0f0efe58af
Update the docker image to remove the `run.sh` script and instead run the exporter directly. This keeps the docker image as simple as possible. Update README file with extra info on how to collect textfile metrics in a docker container. BREAKING CHANGE: Using the textfile collector in docker now requires setting environment variables.
269 lines
10 KiB
Markdown
269 lines
10 KiB
Markdown
# Fail2Ban Prometheus Exporter
|
|
|
|
Go tool to collect and export metrics on Fail2Ban
|
|
|
|
## Table of Contents
|
|
1. Introduction
|
|
2. Running the Exporter
|
|
3. Running in Docker
|
|
4. Metrics
|
|
|
|
## 1. Introduction
|
|
This exporter collects metrics from a running fail2ban instance.
|
|
|
|
Once the exporter is running, metrics are available at `localhost:9191/metrics`.
|
|
|
|
(The default port is `9191` but can be modified with the `--port` flag)
|
|
|
|
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 default location of the socket is: `/var/run/fail2ban/fail2ban.sock`
|
|
|
|
## 1.1. Grafana
|
|
|
|
The metrics exported by this tool are compatible with Prometheus and Grafana. A sample grafana dashboard can be found in the `grafana.json` 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
|
|
|
|
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.
|
|
|
|
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**
|
|
```
|
|
$ fail2ban-prometheus-exporter -h
|
|
usage: exporter [<flags>]
|
|
|
|
Flags:
|
|
-h, --help Show context-sensitive help (also try --help-long and --help-man).
|
|
--version show version info and exit
|
|
--port=9191 port to use for the metrics server
|
|
--web.listen-address="0.0.0.0"
|
|
address to use for the metrics server
|
|
--socket="" path to the fail2ban server socket
|
|
--collector.textfile enable the textfile collector
|
|
--collector.textfile.directory=""
|
|
directory to read text files with metrics from
|
|
--web.basic-auth.username=""
|
|
username to use to protect endpoints with basic auth
|
|
--web.basic-auth.password=""
|
|
password to use to protect endpoints with basic auth
|
|
```
|
|
|
|
**Environment variables**
|
|
|
|
The tool can also be configured using environment variables. Each CLI parameter has a corresponding environment variable.
|
|
|
|
```
|
|
F2B_COLLECTOR_SOCKET
|
|
F2B_COLLECTOR_TEXT
|
|
F2B_COLLECTOR_TEXT_PATH
|
|
F2B_WEB_PORT
|
|
F2B_WEB_LISTEN_ADDRESS
|
|
F2B_WEB_BASICAUTH_USER
|
|
F2B_WEB_BASICAUTH_PASS
|
|
```
|
|
|
|
**Example**
|
|
|
|
```
|
|
fail2ban-prometheus-exporter --socket /var/run/fail2ban/fail2ban.sock --port 9191
|
|
```
|
|
|
|
Note that the exporter will need read access to the fail2ban socket.
|
|
|
|
### 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
|
|
|
|
For more flexibility the exporter also allows exporting metrics collected from a text file.
|
|
|
|
To enable textfile metrics:
|
|
1. Enable the collector with `--collector.textfile=true`
|
|
2. Provide the directory to read files from with the `--collector.textfile.directory` flag
|
|
|
|
Metrics collected from these files will be exposed directly alongside the other metrics without any additional processing.
|
|
This means that it is the responsibility of the file creator to ensure the format is correct.
|
|
|
|
By exporting textfile metrics an extra metric is also exported with an error count for each file:
|
|
|
|
```
|
|
# HELP textfile_error Checks for errors while reading text files
|
|
# TYPE textfile_error gauge
|
|
textfile_error{path="file.prom"} 0
|
|
```
|
|
|
|
**NOTE:** Any file not ending with `.prom` will be ignored.
|
|
|
|
**Running in Docker**
|
|
|
|
To collect textfile metrics inside a docker container, a couple of things need to be done:
|
|
1. Mount the folder with the metrics
|
|
2. Set the relevant environment variables
|
|
|
|
*For example:*
|
|
```
|
|
docker run -d \
|
|
--name "fail2ban-exporter" \
|
|
-v /var/run/fail2ban:/var/run/fail2ban:ro \
|
|
-v /path/to/metrics:/app/metrics/:ro \
|
|
-e F2B_COLLECTOR_TEXT=true \
|
|
-e F2B_COLLECTOR_TEXT_PATH=/app/metrics \
|
|
-p "9191:9191" \
|
|
registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
|
|
```
|