Thruk Grafana Datasource - a Grafana backend datasource using Thruks REST API

Installation

Search for thruk in the Grafana plugins directory or simply use the grafana-cli command:

%> grafana-cli plugins install sni-thruk-datasource

Also OMD-Labs comes with this datasource included, so if you use OMD-Labs, everything is setup already.

Otherwise follow these steps:

%> cd var/grafana/plugins
%> git clone -b release-1.0.4 https://github.com/sni/grafana-thruk-datasource.git
%> restart grafana

Replace release-1.0.4 with the last available release branch.

Create Datasource

Add a new datasource and select:

Use the Grafana proxy.

• Type 'Thruk'
• Url to Thruk, ex.: 'https://localhost/sitename/thruk'

Table Queries

Using the table panel, you can display most data from the rest api. However only text, numbers and timestamps can be displayed in a sane way. Support for nested data structures is limited.

Select the rest path from where you want to display data. Then choose all columns. Aggregation functions can be added as well and always affect the column following afterwards.

Variable Queries

Thruks rest api can be used to fill grafana variables. For example to get all hosts of a certain hostgroup, use this example query:

SELECT name FROM hosts WHERE groups >= 'linux'

Annotation Queries

Annotation queries can be used to add logfile entries into your graphs. Please note that annotations are shared across all graphs in a dashboard.

It is important to use at least a time filter.

Single Stat Queries

Single stats are best used with REST endpoints which return aggregated values already or use aggregation functions like, avg, sum, min, max or count.

Timeseries based panels

Althouth Thruk isn't a timeseries databases und usually only returns table data, some queries can be converted to fake timeseries if the panel cannot handle table data.

You can either use queries which have 2 columns (name, value) or queries which only return a single result row with numeric values only.

Statistic Data Pie Chart

For example the pie chart plugin can be used with stats queries like this:

SELECT count() state, state FROM /hosts

The query is expected to fetch 2 columns. The first is the value, the second is the name.

Single Host Pie Chart

Ex.: Use statistics data for a single host to put it into a pie chart:

SELECT num_services_ok, num_services_warn, num_services_crit, num_services_unknown FROM /hosts WHERE name = '$name' LIMIT 1

Using Variables

Dashboard variables can be used in almost all queries. For example if you define a dashboard variable named host you can then use $host in your queries.

There is a special syntax for time filter: field = $time which will be replaced by (field >= starttime AND field <= endtime). This can be used to reduce results to the dashboards timeframe.

SELECT time, message FROM /hosts/$host/alerts WHERE time = $time

which is the same as

SELECT time, message FROM /alerts WHERE host_name = "$host" AND time = $time

Development

To test and improve the plugin you can run Grafana instance in Docker using following command (in the source directory of this plugin):

%> make dev

This will start a grafana container and a build watcher which updates the plugin is the dist/ folder.

The dev instance can be accessed at `http://localhost:3000``

Note: You need to add the datasource manually and you need to run "make build" once before starting the dev container, otherwise Grafana won't find the datasource.

Testing

For testing you can use the demo Thruk instance at:

• URL: https://demo.thruk.org/demo/thruk/
• Basic Auth: test / test

Create Release

How to create a new release:

%> export RELVERSION=1.0.7
%> export GRAFANA_ACCESS_POLICY_TOKEN=...
%> vi package.json # replace version
%> vi CHANGELOG.md # add changelog entry
%> git commit -am "Release v${RELVERSION}"
%> git tag -a v${RELVERSION} -m "Create release tag v${RELVERSION}"
%> make GRAFANA_ACCESS_POLICY_TOKEN=${GRAFANA_ACCESS_POLICY_TOKEN} releasebuild
# create release here https://github.com/sni/grafana-thruk-datasource/releases/new
# submit plugin update here https://grafana.com/orgs/sni/plugins

Changelog

see CHANGELOG.md