This document describes how to deploy kubernetes on ubuntu nodes, including 1 kubernetes master and 3 kubernetes nodes, and people uses this approach can scale to **any number of nodes** by changing some settings with ease. The original idea was heavily inspired by @jainvipin 's ubuntu single node work, which has been merge into this document.
*3 These guide is tested OK on Ubuntu 14.04 LTS 64bit server, but it can not work with Ubuntu 15 which use systemd instead of upstart and we are fixing this*
You can customize your etcd version, flannel version, k8s version by changing variable `ETCD_VERSION` , `FLANNEL_VERSION` and `K8S_VERSION` in build.sh, default etcd version is 2.0.12, flannel version is 0.4.0 and K8s version is 0.19.3.
Please make sure that there are `kube-apiserver`, `kube-controller-manager`, `kube-scheduler`, `kubelet`, `kube-proxy`, `etcd`, `etcdctl` and `flannel` in the binaries/master or binaries/minion directory.
> We used flannel here because we want to use overlay network, but please remember it is not the only choice, and it is also not a k8s' necessary dependence. Actually you can just build up k8s cluster natively, or use flannel, Open vSwitch or any other SDN tool you like, we just choose flannel here as a example.
The first variable `nodes` defines all your cluster nodes, MASTER node comes first and separated with blank space like `<user_1@ip_1> <user_2@ip_2> <user_3@ip_3> `
Then the `roles ` variable defines the role of above machine in the same order, "ai" stands for machine acts as both master and node, "a" stands for master, "i" stands for node. So they are just defined the k8s cluster as the table above described.
The `SERVICE_CLUSTER_IP_RANGE` variable defines the kubernetes service IP range. Please make sure that you do have a valid private ip range defined here, because some IaaS provider may reserve private ips. You can use below three private network range according to rfc1918. Besides you'd better not choose the one that conflicts with your own private network range.
After all the above variable being set correctly. We can use below command in cluster/ directory to bring up the whole cluster.
`$ KUBERNETES_PROVIDER=ubuntu ./kube-up.sh`
The scripts is automatically scp binaries and config files to all the machines and start the k8s service on them. The only thing you need to do is to type the sudo password when promoted. The current machine name is shown below like. So you will not type in the wrong password.
You can also use `kubectl` command to see if the newly created k8s is working correctly. The `kubectl` binary is under the `cluster/ubuntu/binaries` directory. You can move it into your PATH. Then you can use the below command smoothly.
We are working on these features which we'd like to let everybody know:
1. Run Kubernetes binaries in Docker using [kube-in-docker](https://github.com/ZJU-SEL/kube-in-docker/tree/baremetal-kube), to eliminate OS-distro differences.
2. Tearing Down scripts: clear and re-create the whole stack by one click.
