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Chapter 6. Advanced migration options

6.1. Changing precopy intervals for warm migration

You can change the snapshot interval by patching the ForkliftController custom resource (CR).

Procedure

  • Patch the ForkliftController CR:

    $ oc patch forkliftcontroller/<forklift-controller> -n openshift-mtv -p '{"spec": {"controller_precopy_interval": <60>}}' --type=merge 1
    1
    Specify the precopy interval in minutes. The default value is 60.

    You do not need to restart the forklift-controller pod.

6.2. Creating custom rules for the Validation service

The Validation service uses Open Policy Agent (OPA) policy rules to check the suitability of each virtual machine (VM) for migration. The Validation service generates a list of concerns for each VM, which are stored in the Provider Inventory service as VM attributes. The web console displays the concerns for each VM in the provider inventory.

You can create custom rules to extend the default ruleset of the Validation service. For example, you can create a rule that checks whether a VM has multiple disks.

6.2.1. 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 Red Hat Virtualization.
2
Query parameters are based on the input key of the Validation service JSON.

6.2.2. Checking the default validation rules

Before you create a custom rule, you must check the default rules of the Validation service to ensure that you do not create a rule that redefines an existing default value.

Example: If a default rule contains the line default valid_input = false and you create a custom rule that contains the line default valid_input = true, the Validation service will not start.

Procedure

  1. Connect to the terminal of the Validation pod:

    $ oc rsh <validation_pod>
  2. Go to the OPA policies directory for your provider:

    $ cd /usr/share/opa/policies/io/konveyor/forklift/<provider> 1
    1
    Specify vmware or ovirt.
  3. Search for the default policies:

    $ grep -R "default" *

6.2.3. Retrieving the Inventory service JSON

You retrieve the Inventory service JSON by sending an Inventory service query to a virtual machine (VM). The output contains an "input" key, which contains the inventory attributes that are queried by the Validation service rules.

You can create a validation rule based on any attribute in the "input" key, for example, input.snapshot.kind.

Procedure

  1. Retrieve the Inventory service route:

    $ oc get route <inventory_service> -n openshift-mtv
  2. Retrieve the UUID of a provider:

    $ GET https://<inventory_service_route>/providers/<provider> 1
    1
    Allowed values for the provider are vsphere and ovirt.
  3. Retrieve the VMs of a provider:

    $ GET https://<inventory_service_route>/providers/<provider>/<UUID>/vms
  4. Retrieve the details of a VM:

    $ GET https://<inventory_service_route>/providers/<provider>/<UUID>/workloads/<vm>

    Example output

    {
        "input": {
            "selfLink": "providers/vsphere/c872d364-d62b-46f0-bd42-16799f40324e/workloads/vm-431",
            "id": "vm-431",
            "parent": {
                "kind": "Folder",
                "id": "group-v22"
            },
            "revision": 1,
            "name": "iscsi-target",
            "revisionValidated": 1,
            "isTemplate": false,
            "networks": [
                {
                    "kind": "Network",
                    "id": "network-31"
                },
                {
                    "kind": "Network",
                    "id": "network-33"
                }
            ],
            "disks": [
                {
                    "key": 2000,
                    "file": "[iSCSI_Datastore] iscsi-target/iscsi-target-000001.vmdk",
                    "datastore": {
                        "kind": "Datastore",
                        "id": "datastore-63"
                    },
                    "capacity": 17179869184,
                    "shared": false,
                    "rdm": false
                },
                {
                    "key": 2001,
                    "file": "[iSCSI_Datastore] iscsi-target/iscsi-target_1-000001.vmdk",
                    "datastore": {
                        "kind": "Datastore",
                        "id": "datastore-63"
                    },
                    "capacity": 10737418240,
                    "shared": false,
                    "rdm": false
                }
            ],
            "concerns": [],
            "policyVersion": 5,
            "uuid": "42256329-8c3a-2a82-54fd-01d845a8bf49",
            "firmware": "bios",
            "powerState": "poweredOn",
            "connectionState": "connected",
            "snapshot": {
                "kind": "VirtualMachineSnapshot",
                "id": "snapshot-3034"
            },
            "changeTrackingEnabled": false,
            "cpuAffinity": [
                0,
                2
            ],
            "cpuHotAddEnabled": true,
            "cpuHotRemoveEnabled": false,
            "memoryHotAddEnabled": false,
            "faultToleranceEnabled": false,
            "cpuCount": 2,
            "coresPerSocket": 1,
            "memoryMB": 2048,
            "guestName": "Red Hat Enterprise Linux 7 (64-bit)",
            "balloonedMemory": 0,
            "ipAddress": "10.19.2.96",
            "storageUsed": 30436770129,
            "numaNodeAffinity": [
                "0",
                "1"
            ],
            "devices": [
                {
                    "kind": "RealUSBController"
                }
            ],
            "host": {
                "id": "host-29",
                "parent": {
                    "kind": "Cluster",
                    "id": "domain-c26"
                },
                "revision": 1,
                "name": "IP address or host name of the vCenter host or {rhv-short} Engine host",
                "selfLink": "providers/vsphere/c872d364-d62b-46f0-bd42-16799f40324e/hosts/host-29",
                "status": "green",
                "inMaintenance": false,
                "managementServerIp": "10.19.2.96",
                "thumbprint": <thumbprint>,
                "timezone": "UTC",
                "cpuSockets": 2,
                "cpuCores": 16,
                "productName": "VMware ESXi",
                "productVersion": "6.5.0",
                "networking": {
                    "pNICs": [
                        {
                            "key": "key-vim.host.PhysicalNic-vmnic0",
                            "linkSpeed": 10000
                        },
                        {
                            "key": "key-vim.host.PhysicalNic-vmnic1",
                            "linkSpeed": 10000
                        },
                        {
                            "key": "key-vim.host.PhysicalNic-vmnic2",
                            "linkSpeed": 10000
                        },
                        {
                            "key": "key-vim.host.PhysicalNic-vmnic3",
                            "linkSpeed": 10000
                        }
                    ],
                    "vNICs": [
                        {
                            "key": "key-vim.host.VirtualNic-vmk2",
                            "portGroup": "VM_Migration",
                            "dPortGroup": "",
                            "ipAddress": "192.168.79.13",
                            "subnetMask": "255.255.255.0",
                            "mtu": 9000
                        },
                        {
                            "key": "key-vim.host.VirtualNic-vmk0",
                            "portGroup": "Management Network",
                            "dPortGroup": "",
                            "ipAddress": "10.19.2.13",
                            "subnetMask": "255.255.255.128",
                            "mtu": 1500
                        },
                        {
                            "key": "key-vim.host.VirtualNic-vmk1",
                            "portGroup": "Storage Network",
                            "dPortGroup": "",
                            "ipAddress": "172.31.2.13",
                            "subnetMask": "255.255.0.0",
                            "mtu": 1500
                        },
                        {
                            "key": "key-vim.host.VirtualNic-vmk3",
                            "portGroup": "",
                            "dPortGroup": "dvportgroup-48",
                            "ipAddress": "192.168.61.13",
                            "subnetMask": "255.255.255.0",
                            "mtu": 1500
                        },
                        {
                            "key": "key-vim.host.VirtualNic-vmk4",
                            "portGroup": "VM_DHCP_Network",
                            "dPortGroup": "",
                            "ipAddress": "10.19.2.231",
                            "subnetMask": "255.255.255.128",
                            "mtu": 1500
                        }
                    ],
                    "portGroups": [
                        {
                            "key": "key-vim.host.PortGroup-VM Network",
                            "name": "VM Network",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch0"
                        },
                        {
                            "key": "key-vim.host.PortGroup-Management Network",
                            "name": "Management Network",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch0"
                        },
                        {
                            "key": "key-vim.host.PortGroup-VM_10G_Network",
                            "name": "VM_10G_Network",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch1"
                        },
                        {
                            "key": "key-vim.host.PortGroup-VM_Storage",
                            "name": "VM_Storage",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch1"
                        },
                        {
                            "key": "key-vim.host.PortGroup-VM_DHCP_Network",
                            "name": "VM_DHCP_Network",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch1"
                        },
                        {
                            "key": "key-vim.host.PortGroup-Storage Network",
                            "name": "Storage Network",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch1"
                        },
                        {
                            "key": "key-vim.host.PortGroup-VM_Isolated_67",
                            "name": "VM_Isolated_67",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch2"
                        },
                        {
                            "key": "key-vim.host.PortGroup-VM_Migration",
                            "name": "VM_Migration",
                            "vSwitch": "key-vim.host.VirtualSwitch-vSwitch2"
                        }
                    ],
                    "switches": [
                        {
                            "key": "key-vim.host.VirtualSwitch-vSwitch0",
                            "name": "vSwitch0",
                            "portGroups": [
                                "key-vim.host.PortGroup-VM Network",
                                "key-vim.host.PortGroup-Management Network"
                            ],
                            "pNICs": [
                                "key-vim.host.PhysicalNic-vmnic4"
                            ]
                        },
                        {
                            "key": "key-vim.host.VirtualSwitch-vSwitch1",
                            "name": "vSwitch1",
                            "portGroups": [
                                "key-vim.host.PortGroup-VM_10G_Network",
                                "key-vim.host.PortGroup-VM_Storage",
                                "key-vim.host.PortGroup-VM_DHCP_Network",
                                "key-vim.host.PortGroup-Storage Network"
                            ],
                            "pNICs": [
                                "key-vim.host.PhysicalNic-vmnic2",
                                "key-vim.host.PhysicalNic-vmnic0"
                            ]
                        },
                        {
                            "key": "key-vim.host.VirtualSwitch-vSwitch2",
                            "name": "vSwitch2",
                            "portGroups": [
                                "key-vim.host.PortGroup-VM_Isolated_67",
                                "key-vim.host.PortGroup-VM_Migration"
                            ],
                            "pNICs": [
                                "key-vim.host.PhysicalNic-vmnic3",
                                "key-vim.host.PhysicalNic-vmnic1"
                            ]
                        }
                    ]
                },
                "networks": [
                    {
                        "kind": "Network",
                        "id": "network-31"
                    },
                    {
                        "kind": "Network",
                        "id": "network-34"
                    },
                    {
                        "kind": "Network",
                        "id": "network-57"
                    },
                    {
                        "kind": "Network",
                        "id": "network-33"
                    },
                    {
                        "kind": "Network",
                        "id": "dvportgroup-47"
                    }
                ],
                "datastores": [
                    {
                        "kind": "Datastore",
                        "id": "datastore-35"
                    },
                    {
                        "kind": "Datastore",
                        "id": "datastore-63"
                    }
                ],
                "vms": null,
                "networkAdapters": [],
                "cluster": {
                    "id": "domain-c26",
                    "parent": {
                        "kind": "Folder",
                        "id": "group-h23"
                    },
                    "revision": 1,
                    "name": "mycluster",
                    "selfLink": "providers/vsphere/c872d364-d62b-46f0-bd42-16799f40324e/clusters/domain-c26",
                    "folder": "group-h23",
                    "networks": [
                        {
                            "kind": "Network",
                            "id": "network-31"
                        },
                        {
                            "kind": "Network",
                            "id": "network-34"
                        },
                        {
                            "kind": "Network",
                            "id": "network-57"
                        },
                        {
                            "kind": "Network",
                            "id": "network-33"
                        },
                        {
                            "kind": "Network",
                            "id": "dvportgroup-47"
                        }
                    ],
                    "datastores": [
                        {
                            "kind": "Datastore",
                            "id": "datastore-35"
                        },
                        {
                            "kind": "Datastore",
                            "id": "datastore-63"
                        }
                    ],
                    "hosts": [
                        {
                            "kind": "Host",
                            "id": "host-44"
                        },
                        {
                            "kind": "Host",
                            "id": "host-29"
                        }
                    ],
                    "dasEnabled": false,
                    "dasVms": [],
                    "drsEnabled": true,
                    "drsBehavior": "fullyAutomated",
                    "drsVms": [],
                    "datacenter": null
                }
            }
        }
    }

6.2.4. Creating a validation rule

You create a validation rule by applying a config map custom resource (CR) containing the rule to the Validation service.

Important
  • If you create a rule with the same name as an existing rule, the Validation service performs an OR operation with the rules.
  • If you create a rule that contradicts a default rule, the Validation service will not start.

Validation rule example

Validation rules are based on virtual machine (VM) attributes collected by the Provider Inventory service.

For example, the VMware API uses this path to check whether a VMware VM has NUMA node affinity configured: MOR:VirtualMachine.config.extraConfig["numa.nodeAffinity"].

The Provider Inventory service simplifies this configuration and returns a testable attribute with a list value:

"numaNodeAffinity": [
    "0",
    "1"
],

You create a Rego query, based on this attribute, and add it to the forklift-validation-config config map:

`count(input.numaNodeAffinity) != 0`

Procedure

  1. Create a config map CR according to the following example:

    $ cat << EOF | oc apply -f -
    apiVersion: v1
    kind: ConfigMap
    metadata:
      name: <forklift-validation-config>
      namespace: openshift-mtv
    data:
      vmware_multiple_disks.rego: |-
        package <provider_package> 1
    
        has_multiple_disks { 2
          count(input.disks) > 1
        }
    
        concerns[flag] {
          has_multiple_disks 3
            flag := {
              "category": "<Information>", 4
              "label": "Multiple disks detected",
              "assessment": "Multiple disks detected on this VM."
            }
        }
    EOF
    1
    Specify the provider package name. Allowed values are io.konveyor.forklift.vmware for VMware and io.konveyor.forklift.ovirt for Red Hat Virtualization.
    2
    Specify the concerns name and Rego query.
    3
    Specify the concerns name and flag parameter values.
    4
    Allowed values are Critical, Warning, and Information.
  2. Stop the Validation pod by scaling the forklift-controller deployment to 0:

    $ oc scale -n openshift-mtv --replicas=0 deployment/forklift-controller
  3. Start the Validation pod by scaling the forklift-controller deployment to 1:

    $ oc scale -n openshift-mtv --replicas=1 deployment/forklift-controller
  4. Check the Validation pod log to verify that the pod started:

    $ oc logs -f <validation_pod>

    If the custom rule conflicts with a default rule, the Validation pod will not start.

  5. Remove the source provider:

    $ oc delete provider <provider> -n openshift-mtv
  6. Add the source provider to apply the new rule:

    $ cat << EOF | oc apply -f -
    apiVersion: forklift.konveyor.io/v1beta1
    kind: Provider
    metadata:
      name: <provider>
      namespace: openshift-mtv
    spec:
      type: <provider_type> 1
      url: <api_end_point> 2
      secret:
        name: <secret> 3
        namespace: openshift-mtv
    EOF
    1
    Allowed values are ovirt and vsphere.
    2
    Specify the API end point URL, for example, https://<vCenter_host>/sdk for vSphere or https://<{rhv-short}_engine_host>/ovirt-engine/api/ for RHV.
    3
    Specify the name of the provider Secret CR.

You must update the rules version after creating a custom rule so that the Inventory service detects the changes and validates the VMs.

6.2.5. Updating the inventory rules version

You must update the inventory rules version each time you update the rules so that the Provider Inventory service detects the changes and triggers the Validation service.

The rules version is recorded in a rules_version.rego file for each provider.

Procedure

  1. Retrieve the current rules version:

    $ GET https://forklift-validation/v1/data/io/konveyor/forklift/<provider>/rules_version 1

    Example output

    {
       "result": {
           "rules_version": 5
       }
    }

  2. Connect to the terminal of the Validation pod:

    $ oc rsh <validation_pod>
  3. Update the rules version in the /usr/share/opa/policies/io/konveyor/forklift/<provider>/rules_version.rego file.
  4. Log out of the Validation pod terminal.
  5. Verify the updated rules version:

    $ GET https://forklift-validation/v1/data/io/konveyor/forklift/<provider>/rules_version 1

    Example output

    {
       "result": {
           "rules_version": 6
       }
    }