Lstail

A command line tool to query log events from ElasticSearch, a bit like tail for Logstash/ElasticSearch.

Lstail queries ElasticSearch for log events and displays them on the terminal. Saved Searches from Kibana can be used for quick access to filters and prepared column configuration. For more details and usage examples please see the documentation at https://lstail.org/.

Features

• Follow mode like in tail -f
• CSV output / export
• Can read Saved Searches from ElasticSearch and use their filters and column setup
• Flexible configurable output of columns, colors and padding
• Can be proxied through Kibana if not direct ElasticSearch connection is possible
• Works with ElasticSearch 2.x - 7.x
• Made with Python and love

Installation

Lstail requires Python 3.9 or newer. The easiest method is to install directly from pypi using pip:

pip install lstail

If you prefer, you can download lstail and install it directly from source:

python setup.py install

Get the Source

The source code is available at https://github.com/eht16/lstail/.

Setup

Before using Lstail, you need to create a config file called lstail.conf. Lstail will search for lstail.conf in the following locations (in that order):

• /etc/lstail.conf
• ~/.config/lstail.conf
• lstail.conf (in current working directory)

Alternatively, you can specify the name of the config file to be read using the --config command line parameter.

An example config file can be found in the sources or online at https://raw.githubusercontent.com/eht16/lstail/main/lstail-example.conf. The important part to modify in the config file is the server section which must be edited to point to your ElasticSearch instance to query data from.

For details on all configuration options, please see the documentation: https://lstail.org/.

Usage

Display events (from the configured index pattern) since ten minutes:

lstail -r 10m

Display the last 20 events (from the configured index pattern):

lstail -n 20

Display all events matching the given query:

lstail -q 'host: google.com'

List Saved Searches from Kibana:

lstail -l

Display and follow events using the Saved Search "Syslog" (use Ctrl-C to interrupt):

lstail -s Syslog -f

Overwrite search query for Saved Search "Syslog" (i.e. ignore the query stored in the Saved Search but use the configured columns):

lstail -s Syslog -q program:cron

Command line options

usage: lstail [-h] [-V] [-d] [-v] [-c FILE] [-f] [-l] [-H] [--csv]
              [-n NUM] [-q QUERY] [-r RANGE] [-s NAME] [--select-saved-search]

optional arguments:
  -h, --help            show this help message and exit
  -V, --version         show version and exit (default: False)
  -d, --debug           enable tracebacks (default: False)
  -v, --verbose         Show own log messages (default: False)
  -c FILE, --config FILE
                        configuration file path (default: None)
  -f, --follow          Constantly fetch new data from ElasticSearch (default: False)
  -l, --list-saved-searches
                        List all saved searches from Kibana (default: False)
  -H, --no-header       Do not print header line before the output (default: False)
  --csv                 Use CSV (comma separated) output (default: False)
  -n NUM, --lines NUM   Output the last NUM lines, instead of the last 10 (default: None)
  -q QUERY, --query QUERY
                        Set/Overwrite the search query (use Lucene query syntax) (default: None)
  -r RANGE, --range RANGE
                        Query events from the last RANGE minutes(m)/hours(h)/days(d) (default: None)
  -s NAME, --saved-search NAME
                        Saved search title as stored in Kibana ("-" to select from a list) (default: None)
  --select-saved-search
                        Interactively select a saved search from a list (default: False)

Contributing

Found a bug or got a feature request? Please report it at https://github.com/eht16/lstail/issues.

Author

Enrico Tröger enrico.troeger@uvena.de