isabella232 / nodetaint

nodetaint

Controller to manage taints for nodes in a k8s cluster.

What the problem is

Usually there are some system critical daemonsets (e.g. CNI, DNS, etc.) that needs to be running on a node before it can run any other pods. However k8s doesn't guarantee any ordering for pod scheduling in node startup, meaning your workload pods may start before the critical daemonsets have started!

How it works

The controller solves this problem by removing a pre-configured taint from a node after annotated daemonsets are running on the node. To achieve this, you need to configure your cluster to launch nodes with the desired taint. The controller then determines, through annotation, which daemonsets should be running on a node prior to workload pods. It monitors for these daemonset pods to be Ready before removing the configured taint.

Configuration

Command-line

nodetaint can be configured by the following command-line options:

Flag	Environment Variable	Type	Default	Required	Description
log-level	LOG_LEVEL	string	info	no	The level of log detail.
bind-address	BIND_ADDRESS	string	:9797	no	The address for binding listener.
node-taint	NODE_TAINT	string		yes	The startup taint to put on node.
daemonset-annotation	DAEMONSET_ANNOTATION	string		yes	The annotation of required daemonset.