Description

Kubernetes is an open-source platform for deploying, scaling, and operations
of application containers across a cluster of hosts. Kubernetes is portable
in that it works with public, private, and hybrid clouds. Extensible through
a pluggable infrastructure. Self healing in that it will automatically
restart and place containers on healthy nodes if a node ever goes away.

Kubernetes Worker

Usage

This charm deploys a container runtime, and additionally stands up the Kubernetes
worker applications: kubelet, and kube-proxy.

In order for this charm to be useful, it should be deployed with its companion
charm kubernetes-master
and linked with an SDN-Plugin.

This charm has also been bundled up for your convenience so you can skip the
above steps, and deploy it with a single command:

juju deploy canonical-kubernetes

For more information about Canonical Kubernetes
consult the bundle README.md file.

Scale out

To add additional compute capacity to your Kubernetes workers, you may
juju add-unit scale the cluster of applications. They will automatically
join any related kubernetes-master, and enlist themselves as ready once the
deployment is complete.

Operational actions

The kubernetes-worker charm supports the following Operational Actions:

Pause

Pausing the workload enables administrators to both drain and cordon
a unit for maintenance.

Resume

Resuming the workload will uncordon a paused unit. Workloads will automatically migrate unless otherwise directed via their application declaration.

Known Limitations

Kubernetes workers currently only support 'phaux' HA scenarios. Even when configured with an HA cluster string, they will only ever contact the first unit in the cluster map. To enalbe a proper HA story, kubernetes-worker units are encouraged to proxy through a kubeapi-load-balancer
application. This enables a HA deployment without the need to
re-render configuration and disrupt the worker services.

External access to pods must be performed through a Kubernetes
Ingress Resource
. More
information

Configuration

nagios_servicegroups
(string) A comma-separated list of nagios servicegroups. If left empty, the nagios_context will be used as the servicegroup
ingress
(boolean) Deploy the default http backend and ingress controller to handle ingress requests.
True
labels
(string) Labels can be used to organize and to select subsets of nodes in the cluster. Declare node labels in key=value format, separated by spaces.
no_proxy
(string) Comma-separated list of destinations (either domain names or IP addresses) that should be directly accessed, by opposition of going through the proxy defined above.
install_from_upstream
(boolean) Toggle installation from ubuntu archive vs the docker PPA
http_proxy
(string) URL to use for HTTP_PROXY to be used by Docker. Only useful in closed environments where a proxy is the only option for routing to the registry to pull images
https_proxy
(string) URL to use for HTTPS_PROXY to be used by Docker. Only useful in closed environments where a proxy is the only option for routing to the registry to pull images
nagios_context
(string) Used by the nrpe subordinate charms. A string that will be prepended to instance name to set the host name in nagios. So for instance the hostname would be something like: juju-myservice-0 If you're running multiple environments with the same services in them this allows you to differentiate between them.
juju
docker-opts
(string) Extra options to pass to the docker daemon. e.g. --insecure-registry
enable-cgroups
(boolean) Enable GRUB cgroup overrides cgroup_enable=memory swapaccount=1. WARNING changing this option will reboot the host - use with caution on production services