Red Hat Summit Red Hat SummitSupportConsoleDéveloppeursCommencer un essaiContact

Ce contenu n'est pas disponible dans la langue sélectionnée.

Chapter 12. Advanced migration options

12.1. Changing precopy intervals for warm migration
Copier lien

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
    Copy to Clipboard Toggle word wrap
    1
    Specify the precopy interval in minutes. The default value is 60.

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

12.2. Creating custom rules for the Validation service
Copier lien

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.

12.2.1. About Rego files
Copier lien

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."
    }
}
Copy to Clipboard Toggle word wrap

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.

12.2.2. Checking the default validation rules
Copier lien

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>
    Copy to Clipboard Toggle word wrap

  2. Go to the OPA policies directory for your provider: 

    $ cd /usr/share/opa/policies/io/konveyor/forklift/<provider>
    1
    Copy to Clipboard Toggle word wrap
    1
    Specify vmware or ovirt.

  3. Search for the default policies: 

    $ grep -R "default" *
    Copy to Clipboard Toggle word wrap

12.2.3. Creating a validation rule
Copier lien

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"
],
Copy to Clipboard Toggle word wrap

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

`count(input.numaNodeAffinity) != 0`
Copy to Clipboard Toggle word wrap

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
    Copy to Clipboard Toggle word wrap
    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
    Copy to Clipboard Toggle word wrap

  3. Start the Validation pod by scaling the forklift-controller deployment to 1: 

    $ oc scale -n openshift-mtv --replicas=1 deployment/forklift-controller
    Copy to Clipboard Toggle word wrap

  4. Check the Validation pod log to verify that the pod started: 

    $ oc logs -f <validation_pod>
    Copy to Clipboard Toggle word wrap

    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
    Copy to Clipboard Toggle word wrap

  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
    Copy to Clipboard Toggle word wrap
    1
    Allowed values are ovirt, vsphere, and openstack.
    2
    Specify the API end point URL, for example, https://<vCenter_host>/sdk for vSphere, https://<engine_host>/ovirt-engine/api for RHV, or https://<identity_service>/v3 for OpenStack.
    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.

12.2.4. Updating the inventory rules version
Copier lien

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
    Copy to Clipboard Toggle word wrap

    Example output

    {
   "result": {
       "rules_version": 5
   }
}
    Copy to Clipboard Toggle word wrap

  2. Connect to the terminal of the Validation pod: 

    $ oc rsh <validation_pod>
    Copy to Clipboard Toggle word wrap
  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
    Copy to Clipboard Toggle word wrap

    Example output

    {
   "result": {
       "rules_version": 6
   }
}
    Copy to Clipboard Toggle word wrap

12.3. Retrieving the Inventory service JSON
Copier lien

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 routes for the project: 

    oc get route -n openshift-mtv
    Copy to Clipboard Toggle word wrap

  2. Retrieve the Inventory service route: 

    $ oc get route <inventory_service> -n openshift-mtv
    Copy to Clipboard Toggle word wrap

  3. Retrieve the access token: 

    $ TOKEN=$(oc whoami -t)
    Copy to Clipboard Toggle word wrap

  4. Trigger an HTTP GET request (for example, using Curl): 

    $ curl -H "Authorization: Bearer $TOKEN" https://<inventory_service_route>/providers -k
    Copy to Clipboard Toggle word wrap

  5. Retrieve the UUID of a provider: 

    $ curl -H "Authorization: Bearer $TOKEN"  https://<inventory_service_route>/providers/<provider> -k
    1
    Copy to Clipboard Toggle word wrap
    1 1 1
    Allowed values for the provider are vsphere, ovirt, and openstack.

  6. Retrieve the VMs of a provider: 

    $ curl -H "Authorization: Bearer $TOKEN"  https://<inventory_service_route>/providers/<provider>/<UUID>/vms -k
    Copy to Clipboard Toggle word wrap

  7. Retrieve the details of a VM: 

    $ curl -H "Authorization: Bearer $TOKEN"  https://<inventory_service_route>/providers/<provider>/<UUID>/workloads/<vm> -k
    Copy to Clipboard Toggle word wrap

    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 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
            }
        }
    }
}
    Copy to Clipboard Toggle word wrap

12.4. Adding hooks to an MTV migration plan
Copier lien

You can add hooks to an Migration Toolkit for Virtualization (MTV) migration plan to perform automated operations on a VM, either before or after you migrate it.

12.4.1. About hooks for MTV migration plans
Copier lien

You can add hooks to Migration Toolkit for Virtualization (MTV) migration plans using either the MTV CLI or the MTV user interface, which is located in the Red Hat OpenShift web console.

  • Pre-migration hooks are hooks that perform operations on a VM that is located on a provider. This prepares the VM for migration.
  • Post-migration hooks are hooks that perform operations on a VM that has migrated to OpenShift Virtualization.

12.4.1.1. Default hook image
Copier lien

The default hook image for an MTV hook is quay.io/konveyor/hook-runner. The image is based on the Ansible Runner image with the addition of python-openshift to provide Ansible Kubernetes resources and a recent oc binary.

12.4.1.2. Hook execution
Copier lien

An Ansible playbook that is provided as part of a migration hook is mounted into the hook container as a ConfigMap. The hook container is run as a job on the desired cluster in the openshift-mtv namespace using the ServiceAccount you choose.

When you add a hook, you must specify the namespace where the Hook CR is located, the name of the hook, and whether the hook is a pre-migration hook or a post-migration hook.

Important

In order for a hook to run on a VM, the VM must be started and available using SSH.

The illustration that follows shows the general process of using a migration hook. For specific procedures, see Adding a migration hook to a migration plan using the Red Hat OpenShift web console and Adding a migration hook to a migration plan using the CLI.

Figure 12.1. Adding a hook to a migration plan

Adding a hook to a migration plan
View larger image
Adding a hook to a migration plan

Process:

  1. Input your Ansible hook and credentials.

    1. Input an Ansible hook image to the MTV controller using either the UI or the CLI.

      • In the UI, specify the ansible-runner and enter the playbook.yml that contains the hook.
      • In the CLI, input the hook image, which specifies the playbook that runs the hook.

    2. If you need additional data to run the playbook inside the pod, such as SSH data, create a Secret that contains credentials for the VM. The Secret is not mounted to the pod, but is called by the playbook.

      Note

      This Secret is not the same as the Secret CR that contains the credentials of your source provider.

  2. The MTV controller creates the ConfigMap, which contains:

    • workload.yml, which contains information about the VMs.
    • playbook.yml, the raw string playbook you want to execute.

    • plan.yml, which is the Plan CR.

      The ConfigMap contains the name of the VM and instructs the playbook what to do.

  3. The MTV controller creates a job that starts the user specified image.

    1. Mounts the ConfigMap to the container.

      The Ansible hook imports the Secret that the user previously entered.

  4. The job runs a pre-migration hook or a post-migration hook as follows:

    1. For a pre-migration hook, the job logs into the VMs on the source provider using SSH and runs the hook.
    2. For a post-migration hook, the job logs into the VMs on OpenShift Virtualization using SSH and runs the hook.

You can add a migration hook to an existing migration plan using the Red Hat OpenShift web console. Note that you need to run one command in the Migration Toolkit for Virtualization (MTV) CLI.

For example, you can create a hook to install the cloud-init service on a VM and write a file before migration.

Note

You can run one pre-migration hook, one post-migration hook, or one of each per migration plan.

Prerequisites

  • Migration plan
  • Migration hook file, whose contents you copy and paste into the web console
  • File containing the Secret for the source provider
  • Red Hat OpenShift service account called by the hook and that has at least write access for the namespace you are working in
  • SSH access for VMs you want to migrate with the public key installed on the VMs
  • VMs running on Microsoft Server only: Remote Execution enabled

Additional resources

For instructions for creating a service account, see Understanding and creating service accounts.

Procedure

  1. In the Red Hat OpenShift web console, click Migration > Plans for virtualization and then click the migration plan you want to add the hook to.
  2. Click Hooks.

  3. For a pre-migration hook, perform the following steps:

    1. In the Pre migration hook section, toggle the Enable hook switch to Enable pre migration hook.
    2. Enter the Hook runner image. If you are specifying the spec.playbook, you need to use an image that has an ansible-runner.
    3. Paste your hook as a YAML file in the Ansible playbook text box.

  4. For a post-migration hook, perform the following steps:

    1. In the Post migration hook, toggle the Enable hook switch Enable post migration hook.
    2. Enter the Hook runner image. If you are specifying the spec.playbook, you need to use an image that has an ansible-runner.
    3. Paste your hook as a YAML file in the Ansible playbook text box.
  5. At the top of the tab, click Update hooks.

  6. In a terminal, enter the following command to associate each hook with your Red Hat OpenShift service account: 

    $ oc -n openshift-mtv patch hook <name_of_hook> \
  -p '{"spec":{"serviceAccount":"<service_account>"}}' --type merge
    Copy to Clipboard Toggle word wrap

The example migration hook that follows ensures that the VM can be accessed using SSH, creates an SSH key, and runs 2 tasks: stopping the Maria database and generating a text file.

Example migration hook

- name: Main
  hosts: localhost
  vars_files:
    - plan.yml
    - workload.yml
  tasks:
  - k8s_info:
      api_version: v1
      kind: Secret
      name: privkey
      namespace: openshift-mtv
    register: ssh_credentials

  - name: Ensure SSH directory exists
    file:
      path: ~/.ssh
      state: directory
      mode: 0750

  - name: Create SSH key
    copy:
      dest: ~/.ssh/id_rsa
      content: "{{ ssh_credentials.resources[0].data.key | b64decode }}"
      mode: 0600

  - add_host:
      name: "{{ vm.ipaddress }}"  # ALT "{{ vm.guestnetworks[2].ip }}"
      ansible_user: root
      groups: vms

- hosts: vms
  vars_files:
    - plan.yml
    - workload.yml
  tasks:
  - name: Stop MariaDB
    service:
      name: mariadb
      state: stopped

  - name: Create Test File
    copy:
      dest: /premigration.txt
      content: "Migration from {{ provider.source.name }}
                of {{ vm.vm1.vm0.id }} has finished\n"
      mode: 0644
Copy to Clipboard Toggle word wrap

You can use a Hook CR to add a pre-migration hook or a post-migration hook to an existing migration plan using the Migration Toolkit for Virtualization (MTV) CLI.

For example, you can create a Hook CR to install the cloud-init service on a VM and write a file before migration.

Note

You can run one pre-migration hook, one post-migration hook, or one of each per migration plan. Each hook needs its own Hook CR, but a Plan CR contains data for all the hooks it uses.

Note

You can retrieve additional information stored in a secret or in a ConfigMap by using a k8s module.

Prerequisites

  • Migration plan
  • Migration hook image or the playbook containing the hook image
  • File containing the Secret for the source provider
  • Red Hat OpenShift service account called by the hook and that has at least write access for the namespace you are working in
  • SSH access for VMs you want to migrate with the public key installed on the VMs
  • VMs running on Microsoft Server only: Remote Execution enabled

Additional resources

For instructions for creating a service account, see Understanding and creating service accounts.

Procedure

  1. If needed, create a Secret with an SSH private key for the VM.

    1. Choose an existing key or generate a key pair.
    2. Install the public key on the VM.

    3. Encode the private key in the Secret to base64. 

      apiVersion: v1
data:
  key: VGhpcyB3YXMgZ2Vu...
kind: Secret
metadata:
  name: ssh-credentials
  namespace: openshift-mtv
type: Opaque
      Copy to Clipboard Toggle word wrap

  2. Encode your playbook by concatenating a file and piping it for Base64 encoding, for example: 

    $ cat playbook.yml | base64 -w0
    Copy to Clipboard Toggle word wrap

  3. Create a Hook CR: 

    $  cat << EOF | oc apply -f -
apiVersion: forklift.konveyor.io/v1beta1
kind: Hook
metadata:
  name: <hook>
  namespace: <namespace>
spec:
  image: quay.io/konveyor/hook-runner
  serviceAccount:<service account>
    1 
    
  playbook: |
    LS0tCi0gbm...
    2 
    
EOF
    Copy to Clipboard Toggle word wrap
    1
    (Optional) Red Hat OpenShift service account. The serviceAccount must be provided if you want to manipulate any resources of the cluster.
    2
    Base64-encoded Ansible Playbook. If you specify a playbook, the image must include an ansible-runner.
    Note

    You can use the default hook-runner image or specify a custom image. If you specify a custom image, you do not have to specify a playbook.

    Note

    To decode an attached playbook, retrieve the resource with custom output and pipe it to base64. For example: 

    $ oc get -n konveyor-forklift hook playbook -o \
    go-template='{{ .spec.playbook }}' | base64 -d
    Copy to Clipboard Toggle word wrap

  4. In the Plan CR of the migration, for each VM, add the following section to the end of the CR: 

      vms:
    - id: <vm_id>
      hooks:
        - hook:
            namespace: <namespace>
            name: <name_of_hook>
          step: <type_of_hook>
    1
    Copy to Clipboard Toggle word wrap
    1
    Options are PreHook, to run the hook before the migration, and PostHook, to run the hook after the migration.
Important

In order for a PreHook to run on a VM, the VM must be started and available via SSH.

The example migration hook that follows ensures that the VM can be accessed using SSH, creates an SSH key, and runs 2 tasks: stopping the Maria database and generating a text file.

Example migration hook

- name: Main
  hosts: localhost
  vars_files:
    - plan.yml
    - workload.yml
  tasks:
  - k8s_info:
      api_version: v1
      kind: Secret
      name: privkey
      namespace: openshift-mtv
    register: ssh_credentials

  - name: Ensure SSH directory exists
    file:
      path: ~/.ssh
      state: directory
      mode: 0750

  - name: Create SSH key
    copy:
      dest: ~/.ssh/id_rsa
      content: "{{ ssh_credentials.resources[0].data.key | b64decode }}"
      mode: 0600

  - add_host:
      name: "{{ vm.ipaddress }}"  # ALT "{{ vm.guestnetworks[2].ip }}"
      ansible_user: root
      groups: vms

- hosts: vms
  vars_files:
    - plan.yml
    - workload.yml
  tasks:
  - name: Stop MariaDB
    service:
      name: mariadb
      state: stopped

  - name: Create Test File
    copy:
      dest: /premigration.txt
      content: "Migration from {{ provider.source.name }}
                of {{ vm.vm1.vm0.id }} has finished\n"
      mode: 0644
Copy to Clipboard Toggle word wrap

Retour au début
Red Hat logoGithubredditYoutubeTwitter

Apprendre

Essayez, achetez et vendez

Communautés

À propos de la documentation Red Hat

Nous aidons les utilisateurs de Red Hat à innover et à atteindre leurs objectifs grâce à nos produits et services avec un contenu auquel ils peuvent faire confiance. Découvrez nos récentes mises à jour.

Rendre l’open source plus inclusif

Red Hat s'engage à remplacer le langage problématique dans notre code, notre documentation et nos propriétés Web. Pour plus de détails, consultez le Blog Red Hat.

À propos de Red Hat

Nous proposons des solutions renforcées qui facilitent le travail des entreprises sur plusieurs plates-formes et environnements, du centre de données central à la périphérie du réseau.

Theme

© 2025 Red Hat