1. Identify a pair of running OpenShift clusters to migrate workloads between
mig-controller and mig-ui can help you move workloads from a source to a destination cluster. You'll need cluster-admin permissions on both clusters.
- velero will need to be installed on both clusters, and will be driven by mig-controller
- mig-controller and mig-ui should only be installed on one of the two clusters. You can decide which cluster will host these components.
2. Deploy Velero to both the source and destination OpenShift clusters
# Download bash script to deploy Velero along with required plugins
$ wget https://raw.githubusercontent.com/fusor/mig-controller/master/hack/deploy/deploy_velero.sh
# Login to source cluster, run deploy_velero.sh against it
$ oc login https://my-source-cluster:8443
$ bash deploy_velero.sh
Deploying Velero...
[...]
# Login to destination cluster, run deploy_velero.sh against it
$ oc login https://my-destination-cluster:8443
$ bash deploy_velero.sh
Deploying Velero...
[...]
3. Deploy mig-controller and mig-ui to one of the two involved clusters
# Download bash script to deploy latest mig-controller and mig-ui images
$ wget https://raw.githubusercontent.com/fusor/mig-controller/master/hack/deploy/deploy_mig.sh
# Login to cluster of your choice where controller + UI will run
$ oc login https://my-cluster:8443
$ bash deploy_mig.sh
Deploying mig-controller...
[...]
Deploying mig-ui...
[...]
4. Create Mig CRs to describe the Migration that will be performed
Before mig-controller can run a Migration, you'll need to provide it with:
- Coordinates & auth info for 2 OpenShift clusters (source + destination)
- A list of namespaces to be migrated
- Storage to use for the migration
These items can be specified by "Mig" CRs. For the source of truth on what will be accepted in CR fields, see the appropriate types.go file.
To make it easier to run your first Migration with mig-controller, we've published a set of annotated sample CRs in config/samples that you can walk through and fill out values on. The first step will be to run make samples, which will copy these to migsamples.
make samples
# [... sample CR content will be copied to 'migsamples' dir, which is .gitignored]
These sample resources describe a migration where the source cluster is running the controller, so a Service Account (SA) token and cluster URL must be provided for the destination cluster only.
Inspect and edit each of the files in the 'migsamples' directory, making changes as needed. Much of the content in these sample files can stay unchanged.
As an example, you'll need to provide the following parameters to perform a Migration using an AWS S3 bucket as temporary migration storage:
| Parameter | Purpose | Sample CR File |
|---|---|---|
namespaces |
List of namespaces to migrate from source to destination cluster | mig-plan.yaml |
serverAddress |
Endpoint of remote cluster mig-controller will connect to | cluster-remote.yaml |
saToken |
Base64 encoded SA token used to authenticate with remote cluster | sa-secret-remote.yaml |
awsBucketName |
Name of the S3 bucket to be used for temporary Migration storage | mig-storage.yaml |
awsRegion |
Region of S3 bucket to be used for temporary Migration storage | mig-storage.yaml |
aws-access-key-id |
AWS access key to auth with AWS services | mig-storage-creds.yaml |
aws-secret-access-key |
AWS secret access key to auth with AWS services | mig-storage-creds.yaml |
After modifying resource yaml, create the resources on the OpenShift cluster where the controller is running.
# Option 1: Create everything in a single command
oc apply -f migsamples
# ------------------------------------------------
# Option 2: Create resources individually
cd migsamples
# Source cluster definition
# Note: no coordinates/auth needed when MigCluster has 'isHostCluster: true'
oc apply -f mig-cluster-local.yaml
# Destination cluster definition, coordinates, auth details
oc apply -f cluster-remote.yaml
oc apply -f sa-secret-remote.yaml
oc apply -f mig-cluster-remote.yaml
# Describes where to store data during Migration, storage auth details
# Note: the contents of mig-storage-creds.yaml will be used to overwrite Velero cloud-credentials
oc apply -f mig-storage-creds.yaml
oc apply -f mig-storage.yaml
# Describes which clusters, storage, and namespaces should be to run a Migration
oc apply -f mig-plan.yaml
# Declares that a Migration operation should be run
oc apply -f mig-migration.yaml
For mig-controller to perform migration actions on a remote cluster, you'll need to provide a valid Service Account (SA) token granting 'cluster-admin' access to the remote cluster.
To configure the SA token, run the following on the remote cluster:
# Create a new service account in the mig ns
oc create namespace mig
oc create sa -n mig mig
# Grant the 'mig' service account cluster-admin (cluster level root privileges, use with caution!)
oc adm policy add-cluster-role-to-user cluster-admin system:serviceaccount:mig:mig
# Get the ServiceAccount token in a base64-encoded format to put in the remote MigCluster spec
oc sa get-token -n mig mig|base64 -w 0
Use the base64-encoded SA token from the last command output to fill in migsamples/sa-secret-remote.yaml