kubernetes worker #711

Supports: focal bionic xenial
Add to new model

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 and a container runtime such as containerd.

This charm is a component of Charmed Kubernetes. For full information, please visit the official Charmed Kubernetes docs.

Developers

Building the charm

make charm

Configuration

allow-privileged
(string) This option is now deprecated and has no effect.
true
channel
(string) Snap channel to install Kubernetes worker services from
1.19/stable
default-backend-image
(string) Docker image to use for the default backend. Auto will select an image based on architecture.
auto
ingress
(boolean) Deploy the default http backend and ingress controller to handle ingress requests. Set to false if deploying an alternate ingress controller, and note that you may need to manually open ports 80 and 443 on the nodes: juju run --application kubernetes-worker -- open-port 80 && open-port 443
True
ingress-default-ssl-certificate
(string) SSL certificate to be used by the default HTTPS server. If one of the flag ingress-default-ssl-certificate or ingress-default-ssl-key is not provided ingress will use a self-signed certificate. This parameter is specific to nginx-ingress-controller.
ingress-default-ssl-key
(string) Private key to be used by the default HTTPS server. If one of the flag ingress-default-ssl-certificate or ingress-default-ssl-key is not provided ingress will use a self-signed certificate. This parameter is specific to nginx-ingress-controller.
ingress-ssl-chain-completion
(boolean) Enable chain completion for TLS certificates used by the nginx ingress controller. Set this to true if you would like the ingress controller to attempt auto-retrieval of intermediate certificates. The default (false) is recommended for all production kubernetes installations, and any environment which does not have outbound Internet access.
ingress-ssl-passthrough
(boolean) Enable ssl passthrough on ingress server. This allows passing the ssl connection through to the workloads and not terminating it at the ingress controller.
ingress-use-forwarded-headers
(boolean) If true, NGINX passes the incoming X-Forwarded-* headers to upstreams. Use this option when NGINX is behind another L7 proxy / load balancer that is setting these headers. If false, NGINX ignores incoming X-Forwarded-* headers, filling them with the request information it sees. Use this option if NGINX is exposed directly to the internet, or it's behind a L3/packet-based load balancer that doesn't alter the source IP in the packets. Reference: https://github.com/kubernetes/ingress-nginx/blob/a9c706be12a8be418c49ab1f60a02f52f9b14e55/ docs/user-guide/nginx-configuration/configmap.md#use-forwarded-headers.
kubelet-extra-args
(string) Space separated list of flags and key=value pairs that will be passed as arguments to kubelet. For example a value like this: runtime-config=batch/v2alpha1=true profiling=true will result in kubelet being run with the following options: --runtime-config=batch/v2alpha1=true --profiling=true Note: As of Kubernetes 1.10.x, many of Kubelet's args have been deprecated, and can be set with kubelet-extra-config instead.
kubelet-extra-config
(string) Extra configuration to be passed to kubelet. Any values specified in this config will be merged into a KubeletConfiguration file that is passed to the kubelet service via the --config flag. This can be used to override values provided by the charm. Requires Kubernetes 1.10+. The value for this config must be a YAML mapping that can be safely merged with a KubeletConfiguration file. For example: {evictionHard: {memory.available: 200Mi}} For more information about KubeletConfiguration, see upstream docs: https://kubernetes.io/docs/tasks/administer-cluster/kubelet-config-file/
{}
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.
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
nagios_servicegroups
(string) A comma-separated list of nagios servicegroups. If left empty, the nagios_context will be used as the servicegroup
nginx-image
(string) Docker image to use for the nginx ingress controller. Auto will select an image based on architecture.
auto
proxy-extra-args
(string) Space separated list of flags and key=value pairs that will be passed as arguments to kube-proxy. For example a value like this: runtime-config=batch/v2alpha1=true profiling=true will result in kube-apiserver being run with the following options: --runtime-config=batch/v2alpha1=true --profiling=true
require-manual-upgrade
(boolean) When true, worker services will not be upgraded until the user triggers it manually by running the upgrade action.
True
snap_proxy
(string) DEPRECATED. Use snap-http-proxy and snap-https-proxy model configuration settings. HTTP/HTTPS web proxy for Snappy to use when accessing the snap store.
snap_proxy_url
(string) DEPRECATED. Use snap-store-proxy model configuration setting. The address of a Snap Store Proxy to use for snaps e.g. http://snap-proxy.example.com
snapd_refresh
(string) How often snapd handles updates for installed snaps. Setting an empty string will check 4x per day. Set to "max" to delay the refresh as long as possible. You may also set a custom string as described in the 'refresh.timer' section here: https://forum.snapcraft.io/t/system-options/87
max
sysctl
(string) YAML formatted associative array of sysctl values, e.g.: '{kernel.pid_max : 4194303 }'. Note that kube-proxy handles the conntrack settings. The proper way to alter them is to use the proxy-extra-args config to set them, e.g.: juju config kubernetes-master proxy-extra-args="conntrack-min=1000000 conntrack-max-per-core=250000" juju config kubernetes-worker proxy-extra-args="conntrack-min=1000000 conntrack-max-per-core=250000" The proxy-extra-args conntrack-min and conntrack-max-per-core can be set to 0 to ignore kube-proxy's settings and use the sysctl settings instead. Note the fundamental difference between the setting of conntrack-max-per-core vs nf_conntrack_max.
{ net.ipv4.conf.all.forwarding : 1, net.ipv4.neigh.default.gc_thresh1 : 128, net.ipv4.neigh.default.gc_thresh2 : 28672, net.ipv4.neigh.default.gc_thresh3 : 32768, net.ipv6.neigh.default.gc_thresh1 : 128, net.ipv6.neigh.default.gc_thresh2 : 28672, net.ipv6.neigh.default.gc_thresh3 : 32768, fs.inotify.max_user_instances : 8192, fs.inotify.max_user_watches : 1048576, kernel.panic : 10, kernel.panic_on_oops: 1, vm.overcommit_memory : 1 }