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This is the initial pod disruption budget that will serve as the template for all services in OpenStack-Helm. Partially-Implements: blueprint add-pod-disruption-budgets Change-Id: I67eeaa66257e793f77a089f3bc0dd4b700638c63
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1.4 KiB
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34 lines
1.4 KiB
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=====================
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Kubernetes Operations
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=====================
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Init-Containers
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===============
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Jobs
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====
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Pod Disruption Budgets
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======================
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OpenStack-Helm leverages PodDistruptionBudgets to enforce quotas
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that ensure that a certain number of replicas of a pod are available
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at any given time. This is particularly important in the case when a Kubernetes
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node needs to be drained.
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These quotas are configurable by modifying the ``minAvailable`` field
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within each PodDistruptionBudget manifest, which is conveniently mapped
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to a templated variable inside the ``values.yaml`` file.
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The ``min_available`` within each service's ``values.yaml`` file can be
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represented by either a whole number, such as ``1``, or a percentage,
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such as ``80%``. For example, when deploying 5 replicas of a pod (such as
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keystone-api), using ``min_available: 3`` would enfore policy to ensure at
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least 3 replicas were running, whereas using ``min_available: 80%`` would ensure
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that 4 replicas of that pod are running.
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**Note:** The values defined in a PodDisruptionBudget may
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conflict with other values that have been provided if an operator chooses to
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leverage Rolling Updates for deployments. In the case where an
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operator defines a ``maxUnavailable`` and ``maxSurge`` within an update strategy
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that is higher than a ``minAvailable`` within a pod disruption budget,
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a scenario may occur where pods fail to be evicted from a deployment. |