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MTV-1590 Improved hooks description #586

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Original file line number Diff line number Diff line change
Expand Up @@ -318,13 +318,14 @@ include::modules/creating-validation-rule.adoc[leveloffset=+3]
include::modules/updating-validation-rules-version.adoc[leveloffset=+3]
include::modules/retrieving-validation-service-json.adoc[leveloffset=+2]

[id="adding-hooks-migration-plan-using-api"]
=== Adding hooks to a migration plan
You can add hooks a migration plan from the command line by using the {project-full} API.
[id="adding-hooks-mtv-migration-plan"]
=== Adding hooks to an MTV migration plan

include::modules/about-hook-crs-for-migration-plans-api.adoc[leveloffset=+3]
You can add hooks to an {project-first} migration plan to perform automated operations on a VM, either before or after you migrate it.

include::modules/adding-hook-crs-to-migration-plans-api.adoc[leveloffset=+3]
include::modules/about-hooks-for-migration-plans.adoc[leveloffset=+3]
include::modules/adding-hook-using-ui.adoc[leveloffset=+3]
include::modules/adding-hook-using-cli.adoc[leveloffset=+3]

include::modules/upgrading-mtv-ui.adoc[leveloffset=+1]

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49 changes: 0 additions & 49 deletions documentation/modules/about-hook-crs-for-migration-plans-api.adoc

This file was deleted.

65 changes: 65 additions & 0 deletions documentation/modules/about-hooks-for-migration-plans.adoc
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@@ -0,0 +1,65 @@
// Module included in the following assemblies:
//
// * documentation/doc-Migration_Toolkit_for_Virtualization/master.adoc

:_content-type: CONCEPT
[id="about-hooks-for-migration-plans_{context}"]
= About hooks for {project-short} migration plans

You can add hooks to {project-first} migration plans using either the {project-short} CLI or the {project-short} user interface, which is located in the {ocp} 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 {virt}.

[id="default-hook-image_{context}"]
== Default hook image
The default hook image for an {project-short} 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.

[id="hook-execution_{context}"]
== Hook execution
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 xref:adding-migration-hook-via-ui_{context}[Adding a migration hook to a migration plan using the {ocp} web console] and xref:adding-migration-hook-via-cli_{context}[Adding a migration hook to a migration plan using the CLI].

.Adding a hook to a migration plan
image::migration_hook_process.png[Adding a hook to a migration plan]

*Process:*

. Input your Ansible hook and credentials.

.. Input an Ansible hook image to the {project-short} 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.

.. 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.
====

. The {project-short} 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.

. The {project-short} controller creates a job that starts the user specified image.
.. Mounts the `ConfigMap` to the container.
+
The Ansible hook imports the Secret that the user previously entered.
. The job runs a pre-migration hook or a post-migration hook as follows:

.. For a pre-migration hook, the job logs into the VMs on the source provider using SSH and runs the hook.
.. For a post-migration hook, the job logs into the VMs on {virt} using SSH and runs the hook.
115 changes: 115 additions & 0 deletions documentation/modules/adding-hook-using-cli.adoc
Original file line number Diff line number Diff line change
@@ -0,0 +1,115 @@
// Module included in the following assemblies:
//
// * documentation/doc-Migration_Toolkit_for_Virtualization/master.adoc

:_content-type: PROCEDURE
[id="adding-migration-hook-via-cli_{context}"]
= Adding a migration hook to a migration plan using the CLI

You can use a `Hook` CR to add a pre-migration hook or a post-migration hook to an existing migration plan using the {project-first} 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
* {ocp} 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 link:https://docs.openshift.com/container-platform/{ocp-version}/authentication/understanding-and-creating-service-accounts.html[Understanding and creating service accounts].

.Procedure
. If needed, create a Secret with an SSH private key for the VM.
.. Choose an existing key or generate a key pair.
.. Install the public key on the VM.
.. Encode the private key in the Secret to base64.
+
[source,yaml]
----
apiVersion: v1
data:
key: VGhpcyB3YXMgZ2Vu...
kind: Secret
metadata:
name: ssh-credentials
namespace: openshift-mtv
type: Opaque
----
. Encode your playbook by concatenating a file and piping it for Base64 encoding, for example:
+
[source,shell]
----
$ cat playbook.yml | base64 -w0
----

. Create a Hook CR:
+
[source,yaml,subs="attributes+"]
----
$ 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
----
<1> (Optional) {ocp} 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:
[source,shell]
----
$ oc get -n konveyor-forklift hook playbook -o \
go-template='{{ .spec.playbook }}' | base64 -d
----
====
+
. In the `Plan` CR of the migration, for each VM, add the following section to the end of the CR:
+
[source,yaml]
----
vms:
- id: <vm_id>
hooks:
- hook:
namespace: <namespace>
name: <name_of_hook>
step: <type_of_hook> <1>
----
<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.
====

include::snip_example-hook-for-migration-plans.adoc[]


55 changes: 55 additions & 0 deletions documentation/modules/adding-hook-using-ui.adoc
Original file line number Diff line number Diff line change
@@ -0,0 +1,55 @@
// Module included in the following assemblies:
//
// * documentation/doc-Migration_Toolkit_for_Virtualization/master.adoc

:_content-type: PROCEDURE
[id="adding-migration-hook-via-ui_{context}"]
= Adding a migration hook to a migration plan using the {ocp} web console

You can add a migration hook to an existing migration plan using the {ocp} web console. Note that you need to run one command in the {project-first} 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
* {ocp} 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 link:https://docs.openshift.com/container-platform/{ocp-version}/authentication/understanding-and-creating-service-accounts.html[Understanding and creating service accounts].

.Procedure

. In the {ocp} web console, click *Migration* > *Plans for virtualization* and then click the migration plan you want to add the hook to.
. Click *Hooks*.
. For a pre-migration hook, perform the following steps:

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

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

.. In the *Post migration hook*, toggle the *Enable hook* switch *Enable post migration hook*.
.. Enter the *Hook runner image*. If you are specifying the `spec.playbook`, you need to use an image that has an `ansible-runner`.
.. Paste your hook as a YAML file in the *Ansible playbook* text box.

. At the top of the tab, click *Update hooks*.
. In a terminal, enter the following command to associate each hook with your {ocp} service account:
+
[source,terminal,subs="attributes+"]
----
$ oc -n openshift-mtv patch hook <name_of_hook> \
-p '{"spec":{"serviceAccount":"<service_account>"}}' --type merge
----

include::snip_example-hook-for-migration-plans.adoc[]
2 changes: 1 addition & 1 deletion documentation/modules/common-attributes.adoc
Original file line number Diff line number Diff line change
Expand Up @@ -8,7 +8,7 @@
:ocp: Red Hat OpenShift
:ocp-name: OpenShift
:ocp-short: OpenShift
// when udating the ocp-version, update the ocp-y-version
// when updating the ocp-version, update the ocp-y-version
:ocp-version: 4.17
:ocp-y-version: 4.17, 4.16, 4.15
:operator: mtv-operator
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13 changes: 4 additions & 9 deletions documentation/modules/new-migrating-virtual-machines-cli.adoc
Original file line number Diff line number Diff line change
Expand Up @@ -735,18 +735,13 @@ metadata:
namespace: <namespace>
spec:
image: quay.io/konveyor/hook-runner
serviceAccount:<ervice account> <1>
playbook: |
LS0tCi0gbmFtZTogTWFpbgogIGhvc3RzOiBsb2NhbGhvc3QKICB0YXNrczoKICAtIG5hbWU6IExv
YWQgUGxhbgogICAgaW5jbHVkZV92YXJzOgogICAgICBmaWxlOiAiL3RtcC9ob29rL3BsYW4ueW1s
IgogICAgICBuYW1lOiBwbGFuCiAgLSBuYW1lOiBMb2FkIFdvcmtsb2FkCiAgICBpbmNsdWRlX3Zh
cnM6CiAgICAgIGZpbGU6ICIvdG1wL2hvb2svd29ya2xvYWQueW1sIgogICAgICBuYW1lOiB3b3Jr
bG9hZAoK
LS0tCi0gbm... <2>
EOF
----
+
where:
+
`playbook` refers to an optional Base64-encoded Ansible Playbook. If you specify a playbook, the `image` must be `hook-runner`.
<1> (Optional) {ocp} 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]
====
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54 changes: 54 additions & 0 deletions documentation/modules/snip_example-hook-for-migration-plans.adoc
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@@ -0,0 +1,54 @@
:_content-type: SNIPPET

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
[source,yaml,subs="attributes+"]
----
- 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
----
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