Filtering¶

Operations Center uses expr-lang for filtering in various places, including filtering of results fetched from the inventory as well as selection of updates and update files.

See Inventory for more information about filtering inventory results. See Update for more information about update configuration.

Expr is an expression language that uses a Go-like syntax with some more human-readable operators.

Note

For a full list of available functions and examples for more advanced expressions, see the full language definition at https://expr-lang.org/docs/language-definition.

Common Examples¶

Filtering Results from Inventory¶

Expression	Entity	Description
`name != "incusbr0" and name != "meshbr0"`	network	Get all network except the automatically created ones named `incusbr0` and `meshbr0`
`object.config["ipv4.address"] == "10.115.25.1/24"`	network	Get all networks that have the IPv4 address `10.115.25.1/24` configured
`"/1.0/profiles/default" in object.used_by`	network	Get all networks that are used by the `default` profile

Note

Field names of the entities in the inventory are the same as the properties field of the JSON or YAML representation shown over the API or in the operations-center inventory <entity> list -f json command, where <entity> is one of image, instance, network, etc. Use operations-center inventory -h to see the available entities.

Filtering Updates and Update Files¶

If a filter is defined, the filter needs to evaluate to true for the update being fetched by Operations Center and false otherwise. A filter expression resulting in an non boolean value is considered an error. The empty filter expression does not filter at all, same effect as true.

Expression	Description
`"stable" in channels`	Only download updates that are in the `stable` channel
`applies_to_architecture(architecture, "x86_64")`	Only download updates that apply to `x86_64` architecture

Note

Operations Center has the following extended functions for filtering update files:

applies_to_architecture(architecture string, expected_architecture string) – returns true, if the file architecture matches the expected architecture or if the file is architecture neutral.

Note

Field names of updates are the same as the properties field of the JSON or YAML representation shown over the API or in the operations-center provisioning update list -f json command.