Customize migration plan for WordPress sites

Important: The Migrate to Containers UI in the Google Cloud console, migctl, and CRDs that use processing clusters to migrate workloads to Google Cloud are now deprecated. They are supported for existing users until May 2024, after which they will no longer be available. If you're new to Migrate to Containers, then use the Migrate to Containers CLI to perform migrations on your local machine. For more information, see Migrate to Containers CLI architecture.

You should review the migration plan file that resulted from creating a migration. Customize the file before executing the migration. The details of your migration plan are used to extract the workload container artifacts from the source.

This section describes the contents of the migration and the kinds of customizations that you might consider before you execute the migration and generate deployment artifacts.

Before you begin

• Ensure that you've already created a migration and have the migration plan file.

• If your WordPress site relies on a database connection, then ensure that the database is accessible from the target cluster as Migrate to Containers doesn't automatically migrate it.

Note: To change the site's URL as part of the migration, you need to update the database contents.

Edit the migration plan

You can edit the migration plan by using the migctl tool or the Google Cloud console.

migctl

You must download the migration plan before you can edit it:

1. Download the migration plan.

   migctl migration get my-migration
   

2. Edit the downloaded migration plan, my-migration.yaml, in a text editor.

3. When your edits are complete, save and upload the revised migration plan:

   migctl migration update my-migration --main-config my-migration.yaml
   

4. Repeat these steps if more edits are necessary.

Console

Edit the migration plan in the Google Cloud console by using the YAML editor.

1. Open the Migrate to Containers page in the Google Cloud console.

   Go to the Migrate to Containers page.

2. Click the Migrations tab to display a table containing the available migrations.

3. In the row for your desired migration, select the migration Name to open the Details tab.

4. Select the YAML tab.

   Note: You can also select Download Migration Plan to download a local copy.

5. Edit the migration plan as necessary.

6. When you are done editing, you can either:

   1. Save the migration plan. You then have to manually execute the migration to generate the migration artifacts. Use the procedure shown in Executing a migration.

   2. Save and generate the artifacts. Execute the migration by using your edits to generate the migration artifacts. The process is the same as described in Executing a migration.

CRD

You must download the migration plan, edit it, then apply it. The migration plan is stored inside the appXGenerateArtifactsConfig field of the AppXGenerateArtifactsFlowSpec CRD.

1. Get the name of the AppXGenerateArtifactsFlow:

   kubectl get migrations.anthos-migrate.cloud.google.com -n v2k-system -o jsonpath={.status.migrationPlanRef.name} my-migration

   The naming pattern is returned in the form of appx-generateartifactsflow-id.

2. Get the migration plan by name and write to a file named my-plan.yaml:

   kubectl -n v2k-system get appxgenerateartifactsflows.anthos-migrate.cloud.google.com -o jsonpath=            {.spec.appXGenerateArtifactsConfig} appx-generateartifactsflow-id > my-plan.yaml

3. Edit the migration plan as necessary.

4. Apply the file:

   kubectl patch appxgenerateartifactsflows.anthos-migrate.cloud.google.com --type merge -n v2k-system --patch '{"spec": {"appXGenerateArtifactsConfig": '"$(jq -n --rawfile plan my-plan.yaml '$plan')"'}}' appx-generateartifactsflow-id

Migration plan structure

The migration plan for a WordPress workload has the following structure, which you can customize as described in the following sections.

sites:
- # Image name. Edit this to change the artifacts naming.
  imageName: wordpress
  # Parent WordPress image for the generated container image.
  fromImage: wordpress:6.1-php7.4-apache
  # WordPress root directory.
  rootDirectory: /var/www/html/
  # Database connection values.
  databaseValues:
  - name: DB_NAME
    value: database_name_here
  - name: DB_USER
    value: username_here
  - name: DB_PASSWORD
    value: password_here
  - name: DB_HOST
    value: host_here

To add information as needed, review your migration plan details and guiding comments.

Specifically, consider edits around the following sections.

Specify the Docker image

In the migration plan, generate a Docker community image tag based on the WordPress version.

If you want to change the Docker community image, or provide your own docker image, you can modify the fromImage tag in your migration plan using the following format:

# Parent WordPress image for the generated container image.
  fromImage: wordpress:6.1-php7.4-apache

Specify the database connection configuration

The databaseValues section contains the database connection configuration extracted from the VM. Modify these values to change the database connection.

These values are passed to the migrated pod.

Data migration plan structure

The data migration plan for a WordPress workload has the following structure:

volumes:
- deploymentPvcName: wordpress-pvc
  folders:
  - /var/www/html/wp-content
  newPvc:
    spec:
      accessModes:
      - ReadWriteOnce
      resources:
        requests:
          storage: 10G

The uploaded content, plugins, and themes that reside in the wp-content folder in your WordPress VM are exported to a persistent volume claim (PVC). The PVC is attached and mounted to the migrated pod.

If you updated the data configuration plan, upload it to continue with the migration.

What's next

• Learn how to execute the migration.
• Learn how to monitor the migration.