/18))
### BREAKING CHANGE
- Release binary name has been changed to `fail2ban_exporter`.
- Replace `--socket` flag with `--collector.f2b.socket`.
- Merge `--port` flag and `--web.listen-address` into a single flag.
- Remove `--collector.textfile` flag, its value is now derived from `--collector.textfile.directory`.

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README.md
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@ -1,44 +1,118 @@
# Fail2Ban Prometheus Exporter
Go tool to collect and export metrics on Fail2Ban
[![Pipeline](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/badges/main/pipeline.svg)](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter)
Collect metrics from a running fail2ban instance.
## Table of Contents
1. Introduction
2. Running the Exporter
3. Running in Docker
4. Metrics
1. Quick Start
2. Metrics
3. Configuration
4. Building from source
5. Textfile metrics
## 1. Introduction
This exporter collects metrics from a running fail2ban instance.
## 1. Quick Start
Once the exporter is running, metrics are available at `localhost:9191/metrics`.
The exporter can be run as a standalone binary or a docker container.
(The default port is `9191` but can be modified with the `--web.listen-address` flag)
### 1.1. Standalone
The exporter communicates with the fail2ban server over its socket.
This allows the data collected by the exporter to always align with the output of the `fail2ban-client`.
The following command will start collecting metrics from the `/var/run/fail2ban/fail2ban.sock` file and expose them on port `9191`.
The default location of the socket is: `/var/run/fail2ban/fail2ban.sock`
```
$ fail2ban_exporter --collector.f2b.socket=/var/run/fail2ban/fail2ban.sock --web.listen-address=":9191"
## 1.1. Grafana
2022/02/20 09:54:06 fail2ban exporter version 0.5.0
2022/02/20 09:54:06 starting server at :9191
2022/02/20 09:54:06 reading metrics from fail2ban socket: /var/run/fail2ban/fail2ban.sock
2022/02/20 09:54:06 metrics available at '/metrics'
2022/02/20 09:54:06 ready
```
The metrics exported by this tool are compatible with Prometheus and Grafana. A sample grafana dashboard can be found in the `grafana.json` file. Just import the contents of this file into a new Grafana dashboard to get started.
Binary files for each release can be found on the [releases](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/releases) page.
### 1.2. Docker
**Docker run**
```
docker run -d \
--name "fail2ban-exporter" \
-v /var/run/fail2ban:/var/run/fail2ban:ro \
-p "9191:9191" \
registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
```
**Docker compose**
```
version: "2"
services:
exporter:
image: registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
volumes:
- /var/run/fail2ban/:/var/run/fail2ban:ro
ports:
- "9191:9191"
```
Use the `:latest` tag to get the latest stable release. Or use the `:nightly` tag for the latest (unstable) version.
See the [registry page](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/container_registry) for all available tags.
**NOTE:** While it is possible to mount the `fail2ban.sock` file directly, it is recommended to mount the parent folder instead.
The `.sock` file is deleted by fail2ban on shutdown and re-created on startup and this causes problems for the docker mount.
See [this reply](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/issues/11#note_665003499) for more details.
## 2. Metrics
The exporter exposes the following metrics:
*All metric names are prefixed with `f2b_`*
| Metric | Description | Example |
|------------------------------|------------------------------------------------------------------------------------|-----------------------------------------------------|
| `up` | Returns 1 if the exporter is up and running | `f2b_up 1` |
| `errors` | Count the number of errors since startup by type | |
| `errors{type="socket_conn"}` | Errors connecting to the fail2ban socket (e.g. connection refused) | `f2b_errors{type="socket_conn"} 0` |
| `errors{type="socket_req"}` | Errors sending requests to the fail2ban server (e.g. invalid responses) | `f2b_errors{type="socket_req"} 0` |
| `jail_count` | Number of jails configured in fail2ban | `f2b_jail_count 2` |
| `jail_banned_current` | Number of IPs currently banned per jail | `f2b_jail_banned_current{jail="sshd"} 15` |
| `jail_banned_total` | Total number of banned IPs since fail2ban startup per jail (includes expired bans) | `f2b_jail_banned_total{jail="sshd"} 31` |
| `jail_failed_current` | Number of current failures per jail | `f2b_jail_failed_current{jail="sshd"} 6` |
| `jail_failed_total` | Total number of failures since fail2ban startup per jail | `f2b_jail_failed_total{jail="sshd"} 125` |
| `jail_config_ban_time` | How long an IP is banned for in this jail (in seconds) | `f2b_config_jail_ban_time{jail="sshd"} 600` |
| `jail_config_find_time` | How far back the filter will look for failures in this jail (in seconds) | `f2b_config_jail_find_time{jail="sshd"} 600` |
| `jail_config_max_retry` | The max number of failures allowed before banning an IP in this jail | `f2b_config_jail_max_retries{jail="sshd"} 5` |
| `version` | Version string of the exporter and fail2ban | `f2b_version{exporter="0.5.0",fail2ban="0.11.1"} 1` |
The metrics above correspond to the matching fields in the `fail2ban-client status <jail>` command:
```
Status for the jail: sshd
|- Filter
| |- Currently failed: 6
| |- Total failed: 125
| `- File list: /var/log/auth.log
`- Actions
|- Currently banned: 15
|- Total banned: 31
`- Banned IP list: ...
```
### 2.1. Grafana
The metrics exported by this tool are compatible with Prometheus and Grafana.
A sample grafana dashboard can be found in the [grafana.json](/examples/grafana/dashboard.json) file.
Just import the contents of this file into a new Grafana dashboard to get started.
*(Sample dashboard is compatible with Grafana `8.3.3` and above)*
## 2. Running the Exporter
## 3. Configuration
The exporter is compiled and released as a single binary.
This makes it very easy to run in any environment.
No additional runtime dependencies are required.
The exporter is configured with CLI flags and environment variables.
There are no configuration files.
Compiled binaries for various platforms are provided in each release.
See the [releases page](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/releases) for more information.
**CLI Usage**
**CLI flags**
```
$ fail2ban-prometheus-exporter -h
usage: fail2ban-prometheus-exporter [<flags>]
usage: fail2ban_exporter [<flags>]
Flags:
-h, --help Show context-sensitive help (also try --help-long and --help-man).
@ -57,175 +131,27 @@ Flags:
**Environment variables**
The tool can also be configured using environment variables. Each CLI parameter has a corresponding environment variable.
Each environment variable corresponds to a CLI flag.
If both are specified, the CLI flag takes precedence.
```
F2B_COLLECTOR_SOCKET
F2B_COLLECTOR_TEXT_PATH
F2B_WEB_LISTEN_ADDRESS
F2B_WEB_BASICAUTH_USER
F2B_WEB_BASICAUTH_PASS
```
| Environment variable | Corresponding CLI flag |
|---------------------------|----------------------------------|
| `F2B_COLLECTOR_SOCKET` | `--collector.f2b.socket` |
| `F2B_COLLECTOR_TEXT_PATH` | `--collector.textfile.directory` |
| `F2B_WEB_LISTEN_ADDRESS` | `--web.listen-address` |
| `F2B_WEB_BASICAUTH_USER` | `--web.basic-auth.username` |
| `F2B_WEB_BASICAUTH_PASS` | `--web.basic-auth.password` |
**Example**
## 4. Building from source
```
fail2ban-prometheus-exporter --collector.f2b.socket=/var/run/fail2ban/fail2ban.sock --web.listen-address=":9191"
```
The simplest way to build the project is to run the `build/snapshot` make command.
This will use `goreleaser` to build out binaries and archives for the project.
Binaries are stored in the `dist/` folder.
Note that the exporter will need read access to the fail2ban socket.
Alternatively, `go mod download` and `go build` can be used from the `src/` folder to build out the project.
This will download dependencies and build the project.
### 2.1. Compile from Source
The code can be compiled from source by running `go build` inside the `src/` folder.
Go version `1.15` or greater is required.
Run `go mod download` to download all necessary dependencies before running the build.
## 3. Running in Docker
An official docker image is available on the Gitlab container registry.
Use it by pulling the following image:
```
registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
```
Use the `:latest` tag to get the latest stable release. Or use the `:nightly` tag for the latest (unstable) version.
See the [registry page](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/container_registry) for all available tags.
### 3.1. Volumes
The docker image is designed to run by mounting the fail2ban run folder.
The run folder should be mounted in the container at: `/var/run/fail2ban`.
The folder can be mounted with read-only (`ro`) permissions.
**NOTE:** While it is possible to mount the `fail2ban.sock` file directly, it is recommended to mount the parent folder instead.
The `.sock` file is deleted by fail2ban on shutdown and re-created on startup and this causes problems for the docker mount.
See [this reply](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/issues/11#note_665003499) for more details.
### 3.2. Docker run
Use the following command to run the exporter as a docker container.
```
docker run -d \
--name "fail2ban-exporter" \
-v /var/run/fail2ban:/var/run/fail2ban:ro \
-p "9191:9191" \
registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
```
### 3.3. Docker compose
The following is a simple docker-compose file to run the exporter.
```
version: "2"
services:
exporter:
image: registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
volumes:
- /var/run/fail2ban/:/var/run/fail2ban:ro
ports:
- "9191:9191"
```
## 4. Metrics
Access exported metrics at the `/metrics` path on the configured port.
**Note on Fail2Ban Jails**
fail2ban can be configured to process different log files and use different rules for each one.
These separate configurations are referred to as *jails*.
For example, fail2ban can be configured to watch the system logs for failed SSH connections and Nextcloud logs for failed logins.
In this configuration, there will be two jails - one for IPs banned from the SSH logs, and one for IPs banned from the Nextcloud logs.
This tool exports several metrics *per jail*, meaning that it is possible to track how many IPs are being banned in each jail as well as the overall total.
This can be useful to track what services are seeing more failed logins.
### 4.1. Fail2Ban Metrics
These are the metrics exported by reading data from the fail2ban server socket.
All metrics are prefixed with `f2b_`.
Exposed metrics:
* `up` - Returns 1 if the fail2ban server is up and connection succeeds
* `errors` - Number of errors since startup
* `socket_conn` - Errors connecting to the fail2ban socket (e.g. connection refused)
* `socket_req` - Errors sending requests to the fail2ban server (e.g. invalid responses)
* `jail_count` - Number of jails configured in fail2ban
* `jail_banned_current` (per jail) - Number of IPs currently banned
* `jail_banned_total` (per jail) - Total number of banned IPs since fail2ban startup (includes expired bans)
* `jail_failed_current` (per jail) - Number of current failures
* `jail_failed_total` (per jail) - Total number of failures since fail2ban startup
* `jail_config_ban_time` (per jail) - How long an IP is banned for in this jail (in seconds)
* `jail_config_find_time` (per jail) - How far back the filter will look for failures in this jail (in seconds)
* `jail_config_max_retry` (per jail) - The max number of failures allowed before banning an IP in this jail
* `version` - Version string of the exporter and fail2ban
**Sample**
```
# HELP f2b_errors Number of errors found since startup
# TYPE f2b_errors counter
f2b_errors{type="socket_conn"} 0
f2b_errors{type="socket_req"} 0
# HELP f2b_jail_banned_current Number of IPs currently banned in this jail
# TYPE f2b_jail_banned_current gauge
f2b_jail_banned_current{jail="recidive"} 5
f2b_jail_banned_current{jail="sshd"} 15
# HELP f2b_jail_banned_total Total number of IPs banned by this jail (includes expired bans)
# TYPE f2b_jail_banned_total gauge
f2b_jail_banned_total{jail="recidive"} 6
f2b_jail_banned_total{jail="sshd"} 31
# HELP f2b_jail_count Number of defined jails
# TYPE f2b_jail_count gauge
f2b_jail_count 2
# HELP f2b_jail_failed_current Number of current failures on this jail's filter
# TYPE f2b_jail_failed_current gauge
f2b_jail_failed_current{jail="recidive"} 5
f2b_jail_failed_current{jail="sshd"} 6
# HELP f2b_jail_failed_total Number of total failures on this jail's filter
# TYPE f2b_jail_failed_total gauge
f2b_jail_failed_total{jail="recidive"} 7
f2b_jail_failed_total{jail="sshd"} 125
# HELP f2b_config_jail_ban_time How long an IP is banned for in this jail (in seconds)
# TYPE f2b_config_jail_ban_time gauge
f2b_config_jail_ban_time{jail="recidive"} 604800
f2b_config_jail_ban_time{jail="sshd"} 600
# HELP f2b_config_jail_find_time How far back will the filter look for failures in this jail (in seconds)
# TYPE f2b_config_jail_find_time gauge
f2b_config_jail_find_time{jail="recidive"} 86400
f2b_config_jail_find_time{jail="sshd"} 600
# HELP f2b_config_jail_max_retries The number of failures allowed until the IP is banned by this jail
# TYPE f2b_config_jail_max_retries gauge
f2b_config_jail_max_retries{jail="recidive"} 5
f2b_config_jail_max_retries{jail="sshd"} 5
# HELP f2b_up Check if the fail2ban server is up
# TYPE f2b_up gauge
f2b_up 1
# HELP f2b_version Version of the exporter and fail2ban server
# TYPE f2b_version gauge
f2b_version{exporter="0.3.0",fail2ban="0.11.1"} 1
```
The metrics above correspond to the matching fields in the `fail2ban-client status <jail>` command:
```
Status for the jail: sshd|- Filter
| |- Currently failed: 6
| |- Total failed: 125
| `- File list: /var/log/auth.log
`- Actions
|- Currently banned: 15
|- Total banned: 31
`- Banned IP list: ...
```
### 4.2. Textfile Metrics
## 5. Textfile metrics
For more flexibility the exporter also allows exporting metrics collected from a text file.

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