Troubleshooting upgrade
For a high level overview of the upgrade lifecycle and components, please refer to the related document.
Rancher side​
In this example we upgraded the cluster nodes with the following ManagedOSImage definition:
apiVersion: elemental.cattle.io/v1beta1
kind: ManagedOSImage
metadata:
name: my-upgrade
namespace: fleet-default
spec:
# Set to the new Elemental version you would like to upgrade to or track the latest tag
osImage: "registry.suse.com/rancher/sle-micro/5.5:latest"
clusterTargets:
- clusterName: my-cluster
Once the ManagedOSImage is applied, the elemental-operator will verify it and generate a related Bundle.
The Bundle name will be prefixed with mos and then the ManagedOSImage name. In this case mos-my-upgrade.
In the Bundle definition, you will find the details about the upgrade plan and the desired target.
For example:
kubectl -n fleet-default get bundle mos-my-upgrade -o yaml
Example
apiVersion: fleet.cattle.io/v1alpha1
kind: Bundle
metadata:
creationTimestamp: "2023-06-16T09:01:47Z"
generation: 1
name: mos-my-upgrade
namespace: fleet-default
ownerReferences:
- apiVersion: elemental.cattle.io/v1beta1
controller: true
kind: ManagedOSImage
name: my-upgrade
uid: e468ed21-23bb-487a-a022-dbc7ef753720
resourceVersion: "1038645"
uid: 35e83fc4-28c8-4b10-8059-cae6cdff2cda
spec:
resources:
- content: '{"kind":"ClusterRole","apiVersion":"rbac.authorization.k8s.io/v1","metadata":{"name":"os-upgrader-my-upgrade","creationTimestamp":null},"rules":[{"verbs":["update","get","list","watch","patch"],"apiGroups":[""],"resources":["nodes"]},{"verbs":["list"],"apiGroups":[""],"resources":["pods"]}]}'
name: ClusterRole--os-upgrader-my-upgrade-296a3abf3451.yaml
- content: '{"kind":"ClusterRoleBinding","apiVersion":"rbac.authorization.k8s.io/v1","metadata":{"name":"os-upgrader-my-upgrade","creationTimestamp":null},"subjects":[{"kind":"ServiceAccount","name":"os-upgrader-my-upgrade","namespace":"cattle-system"}],"roleRef":{"apiGroup":"rbac.authorization.k8s.io","kind":"ClusterRole","name":"os-upgrader-my-upgrade"}}'
name: ClusterRoleBinding--os-upgrader-my-upgrade-f63eaecde935.yaml
- content: '{"kind":"ServiceAccount","apiVersion":"v1","metadata":{"name":"os-upgrader-my-upgrade","namespace":"cattle-system","creationTimestamp":null}}'
name: ServiceAccount-cattle-system-os-upgrader-my-upgrade-ce93d-01096.yaml
- content: '{"kind":"Secret","apiVersion":"v1","metadata":{"name":"os-upgrader-my-upgrade","namespace":"cattle-system","creationTimestamp":null},"data":{"cloud-config":""}}'
name: Secret-cattle-system-os-upgrader-my-upgrade-a997ee6a67ef.yaml
- content: '{"kind":"Plan","apiVersion":"upgrade.cattle.io/v1","metadata":{"name":"os-upgrader-my-upgrade","namespace":"cattle-system","creationTimestamp":null},"spec":{"concurrency":1,"nodeSelector":{},"serviceAccountName":"os-upgrader-my-upgrade","version":"latest","secrets":[{"name":"os-upgrader-my-upgrade","path":"/run/data"}],"tolerations":[{"operator":"Exists"}],"cordon":true,"upgrade":{"image":"registry.suse.com/suse/sle-micro/5.5","command":["/usr/sbin/suc-upgrade"]}},"status":{}}'
name: Plan-cattle-system-os-upgrader-my-upgrade-273c2c09afca.yaml
targets:
- clusterName: my-cluster
.
.
.
Elemental Cluster side​
Any Elemental node correctly registered and part of the target cluster will fetch the bundle and start applying it.
This operation is performed by the Rancher's system-upgrade-controller running on the Elemental Cluster.
To monitor the correct operation of this controller, you can read its logs:
kubectl -n cattle-system logs deployment/system-upgrade-controller
If everything is correct, the system-upgrade-controller will create an upgrade Plan on the cluster:
kubectl -n cattle-system get plans
For each Plan, the controller will orchestrate the jobs that will apply it on each targeted node.
The job names will use the Plan name (os-upgrader-my-upgrade) and the target machine hostname (my-host) for easy discoverability.
For example: apply-os-upgrader-my-upgrade-on-my-host-7a25e
You can monitor these jobs with:
kubectl -n cattle-system get jobs
Each job will use a privileged: true container with the SLE Micro image specified in the ManagedOSImage definition. This container will try to upgrade the system and perform a reboot.
If the job fails, you can check its status by examining the logs:
kubectl -n cattle-system logs job.batch/apply-os-upgrader-my-upgrade-on-my-host-7a25e
Note that the upgrade process is performed in two stages.
You will notice that the same job is ran twice and the first one ends with the Uknown Status and will not complete.
This is to be expected, as Elemental relies on the job to be ran again after the machine restarts, so that it can verify the new version was installed correctly.
You will notice a second run of the job, this time completing correctly.
kubectl -n cattle-system get jobs
NAMESPACE NAME COMPLETIONS DURATION AGE
cattle-system apply-os-upgrader-my-upgrade-on-my-host-0b392 1/1 2m34s 6m23s
cattle-system apply-os-upgrader-my-upgrade-on-my-host-7a25e 0/1 6m23s 6m23s
kubectl -n cattle-system get pods
NAME READY STATUS RESTARTS AGE
apply-os-upgrader-my-upgrade-on-my-host-zbkrh 0/1 Completed 0 9m40s
apply-os-upgrader-my-upgrade-on-my-host-zvrff 0/1 Unknown 0 12m
Recovering from failures​
It is possible that the ManagedOSImage upgrade process will fail, leaving one or more nodes in a faulty state.
For example if the to-be-upgraded image is not found on the registry or otherwise broken, the upgrade job running on the downstream clusters will not succeed.
When this is the case, the nodes running the failing upgrade job will stay cordoned.
You can update the ManagedOSImage with a functioning osImage, or alternatively delete it to stop any further upgrade attempt.
In any case, in order to restore them and be able to also schedule following upgrades, the affected nodes need to be uncordoned manually.