about-rego-files.adoc

About Rego files

Validation rules are written in Rego, the Open Policy Agent (OPA) native query language. The rules are stored as .rego files in the /usr/share/opa/policies/io/konveyor/forklift/<provider> directory of the Validation pod.

Each validation rule is defined in a separate .rego file and tests for a specific condition. If the condition evaluates as true, the rule adds a {“category”, “label”, “assessment”} hash to the concerns. The concerns content is added to the concerns key in the inventory record of the VM. The web console displays the content of the concerns key for each VM in the provider inventory.

The following .rego file example checks for distributed resource scheduling enabled in the cluster of a VMware VM:

drs_enabled.rego example

package io.konveyor.forklift.vmware (1)

has_drs_enabled {
    input.host.cluster.drsEnabled (2)
}

concerns[flag] {
    has_drs_enabled
    flag := {
        "category": "Information",
        "label": "VM running in a DRS-enabled cluster",
        "assessment": "Distributed resource scheduling is not currently supported by OpenShift Virtualization. The VM can be migrated but it will not have this feature in the target environment."
    }
}

1. Each validation rule is defined within a package. The package namespaces are io.konveyor.forklift.vmware for VMware and io.konveyor.forklift.ovirt for {rhv-full}.

2. Query parameters are based on the input key of the Validation service JSON.