rke
Rancher Kubernetes Engine, an extremely simple, lightning fast Kubernetes installer that works everywhere.
Download
Please check the releases page.
Requirements
- Docker versions 1.12.6, 1.13.1, or 17.03 should be installed for Kubernetes 1.8.
- OpenSSH 7.0+ must be installed on each node for stream local forwarding to work.
- The SSH user used for node access must be a member of the
docker
group:
usermod -aG docker <user_name>
- Ports 6443, 2379, and 2380 should be opened between cluster nodes.
Getting Started
Standing up a Kubernetes is as simple as creating a cluster.yml
configuration file and and running the command:
./rke up --config cluster.yaml
Full cluster.yaml
example
You can view full sample of cluster.yml here.
Minimal cluster.yaml
example
nodes:
- address: 1.1.1.1
user: ubuntu
role: [controlplane,worker,etcd]
services:
etcd:
image: quay.io/coreos/etcd:latest
kube-api:
image: rancher/k8s:v1.8.3-rancher2
kube-controller:
image: rancher/k8s:v1.8.3-rancher2
scheduler:
image: rancher/k8s:v1.8.3-rancher2
kubelet:
image: rancher/k8s:v1.8.3-rancher2
kubeproxy:
image: rancher/k8s:v1.8.3-rancher2
Network Plugins
RKE supports the following network plugins:
- Flannel
- Calico
- Cannal
- Weave
To use specific network plugin configure cluster.yml
to include:
network:
plugin: flannel
Network Options
There are extra options that can be specified for each network plugin:
Flannel
- flannel_image: Flannel daemon Docker image
- flannel_cni_image: Flannel CNI binary installer Docker image
- flannel_iface: Interface to use for inter-host communication
Calico
- calico_node_image: Calico Daemon Docker image
- calico_cni_image: Calico CNI binary installer Docker image
- calico_controllers_image: Calico Controller Docker image
- calicoctl_image: Calicoctl tool Docker image
- calico_cloud_provider: Cloud provider where Calico will operate, current available value is:
aws
Cannal
- canal_node_image: Cannal Node Docker image
- canal_cni_image: Cannal CNI binary installer Docker image
- canal_flannel_image: Cannal Flannel Docker image
Weave
- weave_node_image: Weave Node Docker image
- weave_cni_image: Weave CNI binary installer Docker image
Addons
RKE support pluggable addons on cluster bootstrap, user can specify the addon yaml in the cluster.yml file, and when running
rke up --config cluster.yml
RKE will deploy the addons yaml after the cluster starts, RKE first uploads this yaml file as a configmap in kubernetes cluster and then run a kubernetes job that mounts this config map and deploy the addons.
Note that RKE doesn't support yet removal of the addons, so once they are deployed the first time you can't change them using rke
To start using addons use addons:
option in the cluster.yml
file for example:
addons: |-
---
apiVersion: v1
kind: Pod
metadata:
name: my-nginx
namespace: default
spec:
containers:
- name: my-nginx
image: nginx
ports:
- containerPort: 80
Note that we are using |-
because the addons option is a multi line string option, where you can specify multiple yaml files and separate them with ---
High Availability
RKE is HA ready, you can specify more than one controlplane host in the cluster.yml
file, and rke will deploy master components on all of them, the kubelets are configured to connect to 127.0.0.1:6443
by default which is the address of nginx-proxy
service that proxy requests to all master nodes.
to start an HA cluster, just specify more than one host with role controlplane
, and start the cluster normally.
Adding/Removing Nodes
RKE support adding/removing nodes for worker and controlplane hosts, in order to add additional nodes you will only need to update the cluster.yml
file with additional nodes and run rke up
with the same file.
To remove nodes just remove them from the hosts list in the cluster configuration file cluster.yml
, and re run rke up
command.
Cluster Remove
RKE support rke remove
command, the command does the following:
- Connect to each host and remove the kubernetes services deployed on it.
- Clean each host from the directories left by the services:
- /etc/kubernetes/ssl
- /var/lib/etcd
- /etc/cni
- /opt/cni
- /var/run/calico
Note that this command is irreversible and will destroy the kubernetes cluster entirely.
Cluster Upgrade
RKE support kubernetes cluster upgrade through changing the image version of services, in order to do that change the image option for each services, for example:
image: rancher/k8s:v1.8.2-rancher1
TO
image: rancher/k8s:v1.8.3-rancher2
And then run:
rke up --config cluster.yml
RKE will first look for the local .kube_config_cluster.yml
and then tries to upgrade each service to the latest image.
Note that rollback isn't supported in RKE and may lead to unxpected results
RKE Config
RKE support command rke config
which generates a cluster config template for the user, to start using this command just write:
rke config --name mycluster.yml
RKE will ask some questions around the cluster file like number of the hosts, ips, ssh users, etc, --empty
option will generate an empty cluster.yml file, also if you just want to print on the screen and not save it in a file you can use --print
.
More details
More information about RKE design, configuration and usage can be found in this blog post.
License
Copyright (c) 2017 Rancher Labs, Inc.
Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.