Loki data source
Grafana Loki is a set of components that can be combined into a fully featured logging stack. Unlike other logging systems, Loki is built around the idea of only indexing metadata about your logs: labels (just like Prometheus labels). Log data itself is then compressed and stored in chunks in object stores such as S3 or GCS, or even locally on a filesystem.
The following guides will help you get started with Loki:
- Getting started with Loki
- Install Loki
- Loki best practices
- Configure the Loki data source
- LogQL
- Loki query editor
Supported Loki versions
This data source supports these versions of Loki:
- v2.8+
Adding a data source
For instructions on how to add a data source to Grafana, refer to the administration documentation Only users with the organization administrator role can add data sources. Administrators can also configure the data source via YAML with Grafana’s provisioning system.
Once you’ve added the Loki data source, you can configure it so that your Grafana instance’s users can create queries in its query editor when they build dashboards, use Explore, and annotate visualizations.
Note
To troubleshoot configuration and other issues, check the log file located at/var/log/grafana/grafana.log
on Unix systems, or in<grafana_install_dir>/data/log
on other platforms and manual installations.
Provision the data source
You can define and configure the data source in YAML files as part of Grafana’s provisioning system. For more information about provisioning, and for available configuration options, refer to Provisioning Grafana.
Provisioning examples
apiVersion: 1
datasources:
- name: Loki
type: loki
access: proxy
url: http://localhost:3100
jsonData:
timeout: 60
maxLines: 1000
Using basic authorization and a derived field:
You must escape the dollar ($
) character in YAML values because it can be used to interpolate environment variables:
apiVersion: 1
datasources:
- name: Loki
type: loki
access: proxy
url: http://localhost:3100
basicAuth: true
basicAuthUser: my_user
jsonData:
maxLines: 1000
derivedFields:
# Field with internal link pointing to data source in Grafana.
# datasourceUid value can be anything, but it should be unique across all defined data source uids.
- datasourceUid: my_jaeger_uid
matcherRegex: "traceID=(\\w+)"
name: TraceID
# url will be interpreted as query for the datasource
url: '$${__value.raw}'
# optional for URL Label to set a custom display label for the link.
urlDisplayLabel: 'View Trace'
# Field with external link.
- matcherRegex: "traceID=(\\w+)"
name: TraceID
url: 'http://localhost:16686/trace/$${__value.raw}'
secureJsonData:
basicAuthPassword: test_password
Using a Jaeger data source:
In this example, the Jaeger data source’s uid
value should match the Loki data source’s datasourceUid
value.
datasources:
- name: Jaeger
type: jaeger
url: http://jaeger-tracing-query:16686/
access: proxy
# UID should match the datasourceUid in derivedFields.
uid: my_jaeger_uid
Query the data source
The Loki data source’s query editor helps you create log and metric queries that use Loki’s query language, LogQL.
For details, refer to the query editor documentation.
Use template variables
Instead of hard-coding details such as server, application, and sensor names in metric queries, you can use variables. Grafana lists these variables in dropdown select boxes at the top of the dashboard to help you change the data displayed in your dashboard. Grafana refers to such variables as template variables.
For details, see the template variables documentation.