authlog_exporter

Prometheus exporter for collecting metrics from linux auth.log file.

Collected metrics

The client provides a metric authlog_events_total which contains the number of auth events group by event type, user and ip address. Client also could analyze the location of IP addresses found in auth.log if geoIP database is specified.

Metric description

Example metrics:

# HELP authlog_events_total The total number of auth events by user and IP addresses
# TYPE authlog_events_total counter
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="invalidUser",ipAddress="12.123.12.123",user="support"} 1
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="notAllowedUser",ipAddress="12.123.12.123",user="root"} 1
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="notAllowedUser",ipAddress="12.123.123.1",user="root"} 5
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="authAccepted",ipAddress="123.123.12.12",user="testuser"} 2
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="authFailed",ipAddress="123.123.12.12",user="root"} 1
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="authFailed",ipAddress="123.123.12.123",user="root"} 1
authlog_events_total{cityName="",countryName="",countyISOCode="",eventType="connectionClosed",ipAddress="123.123.12.12",user="testuser"} 1

If geoIP database is specified:

# HELP authlog_events_total The total number of auth events by user and IP addresses
# TYPE authlog_events_total counter
authlog_events_total{cityName="",countryName="United States",countyISOCode="US",eventType="invalidUser",ipAddress="12.123.12.123",user="support"} 1
authlog_events_total{cityName="",countryName="United States",countyISOCode="US",eventType="notAllowedUser",ipAddress="12.123.12.123",user="root"} 1
authlog_events_total{cityName="",countryName="United States",countyISOCode="US",eventType="notAllowedUser",ipAddress="12.123.123.1",user="root"} 5
authlog_events_total{cityName="Beijing",countryName="China",countyISOCode="CN",eventType="authAccepted",ipAddress="123.123.12.12",user="testuser"} 2
authlog_events_total{cityName="Beijing",countryName="China",countyISOCode="CN",eventType="authFailed",ipAddress="123.123.12.12",user="root"} 1
authlog_events_total{cityName="Beijing",countryName="China",countyISOCode="CN",eventType="authFailed",ipAddress="123.123.12.123",user="root"} 1
authlog_events_total{cityName="Beijing",countryName="China",countyISOCode="CN",eventType="connectionClosed",ipAddress="123.123.12.12",user="testuser"} 1

Prefix regexp:

^(?P<date>[A-Z][a-z]{2}\\s+\\d{1,2}) (?P<time>(\\d{2}:?){3}) (?P<host>[a-zA-Z0-9_\\-\\.]+) (?P<ident>[a-zA-Z0-9_\\-]+)(\\[(?P<pid>\\d+)\\])?: 

Collecting events:

Event type	Regexp for search event
authAccepted	Accepted (password|publickey) for (?P<user>.*) from (?P<ipAddress>.*) port
authFailed	Failed (password|publickey) for (invalid user )?(?P<user>.*) from (?P<ipAddress>.*) port
invalidUser	Invalid user (?P<user>.*) from (?P<ipAddress>.*) port
notAllowedUser	User (?P<user>.*) from (?P<ipAddress>.*) not allowed because
connectionClosed	Connection closed by authenticating user (?P<user>.*) (?P<ipAddress>.*) port

Getting Started

Building and running

git clone https://github.com/woblerr/authlog_exporter.git
cd authlog_exporter
make build
./authlog_exporter <flags>

By default, metrics will be collecting from /var/log/auth.log and will be available at http://localhost:9991/metrics. This means that the user who runs authlog_exporter should have read permission to file /var/log/auth.log. You can changed log file location by using the--auth.log flag.

For geoIP analyze you need to specify --geo.type flag:

• db - for local geoIP database file,
• url - for geoIP database API.

For local geoIP database usage you also need specify --geo.db flag (path to geoIP database file).

The flag --web.config.file allows to specify the path to the configuration for TLS and/or basic authentication.
The description of TLS configuration and basic authentication can be found at exporter-toolkit/web.

Available configuration flags:

./authlog_exporter --help
usage: authlog_exporter [<flags>]


Flags:
  -h, --[no-]help                Show context-sensitive help (also try --help-long and --help-man).
      --auth.log="/var/log/auth.log"  
                                 Path to auth.log.
      --web.endpoint="/metrics"  Endpoint used for metrics.
      --web.listen-address=:9991 ...  
                                 Addresses on which to expose metrics and web interface. Repeatable for multiple addresses.
      --web.config.file=""       [EXPERIMENTAL] Path to configuration file that can enable TLS or authentication.
      --geo.db=""                Path to geoIP database file.
      --geo.lang="en"            Output language format.
      --geo.timeout=2            Timeout in seconds for waiting response from geoIP database API.
      --geo.type=""              Type of geoIP database: db, url.
      --geo.url="https://reallyfreegeoip.org/json/"  
                                 URL for geoIP database API.
      --[no-]metric.hideip       Set this flag to hide IPs in the output and therefore drastically reduce the amount of metrics
                                 published.
      --[no-]metric.hideuser     Set this flag to hide user accounts in the output and therefore drastically reduce the amount of metrics
                                 published.
      --log.level=info           Only log messages with the given severity or above. One of: [debug, info, warn, error]
      --log.format=logfmt        Output format of log messages. One of: [logfmt, json]

geoIP

Local geoIP database

To analyze IP addresses location found in the log from local geoIP database you need to free download: GeoLite2-City.

The library geoip2-golang is used for reading the GeoLite2 database.

./authlog_exporter --geo.type db --geo.db /path/to/GeoLite2-City.mmdb

Уou can specify output language (default en):

./authlog_exporter --geo.type db --geo.db /path/to/GeoLite2-City.mmdb --geo.lang ru

Metric example:

authlog_events_total{cityName="Пекин",countryName="Китай",countyISOCode="CN",eventType="authAccepted",ipAddress="123.123.12.12",user="testuser"} 2

geoIP database API

To analyze IP addresses location using external API https://reallyfreegeoip.org:

./authlog_exporter --geo.type url

Be aware that API may have a limit of requests per hour. See API documentation.

Running tests

make test

For building and running on test log:

make run-test

Running as systemd service

• Register authlog_exporter (already builded, if not - exec make build before) as a systemd service:

make prepare-service

Validate prepared file authlog_exporter.service and run:

sudo make install-service

• View service logs:

journalctl -u authlog_exporter.service

• Delete systemd service:

sudo make remove-service

---

Manual register systemd service:

cp authlog_exporter.service.template authlog_exporter.service

In file authlog_exporter.service replace /usr/bin to full path to authlog_exporter.

sudo cp authlog_exporter.service /etc/systemd/system/authlog_exporter.service
sudo systemctl daemon-reload
sudo systemctl enable authlog_exporter.service
sudo systemctl restart authlog_exporter.service
systemctl -l status authlog_exporter.service

---

Running as docker container

Be aware that user who runs docker container should have read permission to file /var/log/auth.log. Otherwise, the container won't start.

• Build container:

make docker-build

or manual:

docker build  -f Dockerfile  -t authlog_exporter.

• Run container

make docker-run

or manual:

docker run -d --restart=always \
  --name authlog_exporter \
  -p 9991:9991 \
  -v /var/log/auth.log:/log/auth.log:ro \
  -u $(id -u):$(id -g) \
  authlog_exporter \
  --auth.log /log/auth.log

RPM/DEB packages

You can use the already prepared rpm/deb package to install the exporter. Only the authlog_exporter binary and the service file are installed by package.

For example:

rpm -ql authlog_exporter

/etc/systemd/system/authlog_exporter.service
/usr/bin/authlog_exporter