Setting up Kubernetes with Juju
Out of the box it comes with the following components on 9 machines:
- Kubernetes (automated deployment, operations, and scaling)
- Three node Kubernetes cluster with one master and two worker nodes.
- TLS used for communication between units for security.
- Flannel Software Defined Network (SDN) plugin
- A load balancer for HA kubernetes-master (Experimental)
- Optional Ingress Controller (on worker)
- Optional Dashboard addon (on master) including Heapster for cluster monitoring
- EasyRSA
- Performs the role of a certificate authority serving self signed certificates to the requesting units of the cluster.
- ETCD (distributed key value store)
- Three unit cluster for reliability.
The Juju Kubernetes work is curated by a dedicated team of community members, let us know how we are doing. If you find any problems please open an issue on our tracker so we can find them.
Support Level
| IaaS Provider | Config. Mgmt | OS | Networking | Docs | Conforms | Support Level |
|---|---|---|---|---|---|---|
| Amazon Web Services (AWS) | Juju | Ubuntu | flannel, calico* | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| OpenStack | Juju | Ubuntu | flannel, calico | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| Microsoft Azure | Juju | Ubuntu | flannel | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| Google Compute Engine (GCE) | Juju | Ubuntu | flannel, calico | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| Joyent | Juju | Ubuntu | flannel | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| Rackspace | Juju | Ubuntu | flannel | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| VMWare vSphere | Juju | Ubuntu | flannel, calico | docs | Commercial, Community ( @mbruzek, @chuckbutler ) | |
| Bare Metal (MAAS) | Juju | Ubuntu | flannel, calico | docs | Commercial, Community ( @mbruzek, @chuckbutler ) |
For support level information on all solutions, see the Table of solutions chart.
Ubuntu 16.04 introduced the Canonical Distribution of Kubernetes, a pure upstream distribution of Kubernetes designed for production usage. This page shows you how to deploy a cluster.
- Support Level
- Before you begin
- Prerequisites
- Launch a Kubernetes cluster
- Monitor deployment
- Interacting with the cluster
- Scale up cluster
- Scale out cluster
- Tear down cluster
- More Info
Before you begin
Prerequisites
- A working Juju client; this does not have to be a Linux machine, it can also be Windows or OSX.
- A supported cloud.
- Bare Metal deployments are supported via MAAS. Refer to the MAAS documentation for configuration instructions.
- OpenStack deployments are currently only tested on Icehouse and newer.
- Network access to the following domains
- *.jujucharms.com
- gcr.io
- github.com
- Access to an Ubuntu mirror (public or private)
Configure Juju to use your cloud provider
Deployment of the cluster is supported on a wide variety of public clouds, private OpenStack clouds, or raw bare metal clusters. Bare metal deployments are supported via MAAS.
After deciding which cloud to deploy to, follow the cloud setup page to configure deploying to that cloud.
Load your cloud credentials for each cloud provider you would like to use.
In this example
juju add-credential aws
credential name: my_credentials
select auth-type [userpass, oauth, etc]: userpass
enter username: jorge
enter password: *******
You can also just auto load credentials for popular clouds with the juju autoload-credentials command, which will auto import your credentials from the default files and environment variables for each cloud.
Next we need to bootstrap a controller to manage the cluster. You need to define the cloud you want to bootstrap on, the region, and then any name for your controller node:
juju update-clouds # This command ensures all the latest regions are up to date on your client
juju bootstrap aws/us-east-2
or, another example, this time on Azure:
juju bootstrap azure/centralus
You will need a controller node for each cloud or region you are deploying to. See the controller documentation for more information.
Note that each controller can host multiple Kubernetes clusters in a given cloud or region.
Launch a Kubernetes cluster
The following command will deploy the initial 9-node starter cluster. The speed of execution is very dependent of the performance of the cloud you’re deploying to:
juju deploy canonical-kubernetes
After this command executes the cloud will then launch instances and begin the deployment process.
Monitor deployment
The juju status command provides information about each unit in the cluster. Use the watch -c juju status --color command to get a real-time view of the cluster as it deploys. When all the states are green and “Idle”, the cluster is ready to be used:
juju status
Output:
Model Controller Cloud/Region Version
default aws-us-east-2 aws/us-east-2 2.0.1
App Version Status Scale Charm Store Rev OS Notes
easyrsa 3.0.1 active 1 easyrsa jujucharms 3 ubuntu
etcd 3.1.2 active 3 etcd jujucharms 14 ubuntu
flannel 0.6.1 maintenance 4 flannel jujucharms 5 ubuntu
kubeapi-load-balancer 1.10.0 active 1 kubeapi-load-balancer jujucharms 3 ubuntu exposed
kubernetes-master 1.6.1 active 1 kubernetes-master jujucharms 6 ubuntu
kubernetes-worker 1.6.1 active 3 kubernetes-worker jujucharms 8 ubuntu exposed
topbeat active 3 topbeat jujucharms 5 ubuntu
Unit Workload Agent Machine Public address Ports Message
easyrsa/0* active idle 0 52.15.95.92 Certificate Authority connected.
etcd/0 active idle 3 52.15.79.127 2379/tcp Healthy with 3 known peers.
etcd/1* active idle 4 52.15.111.66 2379/tcp Healthy with 3 known peers. (leader)
etcd/2 active idle 5 52.15.144.25 2379/tcp Healthy with 3 known peers.
kubeapi-load-balancer/0* active idle 7 52.15.84.179 443/tcp Loadbalancer ready.
kubernetes-master/0* active idle 8 52.15.106.225 6443/tcp Kubernetes master services ready.
flannel/3 active idle 52.15.106.225 Flannel subnet 10.1.48.1/24
kubernetes-worker/0* active idle 9 52.15.153.246 Kubernetes worker running.
flannel/2 active idle 52.15.153.246 Flannel subnet 10.1.53.1/24
kubernetes-worker/1 active idle 10 52.15.52.103 Kubernetes worker running.
flannel/0* active idle 52.15.52.103 Flannel subnet 10.1.31.1/24
kubernetes-worker/2 active idle 11 52.15.104.181 Kubernetes worker running.
flannel/1 active idle 52.15.104.181 Flannel subnet 10.1.83.1/24
Machine State DNS Inst id Series AZ
0 started 52.15.95.92 i-06e66414008eca61c xenial us-east-2c
3 started 52.15.79.127 i-0038186d2c5103739 xenial us-east-2b
4 started 52.15.111.66 i-0ac66c86a8ec93b18 xenial us-east-2a
5 started 52.15.144.25 i-078cfe79313d598c9 xenial us-east-2c
7 started 52.15.84.179 i-00fd70321a51b658b xenial us-east-2c
8 started 52.15.106.225 i-0109a5fc942c53ed7 xenial us-east-2b
9 started 52.15.153.246 i-0ab63e34959cace8d xenial us-east-2b
10 started 52.15.52.103 i-0108a8cc0978954b5 xenial us-east-2a
11 started 52.15.104.181 i-0f5562571c649f0f2 xenial us-east-2c
Interacting with the cluster
After the cluster is deployed you may assume control over the cluster from any kubernetes-master, or kubernetes-worker node.
First you need to download the credentials and client application to your local workstation:
Create the kubectl config directory.
mkdir -p ~/.kube
Copy the kubeconfig file to the default location.
juju scp kubernetes-master/0:config ~/.kube/config
Fetch a binary for the architecture you have deployed. If your client is a
different architecture you will need to get the appropriate kubectl binary
through other means. In this example we copy kubectl to ~/bin for convenience,
by default this should be in your $PATH.
mkdir -p ~/bin
juju scp kubernetes-master/0:kubectl ~/bin/kubectl
Query the cluster:
kubectl cluster-info
Output:
Kubernetes master is running at https://52.15.104.227:443
Heapster is running at https://52.15.104.227:443/api/v1/namespaces/kube-system/services/heapster/proxy
KubeDNS is running at https://52.15.104.227:443/api/v1/namespaces/kube-system/services/kube-dns/proxy
Grafana is running at https://52.15.104.227:443/api/v1/namespaces/kube-system/services/monitoring-grafana/proxy
InfluxDB is running at https://52.15.104.227:443/api/v1/namespaces/kube-system/services/monitoring-influxdb/proxy
Congratulations, you’ve now set up a Kubernetes cluster!
Scale up cluster
Want larger Kubernetes nodes? It is easy to request different sizes of cloud
resources from Juju by using constraints. You can increase the amount of
CPU or memory (RAM) in any of the systems requested by Juju. This allows you
to fine tune the Kubernetes cluster to fit your workload. Use flags on the
bootstrap command or as a separate juju constraints command. Look to the
Juju documentation for machine
details.
Scale out cluster
Need more workers? We just add more units:
juju add-unit kubernetes-worker
Or multiple units at one time:
juju add-unit -n3 kubernetes-worker
You can also ask for specific instance types or other machine-specific constraints. See the constraints documentation for more information. Here are some examples, note that generic constraints such as cores and mem are more portable between clouds. In this case we’ll ask for a specific instance type from AWS:
juju set-constraints kubernetes-worker instance-type=c4.large
juju add-unit kubernetes-worker
You can also scale the etcd charm for more fault tolerant key/value storage:
juju add-unit -n3 etcd
It is strongly recommended to run an odd number of units for quorum.
Tear down cluster
If you want stop the servers you can destroy the Juju model or the
controller. Use the juju switch command to get the current controller name:
juju switch
juju destroy-controller $controllername --destroy-all-models
This will shutdown and terminate all running instances on that cloud.
More Info
The Ubuntu Kubernetes deployment uses open-source operations, or operations as code, known as charms. These charms are assembled from layers which keeps the code smaller and more focused on the operations of just Kubernetes and its components.
The Kubernetes layer and bundles can be found in the kubernetes
project on github.com:
Feature requests, bug reports, pull requests or any feedback would be much appreciated.