docs: update changelog for release

Remove deprecated database metric collector

See merge request hectorjsmith/fail2ban-prometheus-exporter!50

.gitlab-ci.yml

@@ -1,21 +1,26 @@
 image: golang:latest
 
 before_script:
-  - make install-deps
+  - make go/dependencies
 
 stages:
   - test
   - build
 
+dependencies:
+  stage: test
+  script:
+    - make go/checkDependencies
+
 format:
   stage: test
   script:
-    - make format
+    - make go/checkFmt
 
 test:
   stage: test
   script:
-    - make test
+    - make go/test
 
 build:
   stage: build
@@ -31,7 +36,7 @@ build:
       - dist/checksums.txt
     expire_in: 1 day
 
-docker-gitlab:
+docker/gitlab:
   stage: build
   only:
     - main
@@ -44,6 +49,6 @@ docker-gitlab:
     - apk add make
     - docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
   script:
-    - make docker/build-latest
+    - make docker/build/latest
-    - make docker/build-tag
+    - make docker/build/tag
     - docker push registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter

.goreleaser.yml

@@ -2,13 +2,12 @@
 # Make sure to check the documentation at http://goreleaser.com
 before:
   hooks:
-    - make install-deps
+    - make go/dependencies
 builds:
   -
     dir: src
     goos:
       - linux
-      - windows
       - darwin
     goarch:
       - amd64

CHANGELOG.md

@@ -4,7 +4,61 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog], and this project adheres to [Semantic Versioning].
 
-## [Unreleased]## [0.1.0] - 2021-03-28
+## [Unreleased]
+*Nothing yet*
+
+## [0.5.0] - 2021-12-21
+*Remove deprecated code & support python2*
+
+### Added
+- (b397a51) feat: sample grafana dashboard ([#15](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/15))
+- (c208c8e) feat: add listen address parameter - thanks [@private-creator](https://gitlab.com/private-creator)!
+
+### Fixed
+- (7932ccb) fix: support python2 fail2ban ([#14](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/14)) - thanks [@private-creator](https://gitlab.com/private-creator)!
+
+### BREAKING CHANGE
+- Remove `-db` CLI flag
+- Remove `f2b_errors{type="db"}` metric
+
+## [0.4.0] - 2021-10-18
+*Add new fail2ban config metrics*
+
+### Added
+- (56730c8) feat: add new jail config metrics
+- (5a107cc) feat: support for textfile metrics ([#13](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/13))
+
+### Removed
+- (b268f86) remove: database-based metrics
+- (0b6a941) remove: windows builds
+
+## [0.3.0] - 2021-09-27
+*Export new version metrics ([#12](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/12))*
+
+### Added
+- (3c9a005) feat: render basic html page at root url
+- (22a165d) feat: improve startup logging
+- (fba9ee2) feat: export new version metric ([#12](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/12))
+
+## [0.2.0] - 2021-08-31
+*Collect metrics through fail2ban socket - based on [#11](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/11)*
+
+### Added
+- (39133d0) feat: collect new up metric from fail2ban socket
+- (4da46f3) feat: export metrics with socket errors
+- (bd841c3) feat: set up metric to 0 if errors found
+- (1964dde) feat: export metrics for failed/banned counts
+- (2ab1f7d) feat: support reading fail2ban socket in docker
+- (1282d63) feat: new metric for enabled jails ([#1](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/1))
+
+### Fixed
+- (526b1c7) fix: update banned metrics to exclude expired bans ([#11](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/11))
+
+### Deprecated
+- Use of the fail2ban database has been deprecated. The exporter now collects metrics through the fail2ban socket file. See [#11](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/-/issues/11) for more details.
+
+## [0.1.0] - 2021-03-28
+*Initial release*
 
 ### Added
 - (6355c9e) feat: fail on startup if database file does not exist ([#8](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/issues/8))
@@ -18,13 +72,16 @@ The format is based on [Keep a Changelog], and this project adheres to [Semantic
 ### Fixed
 - (0842419) fix: compile tool without cgo_enabled flag
 
+## 0.0.0 - 2021-02-05
+*Repository creation*
 
 ---
 
-*This changelog is automatically generated by [git-chglog]*
-
 [Keep a Changelog]: https://keepachangelog.com/en/1.0.0/
 [Semantic Versioning]: https://semver.org/spec/v2.0.0.html
-[git-chglog]: https://github.com/git-chglog/git-chglog
 [Unreleased]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.1.0...main
 [0.1.0]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.0.0...0.1.0
+[0.2.0]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.1.0...0.2.0
+[0.3.0]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.2.0...0.3.0
+[0.4.0]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.3.0...0.4.0
+[0.5.0]: https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/compare/0.4.0...0.5.0

Makefile

@@ -1,21 +1,23 @@
-install-deps:
+go/dependencies:
 	cd src/ && go mod download
 
-# Standard go test
-test:
-	cd src/ && go test ./... -v -race
-
 # Make sure no unnecessary dependencies are present
-go-mod-tidy:
+go/checkDependencies:
 	cd src/ && go mod tidy -v
 	git diff-index --quiet HEAD
 
-format:
+# Standard go test
-	cd src/ && go fmt $(go list ./... | grep -v /vendor/)
+go/test:
-	cd src/ && go vet $(go list ./... | grep -v /vendor/)
+	cd src/ && go test ./... -v -race
 
-generateChangelog:
+go/fmt:
-	./tools/git-chglog_linux_amd64 --config tools/chglog/config.yml 0.0.0.. > CHANGELOG.md
+	cd src/ && go fmt ./...
+
+go/checkFmt:
+	test -z $(shell gofmt -l .)
+
+docs/genChangelog:
+	./tools/git-chglog_linux_amd64 --config tools/chglog/config.yml 0.0.0.. > CHANGELOG_gen.md
 
 build/snapshot:
 	./tools/goreleaser_linux_amd64 --snapshot --rm-dist --skip-publish
@@ -27,8 +29,8 @@ build/docker:
 	cd src/ && go build -o exporter \
      -ldflags '-X main.version=$(shell git describe --tags) -X main.commit=${shell git rev-parse HEAD} -X "main.date=${shell date --rfc-3339=seconds}" -X main.builtBy=docker' exporter.go
 
-docker/build-latest:
+docker/build/latest:
 	docker build -t registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest .
 
-docker/build-tag:
+docker/build/tag:
 	docker build -t registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:$(shell git describe --tags) .

README.md

@@ -3,36 +3,72 @@
 Go tool to collect and export metrics on Fail2Ban
 
 ## Table of Contents
-1. How to use
+1. Introduction
-2. Docker
+2. Running the Exporter
-    1. Volumes
+3. Running in Docker
-    2. Docker run
-    3. Docker compose
-3. CLI usage
 4. Metrics
 
-## 1. How to use
+## 1. Introduction
+This exporter collects metrics from a running fail2ban instance.
 
-Run the exporter by providing it with a fail2ban database to read data from.
-Read access to the database is required.
 Once the exporter is running, metrics are available at `localhost:9191/metrics`.
 
-The default port is `9191`, but this can be modified with the `-port` flag.
+(The default port is `9191` but can be modified with the `-port` flag)
 
-**Note:** By default fail2ban stores the database file at: `/var/lib/fail2ban/fail2ban.sqlite3`
+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`.
 
-**Fail2Ban Jails**
+The default location of the socket is: `/var/run/fail2ban/fail2ban.sock`
 
-fail2ban can be configured to process different log files and use different rules for each one.
+## 1.1. Grafana
-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.
+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.
-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.
+*(Sample dashboard is compatible with Grafana `8.2.1` and above)*
-This can be useful to track what services are seeing more failed logins.
 
-## 2. Docker
+## 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.
+
+**Usage**
+```
+$ fail2ban-prometheus-exporter -h
+
+  -web.listen-address string
+        address to use for metrics server (default 0.0.0.0)
+  -port int
+        port to use for the metrics server (default 9191)
+  -socket string
+        path to the fail2ban server socket
+  -version
+        show version info and exit
+  -collector.textfile
+        enable the textfile collector
+  -collector.textfile.directory string
+        directory to read text files with metrics from
+```
+
+**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:
@@ -44,26 +80,30 @@ registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
 Use the `:latest` tag to get the most up to date code (less stable) or use one of the version tagged images to use a specific release.
 See the [registry page](https://gitlab.com/hectorjsmith/fail2ban-prometheus-exporter/container_registry) for all available tags.
 
-### 2.1. Volumes
+### 3.1. Volumes
 
-The docker image is designed to run by mounting the fail2ban sqlite3 database.
+The docker image is designed to run by mounting the fail2ban run folder.
-The database should be mounted at: `/app/fail2ban.sqlite3`
+The run folder should be mounted in the container at: `/var/run/fail2ban`.
 
-The database can be mounted with read-only permissions.
+The folder can be mounted with read-only (`ro`) permissions.
 
-### 2.2. Docker run
+**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.
 
-Use the following command to run the forwarder as a docker container.
+### 3.2. Docker run
+
+Use the following command to run the exporter as a docker container.
 
 ```
 docker run -d \
     --name "fail2ban-exporter" \
-    -v /var/lib/fail2ban/fail2ban.sqlite3:/app/fail2ban.sqlite3:ro \
+    -v /var/run/fail2ban:/var/run/fail2ban:ro \
-    -p "9191:9191"
+    -p "9191:9191" \
     registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
 ```
 
-### 2.3. Docker compose
+### 3.3. Docker compose
 
 The following is a simple docker-compose file to run the exporter.
 
@@ -73,51 +113,121 @@ services:
   exporter:
     image: registry.gitlab.com/hectorjsmith/fail2ban-prometheus-exporter:latest
     volumes:
-    - /var/lib/fail2ban/fail2ban.sqlite3:/app/fail2ban.sqlite3:ro
+    - /var/run/fail2ban/:/var/run/fail2ban:ro
     ports:
     - "9191:9191"
 ```
 
-## 3. CLI usage
-
-```
-$ fail2ban-prometheus-exporter -h
-
-  -db string
-        path to the fail2ban sqlite database
-  -port int
-        port to use for the metrics server (default 9191)
-  -version
-        show version info and exit
-```
-
 ## 4. Metrics
 
-Access exported metrics at `/metrics` (on the provided port).
+Access exported metrics at the `/metrics` path on the configured port.
 
-**Note:** All metric names include the `fail2ban_` prefix to make sure they are unique and easier to find.
+**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 service is up
+* `up` - Returns 1 if the fail2ban server is up and connection succeeds
-* `bad_ips` (per jail)
+* `errors` - Number of errors since startup
-    * A *bad IP* is defined as an IP that has been banned at least once in the past
+    * `socket_conn` - Errors connecting to the fail2ban socket (e.g. connection refused)
-    * Bad IPs are counted per jail
+    * `socket_req` - Errors sending requests to the fail2ban server (e.g. invalid responses)
-* `banned_ips` (per jail)
+* `jail_count` - Number of jails configured in fail2ban
-    * A *banned IP* is defined as an IP that is currently banned on the firewall
+* `jail_banned_current` (per jail) - Number of IPs currently banned
-    * Banned IPs are counted per jail
+* `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 fail2ban_bad_ips Number of bad IPs stored in the database (per jail).
+# HELP f2b_errors Number of errors found since startup
-# TYPE fail2ban_bad_ips gauge
+# TYPE f2b_errors counter
-fail2ban_bad_ips{jail="jail1"} 6
+f2b_errors{type="socket_conn"} 0
-fail2ban_bad_ips{jail="jail2"} 8
+f2b_errors{type="socket_req"} 0
-# HELP fail2ban_banned_ips Number of banned IPs stored in the database (per jail).
+# HELP f2b_jail_banned_current Number of IPs currently banned in this jail
-# TYPE fail2ban_banned_ips gauge
+# TYPE f2b_jail_banned_current gauge
-fail2ban_banned_ips{jail="jail1"} 3
+f2b_jail_banned_current{jail="recidive"} 5
-fail2ban_banned_ips{jail="jail2"} 2
+f2b_jail_banned_current{jail="sshd"} 15
-# HELP fail2ban_up Was the last fail2ban query successful.
+# HELP f2b_jail_banned_total Total number of IPs banned by this jail (includes expired bans)
-# TYPE fail2ban_up gauge
+# TYPE f2b_jail_banned_total gauge
-fail2ban_up 1
+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.

docker/run.sh

@@ -3,7 +3,18 @@
 # Print version to logs for debugging purposes
 /app/fail2ban-prometheus-exporter -version
 
+socket_path=/var/run/fail2ban/fail2ban.sock
+textfile_dir=/app/textfile/
+textfile_enabled=false
+
+# Enable textfile metrics if the folder exists (i.e. was mounted by docker)
+if [ -d $textfile_dir ]; then
+    textfile_enabled=true
+fi
+
 # Start the exporter (use exec to support graceful shutdown)
 # Inspired by: https://akomljen.com/stopping-docker-containers-gracefully/
 exec /app/fail2ban-prometheus-exporter \
-    -db /app/fail2ban.sqlite3
+    -socket "$socket_path" \
+    -collector.textfile=$textfile_enabled \
+    -collector.textfile.directory="$textfile_dir"

grafana.json

@@ -0,0 +1,718 @@
+{
+  "__inputs": [],
+  "__requires": [
+    {
+      "type": "grafana",
+      "id": "grafana",
+      "name": "Grafana",
+      "version": "8.2.1"
+    },
+    {
+      "type": "panel",
+      "id": "table",
+      "name": "Table",
+      "version": ""
+    },
+    {
+      "type": "panel",
+      "id": "timeseries",
+      "name": "Time series",
+      "version": ""
+    }
+  ],
+  "annotations": {
+    "list": [
+      {
+        "builtIn": 1,
+        "datasource": "-- Grafana --",
+        "enable": true,
+        "hide": true,
+        "iconColor": "rgba(0, 211, 255, 1)",
+        "name": "Annotations & Alerts",
+        "target": {
+          "limit": 100,
+          "matchAny": false,
+          "tags": [],
+          "type": "dashboard"
+        },
+        "type": "dashboard"
+      }
+    ]
+  },
+  "editable": true,
+  "fiscalYearStartMonth": 0,
+  "gnetId": null,
+  "graphTooltip": 2,
+  "id": null,
+  "links": [],
+  "liveNow": false,
+  "panels": [
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "thresholds"
+          },
+          "custom": {
+            "align": "auto",
+            "displayMode": "auto"
+          },
+          "mappings": [],
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          }
+        },
+        "overrides": [
+          {
+            "matcher": {
+              "id": "byRegexp",
+              "options": ".*Time"
+            },
+            "properties": [
+              {
+                "id": "unit",
+                "value": "s"
+              }
+            ]
+          }
+        ]
+      },
+      "gridPos": {
+        "h": 6,
+        "w": 24,
+        "x": 0,
+        "y": 0
+      },
+      "id": 206,
+      "options": {
+        "showHeader": true
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_config_jail_max_retries",
+          "format": "table",
+          "instant": true,
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "A"
+        },
+        {
+          "exemplar": true,
+          "expr": "f2b_config_jail_ban_time",
+          "format": "table",
+          "hide": false,
+          "instant": true,
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "B"
+        },
+        {
+          "exemplar": true,
+          "expr": "f2b_config_jail_find_time",
+          "format": "table",
+          "hide": false,
+          "instant": true,
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "C"
+        }
+      ],
+      "title": "F2B Config",
+      "transformations": [
+        {
+          "id": "merge",
+          "options": {}
+        },
+        {
+          "id": "groupBy",
+          "options": {
+            "fields": {
+              "Value #A": {
+                "aggregations": [
+                  "lastNotNull"
+                ],
+                "operation": "aggregate"
+              },
+              "Value #B": {
+                "aggregations": [
+                  "lastNotNull"
+                ],
+                "operation": "aggregate"
+              },
+              "Value #C": {
+                "aggregations": [
+                  "lastNotNull"
+                ],
+                "operation": "aggregate"
+              },
+              "jail": {
+                "aggregations": [],
+                "operation": "groupby"
+              }
+            }
+          }
+        },
+        {
+          "id": "organize",
+          "options": {
+            "excludeByName": {},
+            "indexByName": {},
+            "renameByName": {
+              "Value #A (lastNotNull)": "Max Retries",
+              "Value #B (lastNotNull)": "Ban Time",
+              "Value #C (lastNotNull)": "Find Time",
+              "jail": "Jail"
+            }
+          }
+        }
+      ],
+      "transparent": true,
+      "type": "table"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 6
+      },
+      "id": 190,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_jail_failed_total",
+          "hide": false,
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Failures (Total)",
+      "transparent": true,
+      "type": "timeseries"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 6
+      },
+      "id": 191,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_jail_banned_total",
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Bans (Total)",
+      "transparent": true,
+      "type": "timeseries"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 0,
+        "y": 14
+      },
+      "id": 208,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_jail_failed_current",
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Failures (Current)",
+      "transparent": true,
+      "type": "timeseries"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 8,
+        "w": 12,
+        "x": 12,
+        "y": 14
+      },
+      "id": 209,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_jail_banned_current",
+          "interval": "",
+          "legendFormat": "{{jail}}",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Bans (Current)",
+      "transparent": true,
+      "type": "timeseries"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "max": 1,
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 5,
+        "w": 12,
+        "x": 0,
+        "y": 22
+      },
+      "id": 203,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_up",
+          "interval": "",
+          "legendFormat": "Up",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Up",
+      "transparent": true,
+      "type": "timeseries"
+    },
+    {
+      "datasource": null,
+      "description": "",
+      "fieldConfig": {
+        "defaults": {
+          "color": {
+            "mode": "palette-classic"
+          },
+          "custom": {
+            "axisLabel": "",
+            "axisPlacement": "auto",
+            "barAlignment": 0,
+            "drawStyle": "line",
+            "fillOpacity": 10,
+            "gradientMode": "none",
+            "hideFrom": {
+              "legend": false,
+              "tooltip": false,
+              "viz": false
+            },
+            "lineInterpolation": "linear",
+            "lineWidth": 1,
+            "pointSize": 5,
+            "scaleDistribution": {
+              "type": "linear"
+            },
+            "showPoints": "never",
+            "spanNulls": true,
+            "stacking": {
+              "group": "A",
+              "mode": "none"
+            },
+            "thresholdsStyle": {
+              "mode": "off"
+            }
+          },
+          "mappings": [],
+          "max": 1,
+          "min": 0,
+          "thresholds": {
+            "mode": "absolute",
+            "steps": [
+              {
+                "color": "green",
+                "value": null
+              }
+            ]
+          },
+          "unit": "short"
+        },
+        "overrides": []
+      },
+      "gridPos": {
+        "h": 5,
+        "w": 12,
+        "x": 12,
+        "y": 22
+      },
+      "id": 204,
+      "options": {
+        "legend": {
+          "calcs": [
+            "lastNotNull"
+          ],
+          "displayMode": "table",
+          "placement": "right"
+        },
+        "tooltip": {
+          "mode": "single"
+        }
+      },
+      "pluginVersion": "8.2.1",
+      "targets": [
+        {
+          "exemplar": true,
+          "expr": "f2b_errors",
+          "interval": "",
+          "legendFormat": "{{type}}",
+          "refId": "A"
+        }
+      ],
+      "timeFrom": null,
+      "timeShift": null,
+      "title": "Fail2Ban Exporter Errors",
+      "transparent": true,
+      "type": "timeseries"
+    }
+  ],
+  "refresh": "30s",
+  "schemaVersion": 31,
+  "style": "dark",
+  "tags": [],
+  "templating": {
+    "list": []
+  },
+  "time": {
+    "from": "now-6h",
+    "to": "now"
+  },
+  "timepicker": {},
+  "timezone": "",
+  "title": "F2B",
+  "uid": "cTkH9AT7z",
+  "version": 13
+}

src/cfg/cfg.go

@@ -12,16 +12,22 @@ const (
 )
 
 type AppSettings struct {
-	VersionMode    bool
+	VersionMode          bool
-	MetricsPort    int
+	MetricsAddress       string
-	Fail2BanDbPath string
+	MetricsPort          int
+	Fail2BanSocketPath   string
+	FileCollectorPath    string
+	FileCollectorEnabled bool
 }
 
 func Parse() *AppSettings {
 	appSettings := &AppSettings{}
 	flag.BoolVar(&appSettings.VersionMode, "version", false, "show version info and exit")
+	flag.StringVar(&appSettings.MetricsAddress, "web.listen-address", "0.0.0.0", "address to use for the metrics server")
 	flag.IntVar(&appSettings.MetricsPort, "port", 9191, "port to use for the metrics server")
-	flag.StringVar(&appSettings.Fail2BanDbPath, "db", "", "path to the fail2ban sqlite database")
+	flag.StringVar(&appSettings.Fail2BanSocketPath, "socket", "", "path to the fail2ban server socket")
+	flag.BoolVar(&appSettings.FileCollectorEnabled, "collector.textfile", false, "enable the textfile collector")
+	flag.StringVar(&appSettings.FileCollectorPath, "collector.textfile.directory", "", "directory to read text files with metrics from")
 
 	flag.Parse()
 	appSettings.validateFlags()
@@ -31,8 +37,8 @@ func Parse() *AppSettings {
 func (settings *AppSettings) validateFlags() {
 	var flagsValid = true
 	if !settings.VersionMode {
-		if settings.Fail2BanDbPath == "" {
+		if settings.Fail2BanSocketPath == "" {
-			fmt.Println("missing flag 'db'")
+			fmt.Println("fail2ban socket path must not be blank")
 			flagsValid = false
 		}
 		if settings.MetricsPort < minServerPort || settings.MetricsPort > maxServerPort {
@@ -40,6 +46,10 @@ func (settings *AppSettings) validateFlags() {
 				minServerPort, maxServerPort, settings.MetricsPort)
 			flagsValid = false
 		}
+		if settings.FileCollectorEnabled && settings.FileCollectorPath == "" {
+			fmt.Printf("file collector directory path must not be empty if collector enabled\n")
+			flagsValid = false
+		}
 	}
 	if !flagsValid {
 		flag.Usage()

src/collector/f2b/collector.go

@@ -0,0 +1,53 @@
+package f2b
+
+import (
+	"fail2ban-prometheus-exporter/cfg"
+	"fail2ban-prometheus-exporter/socket"
+	"github.com/prometheus/client_golang/prometheus"
+	"log"
+)
+
+type Collector struct {
+	socketPath                 string
+	exporterVersion            string
+	lastError                  error
+	socketConnectionErrorCount int
+	socketRequestErrorCount    int
+}
+
+func NewExporter(appSettings *cfg.AppSettings, exporterVersion string) *Collector {
+	return &Collector{
+		socketPath:                 appSettings.Fail2BanSocketPath,
+		exporterVersion:            exporterVersion,
+		lastError:                  nil,
+		socketConnectionErrorCount: 0,
+		socketRequestErrorCount:    0,
+	}
+}
+
+func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+	ch <- metricServerUp
+	ch <- metricJailCount
+	ch <- metricJailFailedCurrent
+	ch <- metricJailFailedTotal
+	ch <- metricJailBannedCurrent
+	ch <- metricJailBannedTotal
+	ch <- metricErrorCount
+}
+
+func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+	s, err := socket.ConnectToSocket(c.socketPath)
+	if err != nil {
+		log.Printf("error opening socket: %v", err)
+		c.socketConnectionErrorCount++
+	} else {
+		defer s.Close()
+	}
+
+	c.collectServerUpMetric(ch, s)
+	if err == nil && s != nil {
+		c.collectJailMetrics(ch, s)
+		c.collectVersionMetric(ch, s)
+	}
+	c.collectErrorCountMetric(ch)
+}

src/collector/f2b/socket.go

@@ -0,0 +1,179 @@
+package f2b
+
+import (
+	"fail2ban-prometheus-exporter/socket"
+	"github.com/prometheus/client_golang/prometheus"
+	"log"
+)
+
+const (
+	namespace = "f2b"
+)
+
+var (
+	metricErrorCount = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "errors"),
+		"Number of errors found since startup",
+		[]string{"type"}, nil,
+	)
+	metricServerUp = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "up"),
+		"Check if the fail2ban server is up",
+		nil, nil,
+	)
+	metricJailCount = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "jail_count"),
+		"Number of defined jails",
+		nil, nil,
+	)
+	metricJailFailedCurrent = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "jail_failed_current"),
+		"Number of current failures on this jail's filter",
+		[]string{"jail"}, nil,
+	)
+	metricJailFailedTotal = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "jail_failed_total"),
+		"Number of total failures on this jail's filter",
+		[]string{"jail"}, nil,
+	)
+	metricJailBannedCurrent = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "jail_banned_current"),
+		"Number of IPs currently banned in this jail",
+		[]string{"jail"}, nil,
+	)
+	metricJailBannedTotal = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "jail_banned_total"),
+		"Total number of IPs banned by this jail (includes expired bans)",
+		[]string{"jail"}, nil,
+	)
+	metricJailBanTime = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_ban_time"),
+		"How long an IP is banned for in this jail (in seconds)",
+		[]string{"jail"}, nil,
+	)
+	metricJailFindTime = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_find_time"),
+		"How far back will the filter look for failures in this jail (in seconds)",
+		[]string{"jail"}, nil,
+	)
+	metricJailMaxRetry = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "config", "jail_max_retries"),
+		"The number of failures allowed until the IP is banned by this jail",
+		[]string{"jail"}, nil,
+	)
+	metricVersionInfo = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "version"),
+		"Version of the exporter and fail2ban server",
+		[]string{"exporter", "fail2ban"}, nil,
+	)
+)
+
+func (c *Collector) collectErrorCountMetric(ch chan<- prometheus.Metric) {
+	ch <- prometheus.MustNewConstMetric(
+		metricErrorCount, prometheus.CounterValue, float64(c.socketConnectionErrorCount), "socket_conn",
+	)
+	ch <- prometheus.MustNewConstMetric(
+		metricErrorCount, prometheus.CounterValue, float64(c.socketRequestErrorCount), "socket_req",
+	)
+}
+
+func (c *Collector) collectServerUpMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+	var serverUp float64 = 0
+	if s != nil {
+		pingSuccess, err := s.Ping()
+		if err != nil {
+			c.socketRequestErrorCount++
+			log.Print(err)
+		}
+		if err == nil && pingSuccess {
+			serverUp = 1
+		}
+	}
+	ch <- prometheus.MustNewConstMetric(
+		metricServerUp, prometheus.GaugeValue, serverUp,
+	)
+}
+
+func (c *Collector) collectJailMetrics(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+	jails, err := s.GetJails()
+	var count float64 = 0
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Print(err)
+	}
+	if err == nil {
+		count = float64(len(jails))
+	}
+	ch <- prometheus.MustNewConstMetric(
+		metricJailCount, prometheus.GaugeValue, count,
+	)
+
+	for i := range jails {
+		c.collectJailStatsMetric(ch, s, jails[i])
+		c.collectJailConfigMetrics(ch, s, jails[i])
+	}
+}
+
+func (c *Collector) collectJailStatsMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket, jail string) {
+	stats, err := s.GetJailStats(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get stats for jail %s: %v", jail, err)
+		return
+	}
+
+	ch <- prometheus.MustNewConstMetric(
+		metricJailFailedCurrent, prometheus.GaugeValue, float64(stats.FailedCurrent), jail,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		metricJailFailedTotal, prometheus.GaugeValue, float64(stats.FailedTotal), jail,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		metricJailBannedCurrent, prometheus.GaugeValue, float64(stats.BannedCurrent), jail,
+	)
+	ch <- prometheus.MustNewConstMetric(
+		metricJailBannedTotal, prometheus.GaugeValue, float64(stats.BannedTotal), jail,
+	)
+}
+
+func (c *Collector) collectJailConfigMetrics(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket, jail string) {
+	banTime, err := s.GetJailBanTime(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get ban time for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailBanTime, prometheus.GaugeValue, float64(banTime), jail,
+		)
+	}
+	findTime, err := s.GetJailFindTime(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get find time for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailFindTime, prometheus.GaugeValue, float64(findTime), jail,
+		)
+	}
+	maxRetry, err := s.GetJailMaxRetries(jail)
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get max retries for jail %s: %v", jail, err)
+	} else {
+		ch <- prometheus.MustNewConstMetric(
+			metricJailMaxRetry, prometheus.GaugeValue, float64(maxRetry), jail,
+		)
+	}
+}
+
+func (c *Collector) collectVersionMetric(ch chan<- prometheus.Metric, s *socket.Fail2BanSocket) {
+	fail2banVersion, err := s.GetServerVersion()
+	if err != nil {
+		c.socketRequestErrorCount++
+		log.Printf("failed to get fail2ban server version: %v", err)
+	}
+
+	ch <- prometheus.MustNewConstMetric(
+		metricVersionInfo, prometheus.GaugeValue, float64(1), c.exporterVersion, fail2banVersion,
+	)
+}

src/collector/textfile/collector.go

@@ -0,0 +1,48 @@
+package textfile
+
+import (
+	"fail2ban-prometheus-exporter/cfg"
+	"github.com/prometheus/client_golang/prometheus"
+	"log"
+)
+
+type Collector struct {
+	enabled    bool
+	folderPath string
+	fileMap    map[string]*fileData
+}
+
+type fileData struct {
+	readErrors   int
+	fileName     string
+	fileContents []byte
+}
+
+func NewCollector(appSettings *cfg.AppSettings) *Collector {
+	collector := &Collector{
+		enabled:    appSettings.FileCollectorEnabled,
+		folderPath: appSettings.FileCollectorPath,
+		fileMap:    make(map[string]*fileData),
+	}
+	if collector.enabled {
+		log.Printf("collector.textfile directory: %s", collector.folderPath)
+	}
+	return collector
+}
+
+func (c *Collector) Describe(ch chan<- *prometheus.Desc) {
+	if c.enabled {
+		ch <- metricReadError
+	}
+}
+
+func (c *Collector) Collect(ch chan<- prometheus.Metric) {
+	if c.enabled {
+		c.collectFileContents()
+		c.collectFileErrors(ch)
+	}
+}
+
+func (c *Collector) appendErrorForPath(path string) {
+	c.fileMap[path].readErrors++
+}

src/collector/textfile/file.go

@@ -0,0 +1,55 @@
+package textfile
+
+import (
+	"github.com/prometheus/client_golang/prometheus"
+	"io/ioutil"
+	"log"
+	"path/filepath"
+	"strings"
+)
+
+const namespace = "textfile"
+
+var (
+	metricReadError = prometheus.NewDesc(
+		prometheus.BuildFQName(namespace, "", "error"),
+		"Checks for errors while reading text files",
+		[]string{"path"}, nil,
+	)
+)
+
+func (c *Collector) collectFileContents() {
+	files, err := ioutil.ReadDir(c.folderPath)
+	if err != nil {
+		log.Printf("error reading directory '%s': %v", c.folderPath, err)
+		return
+	}
+
+	for _, file := range files {
+		fileName := file.Name()
+		if !strings.HasSuffix(strings.ToLower(fileName), ".prom") {
+			continue
+		}
+		c.fileMap[fileName] = &fileData{
+			readErrors: 0,
+			fileName:   fileName,
+		}
+
+		fullPath := filepath.Join(c.folderPath, fileName)
+		content, err := ioutil.ReadFile(fullPath)
+		if err != nil {
+			c.appendErrorForPath(fileName)
+			log.Printf("error reading contents of file '%s': %v", fileName, err)
+		}
+
+		c.fileMap[fileName].fileContents = content
+	}
+}
+
+func (c *Collector) collectFileErrors(ch chan<- prometheus.Metric) {
+	for _, f := range c.fileMap {
+		ch <- prometheus.MustNewConstMetric(
+			metricReadError, prometheus.GaugeValue, float64(f.readErrors), f.fileName,
+		)
+	}
+}

src/collector/textfile/writer.go

@@ -0,0 +1,20 @@
+package textfile
+
+import (
+	"log"
+	"net/http"
+)
+
+func (c *Collector) WriteTextFileMetrics(w http.ResponseWriter, r *http.Request) {
+	if !c.enabled {
+		return
+	}
+
+	for _, f := range c.fileMap {
+		_, err := w.Write(f.fileContents)
+		if err != nil {
+			c.appendErrorForPath(f.fileName)
+			log.Printf("error writing file contents to response writer '%s': %v", f.fileName, err)
+		}
+	}
+}

src/db/db.go

@@ -1,79 +0,0 @@
-package db
-
-import (
-	"database/sql"
-	"log"
-	"os"
-)
-
-const queryBadIpsPerJail = "SELECT j.name, (SELECT COUNT(1) FROM bips b WHERE j.name = b.jail) FROM jails j"
-const queryBannedIpsPerJail = "SELECT j.name, (SELECT COUNT(1) FROM bans b WHERE j.name = b.jail) FROM jails j"
-
-type Fail2BanDB struct {
-	DatabasePath string
-	sqliteDB     *sql.DB
-}
-
-func MustConnectToDb(databasePath string) *Fail2BanDB {
-	if _, err := os.Stat(databasePath); os.IsNotExist(err) {
-		log.Fatalf("database path does not exist: %v", err)
-	}
-	db, err := sql.Open("sqlite3", databasePath)
-	if err != nil {
-		log.Fatal(err)
-	}
-	return &Fail2BanDB{
-		DatabasePath: databasePath,
-		sqliteDB:     db,
-	}
-}
-
-func (db *Fail2BanDB) CountBannedIpsPerJail() (map[string]int, error) {
-	return db.RunJailNameToCountQuery(queryBannedIpsPerJail)
-}
-
-func (db *Fail2BanDB) CountBadIpsPerJail() (map[string]int, error) {
-	return db.RunJailNameToCountQuery(queryBadIpsPerJail)
-}
-
-func (db *Fail2BanDB) RunJailNameToCountQuery(query string) (map[string]int, error) {
-	stmt, err := db.sqliteDB.Prepare(query)
-	defer db.mustCloseStatement(stmt)
-
-	if err != nil {
-		return nil, err
-	}
-
-	jailNameToCountMap := map[string]int{}
-	rows, err := stmt.Query()
-	if err != nil {
-		return nil, err
-	}
-	if rows == nil {
-		return jailNameToCountMap, nil
-	}
-
-	for rows.Next() {
-		if rows.Err() != nil {
-			return nil, err
-		}
-		jailName := ""
-		count := 0
-		err = rows.Scan(&jailName, &count)
-		if err != nil {
-			return nil, err
-		}
-
-		jailNameToCountMap[jailName] = count
-	}
-	return jailNameToCountMap, nil
-}
-
-func (db *Fail2BanDB) mustCloseStatement(stmt *sql.Stmt) {
-	if stmt != nil {
-		err := stmt.Close()
-		if err != nil {
-			log.Fatal(err)
-		}
-	}
-}

src/exporter.go

@@ -2,102 +2,80 @@ package main
 
 import (
 	"fail2ban-prometheus-exporter/cfg"
-	fail2banDb "fail2ban-prometheus-exporter/db"
+	"fail2ban-prometheus-exporter/collector/f2b"
+	"fail2ban-prometheus-exporter/collector/textfile"
 	"fmt"
-	_ "github.com/mattn/go-sqlite3"
-	"github.com/prometheus/client_golang/prometheus"
-	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"log"
 	"net/http"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
-const namespace = "fail2ban"
+const (
+	metricsPath = "/metrics"
+)
 
 var (
 	version = "dev"
 	commit  = "none"
 	date    = "unknown"
 	builtBy = "unknown"
-
-	metricUp = prometheus.NewDesc(
-		prometheus.BuildFQName(namespace, "", "up"),
-		"Was the last fail2ban query successful.",
-		nil, nil,
-	)
-	metricBannedIpsPerJail = prometheus.NewDesc(
-		prometheus.BuildFQName(namespace, "", "banned_ips"),
-		"Number of banned IPs stored in the database (per jail).",
-		[]string{"jail"}, nil,
-	)
-	metricBadIpsPerJail = prometheus.NewDesc(
-		prometheus.BuildFQName(namespace, "", "bad_ips"),
-		"Number of bad IPs stored in the database (per jail).",
-		[]string{"jail"}, nil,
-	)
 )
 
-type Exporter struct {
-	db *fail2banDb.Fail2BanDB
-}
-
-func (e *Exporter) Describe(ch chan<- *prometheus.Desc) {
-	ch <- metricUp
-	ch <- metricBadIpsPerJail
-	ch <- metricBannedIpsPerJail
-}
-
-func (e *Exporter) Collect(ch chan<- prometheus.Metric) {
-	ch <- prometheus.MustNewConstMetric(
-		metricUp, prometheus.GaugeValue, 1,
-	)
-	e.collectBadIpsPerJailMetrics(ch)
-	e.collectBannedIpsPerJailMetrics(ch)
-}
-
-func (e *Exporter) collectBadIpsPerJailMetrics(ch chan<- prometheus.Metric) {
-	jailNameToCountMap, err := e.db.CountBadIpsPerJail()
-	if err != nil {
-		log.Print(err)
-	}
-
-	for jailName, count := range jailNameToCountMap {
-		ch <- prometheus.MustNewConstMetric(
-			metricBadIpsPerJail, prometheus.GaugeValue, float64(count), jailName,
-		)
-	}
-}
-
-func (e *Exporter) collectBannedIpsPerJailMetrics(ch chan<- prometheus.Metric) {
-	jailNameToCountMap, err := e.db.CountBannedIpsPerJail()
-	if err != nil {
-		log.Print(err)
-	}
-
-	for jailName, count := range jailNameToCountMap {
-		ch <- prometheus.MustNewConstMetric(
-			metricBannedIpsPerJail, prometheus.GaugeValue, float64(count), jailName,
-		)
-	}
-}
-
 func printAppVersion() {
 	fmt.Println(version)
 	fmt.Printf("    build date:  %s\r\n    commit hash: %s\r\n    built by:    %s\r\n", date, commit, builtBy)
 }
 
+func rootHtmlHandler(w http.ResponseWriter, r *http.Request) {
+	_, err := w.Write([]byte(
+		`<html>
+			<head><title>Fail2Ban Exporter</title></head>
+			<body>
+			<h1>Fail2Ban Exporter</h1>
+			<p><a href="` + metricsPath + `">Metrics</a></p>
+			</body>
+		</html>`))
+	if err != nil {
+		log.Printf("error handling root url: %v", err)
+		w.WriteHeader(http.StatusInternalServerError)
+	}
+}
+
+func metricHandler(w http.ResponseWriter, r *http.Request, collector *textfile.Collector) {
+	promhttp.Handler().ServeHTTP(w, r)
+	collector.WriteTextFileMetrics(w, r)
+}
+
 func main() {
 	appSettings := cfg.Parse()
 	if appSettings.VersionMode {
 		printAppVersion()
 	} else {
-		log.Print("starting fail2ban exporter")
+		addr := fmt.Sprintf("%s:%d", appSettings.MetricsAddress, appSettings.MetricsPort)
 
-		exporter := &Exporter{
+		log.Printf("starting fail2ban exporter at %s", addr)
-			db: fail2banDb.MustConnectToDb(appSettings.Fail2BanDbPath),
-		}
-		prometheus.MustRegister(exporter)
 
-		http.Handle("/metrics", promhttp.Handler())
+		f2bCollector := f2b.NewExporter(appSettings, version)
-		log.Fatal(http.ListenAndServe(fmt.Sprintf(":%d", appSettings.MetricsPort), nil))
+		prometheus.MustRegister(f2bCollector)
+
+		textFileCollector := textfile.NewCollector(appSettings)
+		prometheus.MustRegister(textFileCollector)
+
+		http.HandleFunc("/", rootHtmlHandler)
+		http.HandleFunc(metricsPath, func(w http.ResponseWriter, r *http.Request) {
+			metricHandler(w, r, textFileCollector)
+		})
+		log.Printf("metrics available at '%s'", metricsPath)
+
+		svrErr := make(chan error)
+		go func() {
+			svrErr <- http.ListenAndServe(addr, nil)
+		}()
+		log.Print("ready")
+
+		err := <-svrErr
+		log.Print(err)
 	}
 }

src/go.mod

@@ -3,6 +3,7 @@ module fail2ban-prometheus-exporter
 go 1.15
 
 require (
-	github.com/mattn/go-sqlite3 v1.14.6
+	github.com/kisielk/og-rek v1.1.0
+	github.com/nlpodyssey/gopickle v0.1.0
 	github.com/prometheus/client_golang v1.9.0
 )

src/go.sum

@@ -137,6 +137,8 @@ github.com/julienschmidt/httprouter v1.2.0/go.mod h1:SYymIcj16QtmaHHD7aYtjjsJG7V
 github.com/julienschmidt/httprouter v1.3.0/go.mod h1:JR6WtHb+2LUe8TCKY3cZOxFyyO8IZAc4RVcycCCAKdM=
 github.com/kisielk/errcheck v1.1.0/go.mod h1:EZBBE59ingxPouuu3KfxchcWSUPOHkagtvWXihfKN4Q=
 github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+oQHNcck=
+github.com/kisielk/og-rek v1.1.0 h1:u10TvQbPtrlY/6H4+BiFsBywwSVTGFsx0YOVtpx3IbI=
+github.com/kisielk/og-rek v1.1.0/go.mod h1:6ihsOSzSAxR/65S3Bn9zNihoEqRquhDQZ2c6I2+MG3c=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/kr/logfmt v0.0.0-20140226030751-b84e30acd515/go.mod h1:+0opPa2QZZtGFBFZlji/RkVcI2GknAs/DXo4wKdlNEc=
@@ -150,8 +152,6 @@ github.com/mattn/go-colorable v0.0.9/go.mod h1:9vuHe8Xs5qXnSaW/c/ABM9alt+Vo+STaO
 github.com/mattn/go-isatty v0.0.3/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-isatty v0.0.4/go.mod h1:M+lRXTBqGeGNdLjl/ufCoiOlB5xdOkqRJdNxMWT7Zi4=
 github.com/mattn/go-runewidth v0.0.2/go.mod h1:LwmH8dsx7+W8Uxz3IHJYH5QSwggIsqBzpuz5H//U1FU=
-github.com/mattn/go-sqlite3 v1.14.6 h1:dNPt6NO46WmLVt2DLNpwczCmdV5boIZ6g/tlDrlRUbg=
-github.com/mattn/go-sqlite3 v1.14.6/go.mod h1:NyWgC/yNuGj7Q9rpYnZvas74GogHl5/Z4A/KQRfk6bU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1 h1:4hp9jkHxhMHkqkrB3Ix0jegS5sx/RkqARlsWZ6pIwiU=
 github.com/matttproud/golang_protobuf_extensions v1.0.1/go.mod h1:D8He9yQNgCq6Z5Ld7szi9bcBfOoFv/3dc6xSMkL2PC0=
 github.com/miekg/dns v1.0.14/go.mod h1:W1PPwlIAgtquWBMBEV9nkV9Cazfe8ScdGz/Lj7v3Nrg=
@@ -175,6 +175,8 @@ github.com/nats-io/nats.go v1.9.1/go.mod h1:ZjDU1L/7fJ09jvUSRVBR2e7+RnLiiIQyqyzE
 github.com/nats-io/nkeys v0.1.0/go.mod h1:xpnFELMwJABBLVhffcfd1MZx6VsNRFpEugbxziKVo7w=
 github.com/nats-io/nkeys v0.1.3/go.mod h1:xpnFELMwJABBLVhffcfd1MZx6VsNRFpEugbxziKVo7w=
 github.com/nats-io/nuid v1.0.1/go.mod h1:19wcPz3Ph3q0Jbyiqsd0kePYG7A95tJPxeL+1OSON2c=
+github.com/nlpodyssey/gopickle v0.1.0 h1:9wjwRqXsOSYWZl4c4ko472b6RW+VB1I441ZcfFg1r5g=
+github.com/nlpodyssey/gopickle v0.1.0/go.mod h1:YIUwjJ2O7+vnBsxUN+MHAAI3N+adqEGiw+nDpwW95bY=
 github.com/oklog/oklog v0.3.2/go.mod h1:FCV+B7mhrz4o+ueLpx+KqkyXRGMWOYEvfiXtdGtbWGs=
 github.com/oklog/run v1.0.0/go.mod h1:dlhp/R75TPv97u0XWUtDeV/lRKWPKSdTuV0TZvrmrQA=
 github.com/olekukonko/tablewriter v0.0.0-20170122224234-a0225b3f23b5/go.mod h1:vsDQFd/mU46D+Z4whnwzcISnGGzXWMclvtLoiIKAKIo=

src/socket/decoder.go

@@ -0,0 +1,8 @@
+package socket
+
+// Py_builtins_str is used by the pickle decoder to parse the server response into a format Go can understand
+type Py_builtins_str struct{}
+
+func (c Py_builtins_str) Call(args ...interface{}) (interface{}, error) {
+	return args[0], nil
+}

src/socket/fail2banSocket.go

@@ -0,0 +1,179 @@
+package socket
+
+import (
+	"fmt"
+	"github.com/kisielk/og-rek"
+	"github.com/nlpodyssey/gopickle/types"
+	"net"
+	"strings"
+)
+
+type Fail2BanSocket struct {
+	socket  net.Conn
+	encoder *ogórek.Encoder
+}
+
+type JailStats struct {
+	FailedCurrent int
+	FailedTotal   int
+	BannedCurrent int
+	BannedTotal   int
+}
+
+func ConnectToSocket(path string) (*Fail2BanSocket, error) {
+	c, err := net.Dial("unix", path)
+	if err != nil {
+		return nil, err
+	}
+	return &Fail2BanSocket{
+		socket:  c,
+		encoder: ogórek.NewEncoder(c),
+	}, nil
+}
+
+func (s *Fail2BanSocket) Close() error {
+	return s.socket.Close()
+}
+
+func (s *Fail2BanSocket) Ping() (bool, error) {
+	response, err := s.sendCommand([]string{pingCommand, "100"})
+	if err != nil {
+		return false, newConnectionError(pingCommand, err)
+	}
+
+	if t, ok := response.(*types.Tuple); ok {
+		if (*t)[1] == "pong" {
+			return true, nil
+		}
+		return false, fmt.Errorf("unexpected response data (expecting 'pong'): %s", (*t)[1])
+	}
+	return false, newBadFormatError(pingCommand, response)
+}
+
+func (s *Fail2BanSocket) GetJails() ([]string, error) {
+	response, err := s.sendCommand([]string{statusCommand})
+	if err != nil {
+		return nil, err
+	}
+
+	if lvl1, ok := response.(*types.Tuple); ok {
+		if lvl2, ok := lvl1.Get(1).(*types.List); ok {
+			if lvl3, ok := lvl2.Get(1).(*types.Tuple); ok {
+				if lvl4, ok := lvl3.Get(1).(string); ok {
+					splitJails := strings.Split(lvl4, ",")
+					return trimSpaceForAll(splitJails), nil
+				}
+			}
+		}
+	}
+	return nil, newBadFormatError(statusCommand, response)
+}
+
+func (s *Fail2BanSocket) GetJailStats(jail string) (JailStats, error) {
+	response, err := s.sendCommand([]string{statusCommand, jail})
+	if err != nil {
+		return JailStats{}, err
+	}
+
+	stats := JailStats{
+		FailedCurrent: -1,
+		FailedTotal:   -1,
+		BannedCurrent: -1,
+		BannedTotal:   -1,
+	}
+
+	if lvl1, ok := response.(*types.Tuple); ok {
+		if lvl2, ok := lvl1.Get(1).(*types.List); ok {
+			if filter, ok := lvl2.Get(0).(*types.Tuple); ok {
+				if filterLvl1, ok := filter.Get(1).(*types.List); ok {
+					if filterCurrentTuple, ok := filterLvl1.Get(0).(*types.Tuple); ok {
+						if filterCurrent, ok := filterCurrentTuple.Get(1).(int); ok {
+							stats.FailedCurrent = filterCurrent
+						}
+					}
+					if filterTotalTuple, ok := filterLvl1.Get(1).(*types.Tuple); ok {
+						if filterTotal, ok := filterTotalTuple.Get(1).(int); ok {
+							stats.FailedTotal = filterTotal
+						}
+					}
+				}
+			}
+			if actions, ok := lvl2.Get(1).(*types.Tuple); ok {
+				if actionsLvl1, ok := actions.Get(1).(*types.List); ok {
+					if actionsCurrentTuple, ok := actionsLvl1.Get(0).(*types.Tuple); ok {
+						if actionsCurrent, ok := actionsCurrentTuple.Get(1).(int); ok {
+							stats.BannedCurrent = actionsCurrent
+						}
+					}
+					if actionsTotalTuple, ok := actionsLvl1.Get(1).(*types.Tuple); ok {
+						if actionsTotal, ok := actionsTotalTuple.Get(1).(int); ok {
+							stats.BannedTotal = actionsTotal
+						}
+					}
+				}
+			}
+			return stats, nil
+		}
+	}
+	return stats, newBadFormatError(statusCommand, response)
+}
+
+func (s *Fail2BanSocket) GetJailBanTime(jail string) (int, error) {
+	command := fmt.Sprintf(banTimeCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
+func (s *Fail2BanSocket) GetJailFindTime(jail string) (int, error) {
+	command := fmt.Sprintf(findTimeCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
+func (s *Fail2BanSocket) GetJailMaxRetries(jail string) (int, error) {
+	command := fmt.Sprintf(maxRetriesCommandFmt, jail)
+	return s.sendSimpleIntCommand(command)
+}
+
+func (s *Fail2BanSocket) GetServerVersion() (string, error) {
+	response, err := s.sendCommand([]string{versionCommand})
+	if err != nil {
+		return "", err
+	}
+
+	if lvl1, ok := response.(*types.Tuple); ok {
+		if versionStr, ok := lvl1.Get(1).(string); ok {
+			return versionStr, nil
+		}
+	}
+	return "", newBadFormatError(versionCommand, response)
+}
+
+// sendSimpleIntCommand sends a command to the fail2ban socket and parses the response to extract an int.
+// This command assumes that the response data is in the format of `(d, d)` where `d` is a number.
+func (s *Fail2BanSocket) sendSimpleIntCommand(command string) (int, error) {
+	response, err := s.sendCommand(strings.Split(command, " "))
+	if err != nil {
+		return -1, err
+	}
+
+	if lvl1, ok := response.(*types.Tuple); ok {
+		if banTime, ok := lvl1.Get(1).(int); ok {
+			return banTime, nil
+		}
+	}
+	return -1, newBadFormatError(command, response)
+}
+
+func newBadFormatError(command string, data interface{}) error {
+	return fmt.Errorf("(%s) unexpected response format - cannot parse: %v", command, data)
+}
+
+func newConnectionError(command string, err error) error {
+	return fmt.Errorf("(%s) failed to send command through socket: %v", command, err)
+}
+
+func trimSpaceForAll(slice []string) []string {
+	for i := range slice {
+		slice[i] = strings.TrimSpace(slice[i])
+	}
+	return slice
+}

src/socket/protocol.go

@@ -0,0 +1,69 @@
+package socket
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"github.com/nlpodyssey/gopickle/pickle"
+)
+
+const (
+	commandTerminator    = "<F2B_END_COMMAND>"
+	pingCommand          = "ping"
+	statusCommand        = "status"
+	versionCommand       = "version"
+	banTimeCommandFmt    = "get %s bantime"
+	findTimeCommandFmt   = "get %s findtime"
+	maxRetriesCommandFmt = "get %s maxretry"
+	socketReadBufferSize = 1024
+)
+
+func (s *Fail2BanSocket) sendCommand(command []string) (interface{}, error) {
+	err := s.write(command)
+	if err != nil {
+		return nil, err
+	}
+	return s.read()
+}
+
+func (s *Fail2BanSocket) write(command []string) error {
+	err := s.encoder.Encode(command)
+	if err != nil {
+		return err
+	}
+	_, err = s.socket.Write([]byte(commandTerminator))
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (s *Fail2BanSocket) read() (interface{}, error) {
+	reader := bufio.NewReader(s.socket)
+
+	data := []byte{}
+	for {
+		buf := make([]byte, socketReadBufferSize)
+		_, err := reader.Read(buf)
+		if err != nil {
+			return nil, err
+		}
+		data = append(data, buf...)
+		containsTerminator := bytes.Contains(data, []byte(commandTerminator))
+		if containsTerminator {
+			break
+		}
+	}
+
+	bufReader := bytes.NewReader(data)
+	unpickler := pickle.NewUnpickler(bufReader)
+
+	unpickler.FindClass = func(module, name string) (interface{}, error) {
+		if (module == "builtins" || module == "__builtin__") && name == "str" {
+			return &Py_builtins_str{}, nil
+		}
+		return nil, fmt.Errorf("class not found: " + module + " : " + name)
+	}
+
+	return unpickler.Load()
+}