Challenge
The HiveMQ operator (since 0.9.0) as well as the HiveMQ Docker images (since 4.6.4) introduced some breaking changes. The. following manual shows how to execute a zero downtime rolling upgrade from older operator and HiveMQ versions.
Prerequisites:
k8s version 1.16+ is installed
Helm version 3 is installed
Hivemq k8s operator repo is already added
Expected Result:
Here we will show the necessary steps for a zero-downtime upgrade of both the HiveMQ k8s operator as well as HiveMQ itself.
Upgrade hivemq version without downtime. Hivemq version 4.6.4 should be running without error using k8s operator version 0.9.2
Steps to follow:
Hivemq cluster values file:
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Code Block | ||
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monitoring: enabled: true operator: admissionWebhooks: enabled: false failurePolicy: Fail deployCr: false logLevel: DEBUG |
Deploy Hivemq operator with 0.8.7
Code Block language bash helm upgrade --version 0.8.7 --install -f operator.yaml <release name> hivemq/hivemq-operator
Apply Hivemq cluster with hivemq 4.6.2
Code Block language bash kubectl apply -f <hivemq cluster.yaml>
Simply apply the new CRD using the following command (considering k8s version is 1.16+)
Note: This step can be skipped if you are using BladeCenter.Code Block language bash kubectl apply -f https://raw.githubusercontent.com/hivemq/helm-charts/prerelease-4.6.4/charts/hivemq-operator/crds/hivemq-cluster.yaml
Scale operator to 0 so it doesn’t immediately reconcile. This will only remove the operator pod, but leave the HiveMQ nodes as remaining
Code Block kubectl scale —replicas=0 deployment <operator name>
Edit hivemq cluster yaml to update the hivemq version as 4.6.4
Apply the changes
Code Block Kubectl apply -f <hivemq cluster.yaml>
check the pods status(no errors)
Code Block kubectl get pods
Update operator version i.e 0.9.2 in cluster(operator config File)
Run the following command for rolling upgrade
Code Block helm upgrade --version 0.9.2 --install -f operator.yaml <release name> hivemq/hivemq-operator