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WARNING WARNING WARNING WARNING WARNING

PLEASE NOTE: This document applies to the HEAD of the source tree

If you are using a released version of Kubernetes, you should refer to the docs that go with that version.

The latest 1.0.x release of this document can be found [here](http://releases.k8s.io/release-1.0/docs/getting-started-guides/ubuntu-calico.md).

Documentation for other releases can be found at releases.k8s.io.

Kubernetes Deployment On Bare-metal Ubuntu Nodes with Calico Networking

Introduction

This document describes how to deploy Kubernetes on ubuntu bare metal nodes with Calico Networking plugin. See projectcalico.org for more information on what Calico is, and the calicoctl github for more information on the command-line tool, calicoctl.

This guide will set up a simple Kubernetes cluster with a master and two nodes. We will start the following processes with systemd:

On the Master:

  • etcd
  • kube-apiserver
  • kube-controller-manager
  • kube-scheduler
  • calico-node

On each Node:

  • kube-proxy
  • kube-kubelet
  • calico-node

Prerequisites

  1. This guide uses systemd and thus uses Ubuntu 15.04 which supports systemd natively.
  2. All Kubernetes nodes should have the latest docker stable version installed. At the time of writing, that is Docker 1.7.0.
  3. All hosts should be able to communicate with each other, as well as the internet, to download the necessary files.
  4. This demo assumes that none of the hosts have been configured with any Kubernetes or Calico software yet.

Setup Master

First, get the sample configurations for this tutorial

wget https://github.com/Metaswitch/calico-kubernetes-ubuntu-demo/archive/master.tar.gz
tar -xvf master.tar.gz

Setup environment variables for systemd services on Master

Many of the sample systemd services provided rely on environment variables on a per-node basis. Here we'll edit those environment variables and move them into place.

1.) Copy the network-environment-template from the master directory for editing.

cp calico-kubernetes-ubuntu-demo-master/master/network-environment-template network-environment

2.) Edit network-environment to represent your current host's settings.

3.) Move the network-environment into /etc

sudo mv -f network-environment /etc

Install Kubernetes on Master

1.) Build & Install Kubernetes binaries

# Get the Kubernetes Source
wget https://github.com/GoogleCloudPlatform/kubernetes/releases/download/v0.20.2/kubernetes.tar.gz

# Untar it
tar -xf kubernetes.tar.gz
tar -xf kubernetes/server/kubernetes-server-linux-amd64.tar.gz
kubernetes/cluster/ubuntu/build.sh

# Add binaries to /usr/bin
sudo cp -f binaries/master/* /usr/bin
sudo cp -f binaries/kubectl /usr/bin

2.) Install the sample systemd processes settings for launching kubernetes services

sudo cp -f calico-kubernetes-ubuntu-demo-master/master/*.service /etc/systemd
sudo systemctl enable /etc/systemd/etcd.service
sudo systemctl enable /etc/systemd/kube-apiserver.service
sudo systemctl enable /etc/systemd/kube-controller-manager.service
sudo systemctl enable /etc/systemd/kube-scheduler.service

3.) Launch the processes.

sudo systemctl start etcd.service
sudo systemctl start kube-apiserver.service
sudo systemctl start kube-controller-manager.service
sudo systemctl start kube-scheduler.service

You may want to consider checking their status after to ensure everything is running.

Install Calico on Master

In order to allow the master to route to pods on our nodes, we will launch the calico-node daemon on our master. This will allow it to learn routes over BGP from the other calico-node daemons in the cluster. The docker daemon should already be running before calico is started.

# Install the calicoctl binary, which will be used to launch calico
wget https://github.com/Metaswitch/calico-docker/releases/download/v0.5.1/calicoctl
chmod +x calicoctl
sudo cp -f calicoctl /usr/bin

# Install and start the calico service
sudo cp -f calico-kubernetes-ubuntu-demo-master/master/calico-node.service /etc/systemd
sudo systemctl enable /etc/systemd/calico-node.service
sudo systemctl start calico-node.service

Note: calico-node may take a few minutes on first boot while it downloads the calico-node docker image.

Setup Nodes

Perform these steps once on each node, ensuring you appropriately set the environment variables on each node

Setup environment variables for systemd services on the Node

1.) Get the sample configurations for this tutorial

wget https://github.com/Metaswitch/calico-kubernetes-ubuntu-demo/archive/master.tar.gz
tar -xvf master.tar.gz

2.) Copy the network-environment-template from the node directory

cp calico-kubernetes-ubuntu-demo-master/node/network-environment-template network-environment

3.) Edit network-environment to represent your current host's settings.

4.) Move netework-environment into /etc

sudo mv -f network-environment /etc

Configure Docker on the Node

Create the veth

Instead of using docker's default interface (docker0), we will configure a new one to use desired IP ranges

sudo brctl addbr cbr0
sudo ifconfig cbr0 up
sudo ifconfig cbr0 <IP>/24

Replace <IP> with the subnet for this host's containers. Example topology:

Node cbr0 IP
node-1 192.168.1.1/24
node-2 192.168.2.1/24
node-X 192.168.X.1/24

Start docker on cbr0

The Docker daemon must be started and told to use the already configured cbr0 instead of using the usual docker0, as well as disabling ip-masquerading and modification of the ip-tables.

1.) Edit the ubuntu-15.04 docker.service for systemd at: /lib/systemd/system/docker.service

2.) Find the line that reads ExecStart=/usr/bin/docker -d -H fd:// and append the following flags: --bridge=cbr0 --iptables=false --ip-masq=false

3.) Reload systemctl with sudo systemctl daemon-reload

4.) Restart docker with with sudo systemctl restart docker

Install Calico on the Node

1.) Install Calico

# Get the calicoctl binary
wget https://github.com/Metaswitch/calico-docker/releases/download/v0.5.1/calicoctl
chmod +x calicoctl
sudo cp -f calicoctl /usr/bin

# Start calico on this node
sudo cp calico-kubernetes-ubuntu-demo-master/node/calico-node.service /etc/systemd
sudo systemctl enable /etc/systemd/calico-node.service
sudo systemctl start calico-node.service

The calico-node service will automatically get the kubernetes-calico plugin binary and install it on the host system.

2.) Use calicoctl to add an IP pool. We must specify the IP and port that the master's etcd is listening on. NOTE: This step only needs to be performed once per Kubernetes deployment, as it covers all the node's IP ranges.

ETCD_AUTHORITY=<MASTER_IP>:4001 calicoctl pool add 192.168.0.0/16

Install Kubernetes on the Node

1.) Build & Install Kubernetes binaries

# Get the Kubernetes Source
wget https://github.com/GoogleCloudPlatform/kubernetes/releases/download/v0.20.2/kubernetes.tar.gz

# Untar it
tar -xf kubernetes.tar.gz
tar -xf kubernetes/server/kubernetes-server-linux-amd64.tar.gz
kubernetes/cluster/ubuntu/build.sh

# Add binaries to /usr/bin
sudo cp -f binaries/minion/* /usr/bin

2.) Install and launch the sample systemd processes settings for launching Kubernetes services

sudo cp calico-kubernetes-ubuntu-demo-master/node/kube-proxy.service /etc/systemd/
sudo cp calico-kubernetes-ubuntu-demo-master/node/kube-kubelet.service /etc/systemd/
sudo systemctl enable /etc/systemd/kube-proxy.service
sudo systemctl enable /etc/systemd/kube-kubelet.service
sudo systemctl start kube-proxy.service
sudo systemctl start kube-kubelet.service

You may want to consider checking their status after to ensure everything is running

Launch other Services With Calico-Kubernetes

At this point, you have a fully functioning cluster running on kubernetes with a master and 2 nodes networked with Calico. You can now follow any of the standard documentation to set up other services on your cluster.

Connectivity to outside the cluster

With this sample configuration, because the containers have private 192.168.0.0/16 IPs, you will need NAT to allow connectivity between containers and the internet. However, in a full datacenter deployment, NAT is not always necessary, since Calico can peer with the border routers over BGP.

NAT on the nodes

The simplest method for enabling connectivity from containers to the internet is to use an iptables masquerade rule. This is the standard mechanism recommended in the Kubernetes GCE environment.

We need to NAT traffic that has a destination outside of the cluster. Internal traffic includes the master/nodes, and the container IP pools. Assuming that the master and nodes are in the 172.25.0.0/24 subnet, the cbr0 IP ranges are all in the 192.168.0.0/16 network, and the nodes use the interface eth0 for external connectivity, a suitable masquerade chain would look like this:

sudo iptables -t nat -N KUBE-OUTBOUND-NAT
sudo iptables -t nat -A KUBE-OUTBOUND-NAT -d 192.168.0.0/16 -o eth0 -j RETURN
sudo iptables -t nat -A KUBE-OUTBOUND-NAT -d 172.25.0.0/24 -o eth0 -j RETURN
sudo iptables -t nat -A KUBE-OUTBOUND-NAT -j MASQUERADE
sudo iptables -t nat -A POSTROUTING -j KUBE-OUTBOUND-NAT

This chain should be applied on the master and all nodes. In production, these rules should be persisted, e.g. with iptables-persistent.

NAT at the border router

In a datacenter environment, it is recommended to configure Calico to peer with the border routers over BGP. This means that the container IPs will be routable anywhere in the datacenter, and so NAT is not needed on the nodes (though it may be enabled at the datacenter edge to allow outbound-only internet connectivity).

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