Skip to content

Variable Types

This page describes the types of variables, their use cases, and the configuration required for each type.

OpenObserve supports the following variable types:

1. Query Values

This variable dynamically fetches values from a selected field in a stream. It supports both single-select and multi-select options.

When to use: When the available values depend on data already ingested, such as identifiers, names, or categories.

Use Case: Filter the dashboard panels by Pod name using values from logs.

Query variable

Configuration

Basic:

  • Type of Variable: Query Values
  • Name: pod
  • Label (optional): Pod
  • Stream Type: Logs
  • Stream: default
  • Field: k8s_pod_name
  • Default Max Record Size (optional): 20

Advanced:

  • Allow multiple selection: Enabled
  • By Default Select: First value
  • Hide on Dashboard: Disabled
  • Escape Single Quotes: Disabled

Result:

  • This configuration allows users to dynamically select one or more Kubernetes pod names from the logs stream to apply that selection across dashboard panels.
  • The variable dropdown will display up to 20 pod names retrieved from the k8s_pod_name field in the default log stream. These values are based on the most recently ingested records.
  • The multi-selection option is enabled. Users can select more than one value, and all dashboard panels using $pod will update accordingly.

Note

Dropdown menu on the dashboard populated with live values from the data.

2. Constant

This variable allows you to set a fixed value that cannot be changed by dashboard users. The constant variables are shown on the dashboard as plain text.

When to use: When the value should always stay the same and must not be changed by anyone using the dashboard.

Use case: Building a dashboard that focuses only on logs from a specific Kubernetes namespace named ziox. Constant variable

Configuration

Basic:

  • Type of variable: Constant
  • Name: constant-ziox
  • Label (optional): Namespace-name-ziox-constant
  • Value: ziox

Advanced:

  • Hide on Dashboard: Disabled
  • Escape Single Quotes: Disabled

Result:

  • After saving, this variable always uses ziox as the namespace value during query execution. Users cannot modify it from the dashboard interface.
  • All queries referencing $constant-ziox will consistently apply the ziox namespace filter.

3. Textbox

This variable provides a free-form text input field on the dashboard.

When to use: When users need to manually enter a value that may not exist in the dropdown, such as custom IDs or strings.

Use Case: You want users to manually enter the cluster name they want to filter logs by. Textbox variable

Configuration

Basic:

  • Type of variable: Textbox
  • Name: input-cluster-name
  • Label (optional): Enter Cluster Name
  • Default value (optional): _o2_all_

Advanced:

  • Hide On Dashboard: Disabled
  • Escape Single Quotes: Disabled

Result:

  • Users will see a text input field labeled Enter Cluster Name on the dashboard.
  • The default value is _o2_all_, but users can replace it with any cluster name, such as prod or dev, at runtime.
  • All queries using $input-cluster-name will include the user-provided input when executed.

What is _o2_all_?

  • _o2_all_ is a special keyword used to match all values during query execution.
  • If this is set as the default value, the dashboard will include data from all clusters unless the user enters a specific one.

Notes

  • No validation is performed on the input. The value is passed directly into the query.
  • To match all values, users must enter exactly _o2_all_. Writing ALL, all, or <ALL> will not match all values.

4. Custom

This variable lets you predefine a list of selectable values.

When to use: When values are known in advance and should not be fetched from data.

Use Case: You want to allow users to select a predefined service from a list, such as openobserve or ingress-nginx. This is useful when the possible values are known and limited, and you want to control what the user can select. Custom variable

Configuration

Basic:

  • Type of variable: Custom
  • Name: service-name

  • Label (optional): Service Name

    • Label: openobserve
    • Value: openobserve
    • Default: Checked

  • Label: ingress-nginx

    • Value: ingress-nginx
    • Default: Unchecked

Advanced:

  • Allow multiple selection: Disabled
  • Hide on Dashboard: Disabled
  • Escape Single Quotes: Disabled

Result:

  • Users will see a dropdown named Service Name with the default selection set to openobserve.
  • They can switch to ingress-nginx if needed. The multiple selection option is disabled, so only one option can be selected.
  • All queries using $service-name will include the selected value when executed.

Note

  • One value must be selected as the default.
  • Labels are shown on the dashboard, while values are used in the query.
  • The values are injected into queries as-is. No validation or transformation is applied.

Next Steps