Without an explicit version or imagePullPolicy, k8s will set
imagePullPolicy to Always and automatically upgrades the server image to
a new version without dump/restore in a future k8s re-deployment,
breaking the server if the new version is a major bump.
Setting imagePullPolicy to IfNotPresent is not always safe from the same
issue, because k8s may want to re-deploy the pod onto a new node without
an image of the same major version.
Without an explicit version or imagePullPolicy, k8s will set imagePullPolicy to Always and automatically upgrades the server image to a new version without dump/restore in a future k8s re-deployment, breaking the server if the new version is a major bump.
Setting imagePullPolicy to IfNotPresent is not always safe from the same issue, because k8s may want to re-deploy the pod onto a new node without an image of the same major version.