773 lines
		
	
	
		
			31 KiB
		
	
	
	
		
			Markdown
		
	
	
	
			
		
		
	
	
			773 lines
		
	
	
		
			31 KiB
		
	
	
	
		
			Markdown
		
	
	
	
<!-- BEGIN MUNGE: UNVERSIONED_WARNING -->
 | 
						|
 | 
						|
<!-- BEGIN STRIP_FOR_RELEASE -->
 | 
						|
 | 
						|
<h1>*** PLEASE NOTE: This document applies to the HEAD of the source
 | 
						|
tree only. If you are using a released version of Kubernetes, you almost
 | 
						|
certainly want the docs that go with that version.</h1>
 | 
						|
 | 
						|
<strong>Documentation for specific releases can be found at
 | 
						|
[releases.k8s.io](http://releases.k8s.io).</strong>
 | 
						|
 | 
						|
<!-- END STRIP_FOR_RELEASE -->
 | 
						|
 | 
						|
<!-- END MUNGE: UNVERSIONED_WARNING -->
 | 
						|
Getting started from Scratch
 | 
						|
----------------------------
 | 
						|
 | 
						|
This guide is for people who want to craft a custom Kubernetes cluster.  If you
 | 
						|
can find an existing Getting Started Guide that meets your needs on [this
 | 
						|
list](README.md), then we recommend using it, as you will be able to benefit
 | 
						|
from the experience of others.  However, if you have specific IaaS, networking,
 | 
						|
configuration management, or operating system requirements not met by any of
 | 
						|
those guides, then this guide will provide an outline of the steps you need to
 | 
						|
take.  Note that it requires considerably more effort than using one of the
 | 
						|
pre-defined guides.
 | 
						|
 | 
						|
This guide is also useful for those wanting to understand at a high level some of the
 | 
						|
steps that existing cluster setup scripts are making.
 | 
						|
 | 
						|
**Table of Contents**
 | 
						|
 | 
						|
<!-- BEGIN MUNGE: GENERATED_TOC -->
 | 
						|
  - [Designing and Preparing](#designing-and-preparing)
 | 
						|
    - [Learning](#learning)
 | 
						|
    - [Cloud Provider](#cloud-provider)
 | 
						|
    - [Nodes](#nodes)
 | 
						|
    - [Network](#network)
 | 
						|
    - [Cluster Naming](#cluster-naming)
 | 
						|
    - [Software Binaries](#software-binaries)
 | 
						|
      - [Downloading and Extracting Kubernetes Binaries](#downloading-and-extracting-kubernetes-binaries)
 | 
						|
      - [Selecting Images](#selecting-images)
 | 
						|
    - [Security Models](#security-models)
 | 
						|
      - [Preparing Certs](#preparing-certs)
 | 
						|
      - [Preparing Credentials](#preparing-credentials)
 | 
						|
  - [Configuring and Installing Base Software on Nodes](#configuring-and-installing-base-software-on-nodes)
 | 
						|
    - [Docker](#docker)
 | 
						|
    - [rkt](#rkt)
 | 
						|
    - [kubelet](#kubelet)
 | 
						|
    - [kube-proxy](#kube-proxy)
 | 
						|
    - [Networking](#networking)
 | 
						|
 | 
						|
<!-- END MUNGE: GENERATED_TOC -->
 | 
						|
 | 
						|
## Designing and Preparing
 | 
						|
 | 
						|
### Learning 
 | 
						|
  1. You should be familiar with using Kubernetes already.  We suggest you set
 | 
						|
    up a temporary cluster by following one of the other Getting Started Guides.
 | 
						|
    This will help you become familiar with the CLI ([kubectl](../user-guide/kubectl/kubectl.md)) and concepts ([pods](../pods.md), [services](../services.md), etc.) first.
 | 
						|
  1. You should have `kubectl` installed on your desktop.  This will happen as a side
 | 
						|
    effect of completing one of the other Getting Started Guides.
 | 
						|
 | 
						|
### Cloud Provider
 | 
						|
Kubernetes has the concept of a Cloud Provider, which is a module which provides
 | 
						|
an interface for managing TCP Load Balancers, Nodes (Instances) and Networking Routes.
 | 
						|
The interface is defined in `pkg/cloudprovider/cloud.go`.  It is possible to
 | 
						|
create a custom cluster without implementing a cloud provider (for example if using
 | 
						|
bare-metal), and not all parts of the interface need to be implemented, depending
 | 
						|
on how flags are set on various components. 
 | 
						|
 | 
						|
### Nodes
 | 
						|
- You can use virtual or physical machines.
 | 
						|
- While you can build a cluster with 1 machine, in order to run all the examples and tests you
 | 
						|
  need at least 4 nodes.
 | 
						|
- Many Getting-started-guides make a distinction between the master node and regular nodes.  This
 | 
						|
  is not strictly necessary.
 | 
						|
- Nodes will need to run some version of Linux with the x86_64 architecture.  It may be possible
 | 
						|
  to run on other OSes and Architectures, but this guide does not try to assist with that.
 | 
						|
- Apiserver and etcd together are fine on a machine with 1 core and 1GB RAM for clusters with 10s of nodes.
 | 
						|
  Larger or more active clusters may benefit from more cores.
 | 
						|
- Other nodes can have any reasonable amount of memory and any number of cores.  They need not
 | 
						|
  have identical configurations.
 | 
						|
 | 
						|
### Network
 | 
						|
Kubernetes has a distinctive [networking model](../networking.md).
 | 
						|
 | 
						|
Kubernetes allocates an IP address to each pod.  When creating a cluster, you
 | 
						|
need to allocate a block of IPs for Kubernetes to use as Pod IPs.  The simplest
 | 
						|
approach is to allocate a different block of IPs to each node in the cluster as
 | 
						|
the node is added.  A process in one pod should be able to communicate with
 | 
						|
another pod using the IP of the second pod.  This connectivity can be
 | 
						|
accomplished in two ways:
 | 
						|
- Configure network to route Pod IPs
 | 
						|
  - Harder to setup from scratch.
 | 
						|
  - Google Compute Engine ([GCE](gce.md)) and [AWS](aws.md) guides use this approach.
 | 
						|
  - Need to make the Pod IPs routable by programming routers, switches, etc.
 | 
						|
  - Can be configured external to kubernetes, or can implement in the "Routes" interface of a Cloud Provider module.
 | 
						|
  - Generally highest performance.
 | 
						|
- Create an Overlay network
 | 
						|
  - Easier to setup
 | 
						|
  - Traffic is encapsulated, so per-pod IPs are routable.
 | 
						|
  - Examples:
 | 
						|
    - [Flannel](https://github.com/coreos/flannel)
 | 
						|
    - [Weave](http://weave.works/)
 | 
						|
    - [Open vSwitch (OVS)](http://openvswitch.org/)
 | 
						|
  - Does not require "Routes" portion of Cloud Provider module.
 | 
						|
  - Reduced performance (exactly how much depends on your solution).
 | 
						|
 | 
						|
You need to select an address range for the Pod IPs.
 | 
						|
- Various approaches:
 | 
						|
  - GCE: each project has its own `10.0.0.0/8`.  Carve off a `/16` for each
 | 
						|
    Kubernetes cluster from that space, which leaves room for several clusters.
 | 
						|
    Each node gets a further subdivision of this space.
 | 
						|
  - AWS: use one VPC for whole organization, carve off a chunk for each
 | 
						|
    cluster, or use different VPC for different clusters.
 | 
						|
  - IPv6 is not supported yet.
 | 
						|
- Allocate one CIDR subnet for each node's PodIPs, or a single large CIDR
 | 
						|
  from which smaller CIDRs are automatically allocated to each node (if nodes
 | 
						|
  are dynamically added).
 | 
						|
  - You need max-pods-per-node * max-number-of-nodes IPs in total. A `/24` per
 | 
						|
    node supports 254 pods per machine and is a common choice.  If IPs are
 | 
						|
    scarce, a `/26` (62 pods per machine) or even a `/27` (30 pods) may be sufficient.
 | 
						|
  - e.g. use `10.10.0.0/16` as the range for the cluster, with up to 256 nodes
 | 
						|
    using `10.10.0.0/24` through `10.10.255.0/24`, respectively.
 | 
						|
  - Need to make these routable or connect with overlay.
 | 
						|
 | 
						|
Kubernetes also allocates an IP to each [service](../services.md).  However,
 | 
						|
service IPs do not necessarily need to be routable.  The kube-proxy takes care
 | 
						|
of translating Service IPs to Pod IPs before traffic leaves the node.  You do
 | 
						|
need to Allocate a block of IPs for services.  Call this
 | 
						|
`SERVICE_CLUSTER_IP_RANGE`.  For example, you could set
 | 
						|
`SERVICE_CLUSTER_IP_RANGE="10.0.0.0/16"`, allowing 65534 distinct services to
 | 
						|
be active at once.  Note that you can grow the end of this range, but you
 | 
						|
cannot move it without disrupting the services and pods that already use it.
 | 
						|
 | 
						|
Also, you need to pick a static IP for master node.
 | 
						|
- Call this `MASTER_IP`.
 | 
						|
- Open any firewalls to allow access to the apiserver ports 80 and/or 443.
 | 
						|
- Enable ipv4 forwarding sysctl, `net.ipv4.ip_forward = 1`
 | 
						|
 | 
						|
### Cluster Naming
 | 
						|
 | 
						|
You should pick a name for your cluster.  Pick a short name for each cluster
 | 
						|
which is unique from future cluster names. This will be used in several ways:
 | 
						|
  - by kubectl to distinguish between various clusters you have access to.  You will probably want a
 | 
						|
    second one sometime later, such as for testing new Kubernetes releases, running in a different
 | 
						|
region of the world, etc.
 | 
						|
  - Kubernetes clusters can create cloud provider resources (e.g. AWS ELBs) and different clusters
 | 
						|
    need to distinguish which resources each created.  Call this `CLUSTERNAME`.
 | 
						|
 | 
						|
### Software Binaries
 | 
						|
You will need binaries for:
 | 
						|
  - etcd
 | 
						|
  - A container runner, one of:
 | 
						|
    - docker
 | 
						|
    - rkt
 | 
						|
  - Kubernetes
 | 
						|
    - kubelet
 | 
						|
    - kube-proxy
 | 
						|
    - kube-apiserver
 | 
						|
    - kube-controller-manager
 | 
						|
    - kube-scheduler
 | 
						|
 | 
						|
#### Downloading and Extracting Kubernetes Binaries
 | 
						|
A Kubernetes binary release includes all the Kubernetes binaries as well as the supported release of etcd.
 | 
						|
You can use a Kubernetes binary release (recommended) or build your Kubernetes binaries following the instructions in the
 | 
						|
[Developer Documentation](../devel/README.md).  Only using a binary release is covered in this guide.
 | 
						|
 | 
						|
Download the [latest binary release](
 | 
						|
https://github.com/GoogleCloudPlatform/kubernetes/releases/latest) and unzip it.
 | 
						|
Then locate `./kubernetes/server/kubernetes-server-linux-amd64.tar.gz` and unzip *that*.
 | 
						|
Then, within the second set of unzipped files, locate `./kubernetes/server/bin`, which contains
 | 
						|
all the necessary binaries.
 | 
						|
 | 
						|
#### Selecting Images
 | 
						|
You will run docker, kubelet, and kube-proxy outside of a container, the same way you would run any system daemon, so
 | 
						|
you just need the bare binaries.  For etcd, kube-apiserver, kube-controller-manager, and kube-scheduler, 
 | 
						|
we recommend that you run these as containers, so you need an image to be built.
 | 
						|
 | 
						|
You have several choices for Kubernetes images:
 | 
						|
1. Use images hosted on Google Container Registry (GCR):
 | 
						|
  - e.g `gcr.io/google_containers/kube-apiserver:$TAG`, where `TAG` is the latest
 | 
						|
    release tag, which can be found on the [latest releases page](
 | 
						|
    https://github.com/GoogleCloudPlatform/kubernetes/releases/latest). 
 | 
						|
  - Ensure $TAG is the same tag as the release tag you are using for kubelet and kube-proxy.
 | 
						|
- Build your own images.
 | 
						|
  - Useful if you are using a private registry.
 | 
						|
  - The release contains files such as `./kubernetes/server/bin/kube-apiserver.tar` which
 | 
						|
    can be converted into docker images using a command like
 | 
						|
    `tar -C kube-apiserver -c . | docker import - kube-apiserver`
 | 
						|
  - *TODO*: test above command.
 | 
						|
 | 
						|
For etcd, you can:
 | 
						|
- Use images hosted on Google Container Registry (GCR), such as `gcr.io/google_containers/etcd:2.0.12`
 | 
						|
- Use images hosted on [Docker Hub](https://registry.hub.docker.com/u/coreos/etcd/) or [quay.io](https://registry.hub.docker.com/u/coreos/etcd/)
 | 
						|
- Use etcd binary included in your OS distro.
 | 
						|
- Build your own image
 | 
						|
  - You can do: `cd kubernetes/cluster/images/etcd; make`
 | 
						|
 | 
						|
We recommend that you use the etcd version which is provided in the kubernetes binary distribution.   The kubernetes binaries in the release
 | 
						|
were tested extensively with this version of etcd and not with any other version.
 | 
						|
The recommended version number can also be found as the value of `ETCD_VERSION` in `kubernetes/cluster/images/etcd/Makefile`.
 | 
						|
 | 
						|
The remainder of the document assumes that the image identifiers have been chosen and stored in corresponding env vars.  Examples (replace with latest tags and appropriate registry):
 | 
						|
  - `APISERVER_IMAGE=gcr.io/google_containers/kube-apiserver:$TAG`
 | 
						|
  - `SCHEDULER_IMAGE=gcr.io/google_containers/kube-scheduler:$TAG`
 | 
						|
  - `CNTRLMNGR_IMAGE=gcr.io/google_containers/kube-controller-manager:$TAG`
 | 
						|
  - `ETCD_IMAGE=gcr.io/google_containers/etcd:$ETCD_VERSION`
 | 
						|
 | 
						|
### Security Models
 | 
						|
 | 
						|
There are two main options for security:
 | 
						|
1. Access the apiserver using HTTP.
 | 
						|
  - Use a firewall for security.
 | 
						|
  - This is easier to setup.
 | 
						|
1. Access the apiserver using HTTPS  
 | 
						|
  - Use https with certs, and credentials for user.
 | 
						|
  - This is the recommended approach.
 | 
						|
  - Configuring certs can be tricky.
 | 
						|
 | 
						|
If following the HTTPS approach, you will need to prepare certs and credentials.
 | 
						|
 | 
						|
#### Preparing Certs
 | 
						|
You need to prepare several certs:
 | 
						|
- The master needs a cert to act as an HTTPS server.
 | 
						|
- The kubelets optionally need certs to identify themselves as clients of the master, and when
 | 
						|
  serving its own API over HTTPS.
 | 
						|
 | 
						|
Unless you plan to have a real CA generate your certs, you will need to generate a root cert and use that to sign the master, kubelet, and kubectl certs.
 | 
						|
- see function `create-certs` in `cluster/gce/util.sh`
 | 
						|
- see also `cluster/saltbase/salt/generate-cert/make-ca-cert.sh` and
 | 
						|
  `cluster/saltbase/salt/generate-cert/make-cert.sh`
 | 
						|
 | 
						|
You will end up with the following files (we will use these variables later on)
 | 
						|
- `CA_CERT`
 | 
						|
  - put in on node where apiserver runs, in e.g. `/srv/kubernetes/ca.crt`.
 | 
						|
- `MASTER_CERT`
 | 
						|
  - signed by CA_CERT
 | 
						|
  - put in on node where apiserver runs, in e.g. `/srv/kubernetes/server.crt`
 | 
						|
- `MASTER_KEY `
 | 
						|
  - put in on node where apiserver runs, in e.g. `/srv/kubernetes/server.key`
 | 
						|
- `KUBELET_CERT`
 | 
						|
  - optional
 | 
						|
- `KUBELET_KEY`
 | 
						|
  - optional
 | 
						|
 | 
						|
#### Preparing Credentials
 | 
						|
The admin user (and any users) need:
 | 
						|
  - a token or a password to identify them. 
 | 
						|
  - tokens are just long alphanumeric strings, e.g. 32 chars.  See
 | 
						|
    - `TOKEN=$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64 | tr -d "=+/" | dd bs=32 count=1 2>/dev/null)`
 | 
						|
 | 
						|
Your tokens and passwords need to be stored in a file for the apiserver
 | 
						|
to read.  This guide uses `/var/lib/kube-apiserver/known_tokens.csv`.
 | 
						|
The format for this file is described in the [authentication documentation](../authentication.md).
 | 
						|
 | 
						|
For distributing credentials to clients, the convention in Kubernetes is to put the credentials
 | 
						|
into a [kubeconfig file](../kubeconfig-file.md).
 | 
						|
 | 
						|
The kubeconfig file for the administrator can be created as follows:
 | 
						|
 - If you have already used Kubernetes with a non-custom cluster (for example, used a Getting Started
 | 
						|
   Guide), you will already have a `$HOME/.kube/config` file.
 | 
						|
 - You need to add certs, keys, and the master IP to the kubeconfig file:
 | 
						|
    - If using the firewall-only security option, set the apiserver this way:
 | 
						|
      - `kubectl config set-cluster $CLUSTER_NAME --server=http://$MASTER_IP --insecure-skip-tls-verify=true`
 | 
						|
    - Otherwise, do this to set the apiserver ip, client certs, and user credentials.
 | 
						|
      - `kubectl config set-cluster $CLUSTER_NAME --certificate-authority=$CA_CERT --embed-certs=true --server=https://$MASTER_IP`
 | 
						|
      - `kubectl config set-credentials $CLUSTER_NAME --client-certificate=$CLI_CERT --client-key=$CLI_KEY --embed-certs=true --token=$TOKEN`
 | 
						|
    - Set your cluster as the default cluster to use:
 | 
						|
      - `kubectl config set-context $CLUSTER_NAME --cluster=$CLUSTER_NAME --user=admin`
 | 
						|
      - `kubectl config use-context $CONTEXT  --cluster=$CONTEXT`
 | 
						|
 | 
						|
Next, make a kubeconfig file for the kubelets and kube-proxy.  There are a couple of options for how 
 | 
						|
many distinct files to make:
 | 
						|
  1. Use the same credential as the admin
 | 
						|
    - This is simplest to setup.
 | 
						|
  1. One token and kubeconfig file for all kubelets, one for all kube-proxy, one for admin.
 | 
						|
    - This mirrors what is done on GCE today
 | 
						|
  1. Different credentials for every kubelet, etc.
 | 
						|
    - We are working on this but all the pieces are not ready yet.
 | 
						|
 | 
						|
You can make the files by copying the `$HOME/.kube/config`, by following the code
 | 
						|
in `cluster/gce/configure-vm.sh` or by using the following template:
 | 
						|
```
 | 
						|
apiVersion: v1
 | 
						|
kind: Config
 | 
						|
users:
 | 
						|
- name: kubelet
 | 
						|
  user:
 | 
						|
    token: ${KUBELET_TOKEN}
 | 
						|
clusters:
 | 
						|
- name: local
 | 
						|
  cluster:
 | 
						|
    certificate-authority-data: ${CA_CERT_BASE64_ENCODED}
 | 
						|
contexts:
 | 
						|
- context:
 | 
						|
    cluster: local
 | 
						|
    user: kubelet
 | 
						|
  name: service-account-context
 | 
						|
current-context: service-account-context
 | 
						|
```
 | 
						|
Put the kubeconfig(s) on every node.  The examples later in this
 | 
						|
guide assume that there are kubeconfigs in `/var/lib/kube-proxy/kubeconfig` and
 | 
						|
`/var/lib/kubelet/kubeconfig`.
 | 
						|
 | 
						|
## Configuring and Installing Base Software on Nodes
 | 
						|
 | 
						|
This section discusses how to configure machines to be kubernetes nodes. 
 | 
						|
 | 
						|
You should run three daemons on every node:
 | 
						|
  - docker or rkt
 | 
						|
  - kubelet
 | 
						|
  - kube-proxy
 | 
						|
 | 
						|
You will also need to do assorted other configuration on top of a
 | 
						|
base OS install.
 | 
						|
 | 
						|
Tip: One possible starting point is to setup a cluster using an existing Getting
 | 
						|
Started Guide.   After getting a cluster running, you can then copy the init.d scripts or systemd unit files from that
 | 
						|
cluster, and then modify them for use on your custom cluster.
 | 
						|
 | 
						|
### Docker
 | 
						|
The minimum required Docker version will vary as the kubelet version changes.  The newest stable release is a good choice.  Kubelet will log a warning and refuse to start pods if the version is too old, so pick a version and try it.
 | 
						|
 | 
						|
If you previously had Docker installed on a node without setting Kubernetes-specific
 | 
						|
options, you may have a Docker-created bridge and iptables rules.  You may want to remove these
 | 
						|
as follows before proceeding to configure Docker for Kubernetes.
 | 
						|
```
 | 
						|
iptables -t nat -F 
 | 
						|
ifconfig docker0 down
 | 
						|
brctl delbr docker0
 | 
						|
```
 | 
						|
 | 
						|
The way you configure docker will depend in whether you have chosen the routable-vip or overlay-network approaches for your network.
 | 
						|
Some docker options will want to think about:
 | 
						|
  - create your own bridge for the per-node CIDR ranges, and set `--bridge=cbr0` and `--bip=false`.  Or let docker do it with `--bip=true`.
 | 
						|
  - `--iptables=false` so docker will not manipulate iptables for host-ports (too coarse on older docker versions, may be fixed in newer versions)
 | 
						|
so that kube-proxy can manage iptables instead of docker.
 | 
						|
  - `--ip-masq=false`
 | 
						|
    - if you have setup PodIPs to be routable, then you want this false, otherwise, docker will
 | 
						|
      rewrite the PodIP source-address to a NodeIP.
 | 
						|
    - some environments (e.g. GCE) still need you to masquerade out-bound traffic when it leaves the cloud environment. This is very environment specific.
 | 
						|
    - if you are using an overlay network, consult those instructions.  
 | 
						|
  - `--bip=`
 | 
						|
    - should be the CIDR range for pods for that specific node.
 | 
						|
  - `--mtu=`
 | 
						|
    - may be required when using Flannel, because of the extra packet size due to udp encapsulation
 | 
						|
  - `--insecure-registry $CLUSTER_SUBNET` 
 | 
						|
    - to connect to a private registry, if you set one up, without using SSL.
 | 
						|
 | 
						|
You may want to increase the number of open files for docker:
 | 
						|
   - `DOCKER_NOFILE=1000000`
 | 
						|
 | 
						|
Where this config goes depends on your node OS.  For example, GCE's Debian-based distro uses `/etc/default/docker`.
 | 
						|
 | 
						|
Ensure docker is working correctly on your system before proceeding with the rest of the
 | 
						|
installation, by following examples given in the Docker documentation.
 | 
						|
 | 
						|
### rkt
 | 
						|
 | 
						|
[rkt](https://github.com/coreos/rkt) is an alternative to Docker.  You only need to install one of Docker or rkt.
 | 
						|
 | 
						|
*TODO*: how to install and configure rkt.
 | 
						|
 | 
						|
### kubelet
 | 
						|
 | 
						|
All nodes should run kubelet.  See [Selecting Binaries](#selecting-binaries).
 | 
						|
 | 
						|
Arguments to consider:
 | 
						|
  - If following the HTTPS security approach:
 | 
						|
    - `--api-servers=https://$MASTER_IP`
 | 
						|
    - `--kubeconfig=/var/lib/kubelet/kubeconfig`
 | 
						|
  - Otherwise, if taking the firewall-based security approach
 | 
						|
    - `--api-servers=http://$MASTER_IP`
 | 
						|
  - `--config=/etc/kubernetes/manifests` -%}
 | 
						|
  - `--cluster-dns=` to the address of the DNS server you will setup (see [Starting Addons](#starting-addons).)
 | 
						|
  - `--cluster-domain=` to the dns domain prefix to use for cluster DNS addresses.
 | 
						|
  - `--docker-root=`
 | 
						|
  - `--root-dir=`
 | 
						|
  - `--configure-cbr0=` (described above)
 | 
						|
  - `--register-node` (described in [Node](../node.md) documentation.
 | 
						|
 | 
						|
### kube-proxy
 | 
						|
 | 
						|
All nodes should run kube-proxy.  (Running kube-proxy on a "master" node is not
 | 
						|
strictly required, but being consistent is easier.)   Obtain a binary as described for
 | 
						|
kubelet. 
 | 
						|
 | 
						|
Arguments to consider:
 | 
						|
  - If following the HTTPS security approach:
 | 
						|
    - `--api-servers=https://$MASTER_IP`
 | 
						|
    - `--kubeconfig=/var/lib/kube-proxy/kubeconfig`
 | 
						|
  - Otherwise, if taking the firewall-based security approach
 | 
						|
    - `--api-servers=http://$MASTER_IP`
 | 
						|
 | 
						|
### Networking
 | 
						|
Each node needs to be allocated its own CIDR range for pod networking.
 | 
						|
Call this `NODE_X_POD_CIDR`.
 | 
						|
 | 
						|
A bridge called `cbr0` needs to be created on each node.  The bridge is explained
 | 
						|
further in the [networking documentation](../networking.md).  The bridge itself
 | 
						|
needs an address from `$NODE_X_POD_CIDR` - by convention the first IP.  Call
 | 
						|
this `NODE_X_BRIDGE_ADDR`.  For example, if `NODE_X_POD_CIDR` is `10.0.0.0/16`,
 | 
						|
then `NODE_X_BRIDGE_ADDR` is `10.0.0.1/16`.  NOTE: this retains the `/16` suffix
 | 
						|
because of how this is used later.
 | 
						|
 | 
						|
- Recommended, automatic approach:
 | 
						|
  1. Set `--configure-cbr0=true` option in kubelet init script and restart kubelet service.  Kubelet will configure cbr0 automatically.
 | 
						|
     It will wait to do this until the node controller has set Node.Spec.PodCIDR.  Since you have not setup apiserver and node controller
 | 
						|
     yet, the bridge will not be setup immediately.
 | 
						|
- Alternate, manual approach:
 | 
						|
  1. Set `--configure-cbr0=false` on kubelet and restart.
 | 
						|
  1. Create a bridge
 | 
						|
  - e.g. `brctl addbr cbr0`.
 | 
						|
  1. Set appropriate MTU
 | 
						|
  - `ip link set dev cbr0 mtu 1460` (NOTE: the actual value of MTU will depend on your network environment)
 | 
						|
  1. Add the clusters network to the bridge (docker will go on other side of bridge).
 | 
						|
  - e.g. `ip addr add $NODE_X_BRIDGE_ADDR dev eth0`
 | 
						|
  1. Turn it on
 | 
						|
  - e.g. `ip link set dev cbr0 up`
 | 
						|
 | 
						|
If you have turned off Docker's IP masquerading to allow pods to talk to each
 | 
						|
other, then you may need to do masquerading just for destination IPs outside
 | 
						|
the cluster network.  For example:
 | 
						|
```iptables -w -t nat -A POSTROUTING -o eth0 -j MASQUERADE \! -d ${CLUSTER_SUBNET}```
 | 
						|
This will rewrite the source address from
 | 
						|
the PodIP to the Node IP for traffic bound outside the cluster, and kernel
 | 
						|
[connection tracking](http://www.iptables.info/en/connection-state.html)
 | 
						|
will ensure that responses destined to the node still reach
 | 
						|
the pod.
 | 
						|
 | 
						|
NOTE: This is environment specific.  Some environments will not need
 | 
						|
any masquerading at all.  Others, such as GCE, will not allow pod IPs to send
 | 
						|
traffic to the internet, but have no problem with them inside your GCE Project.
 | 
						|
 | 
						|
### Other 
 | 
						|
- Enable auto-upgrades for your OS package manager, if desired.
 | 
						|
- Configure log rotation for all node components (e.g. using [logrotate](http://linux.die.net/man/8/logrotate)).
 | 
						|
- Setup liveness-monitoring (e.g. using [monit](http://linux.die.net/man/1/monit)).
 | 
						|
- Setup volume plugin support (optional)
 | 
						|
  - Install any client binaries for optional volume types, such as `glusterfs-client` for GlusterFS
 | 
						|
    volumes.
 | 
						|
 | 
						|
### Using Configuration Management
 | 
						|
The previous steps all involved "conventional" system administration techniques for setting up
 | 
						|
machines.  You may want to use a Configuration Management system to automate the node configuration
 | 
						|
process.  There are examples of [Saltstack](../salt.md), Ansible, Juju, and CoreOS Cloud Config in the
 | 
						|
various Getting Started Guides.
 | 
						|
 | 
						|
## Bootstrapping the Cluster
 | 
						|
 | 
						|
While the basic node services (kubelet, kube-proxy, docker) are typically started and managed using
 | 
						|
traditional system administration/automation approaches, the remaining *master* components of Kubernetes are
 | 
						|
all configured and managed *by Kubernetes*:
 | 
						|
  - their options are specified in a Pod spec (yaml or json) rather than an /etc/init.d file or
 | 
						|
    systemd unit.
 | 
						|
  - they are kept running by Kubernetes rather than by init.
 | 
						|
 | 
						|
### etcd
 | 
						|
You will need to run one or more instances of etcd.  
 | 
						|
  - Recommended approach: run one etcd instance, with its log written to a directory backed
 | 
						|
    by durable storage (RAID, GCE PD)
 | 
						|
  - Alternative: run 3 or 5 etcd instances.
 | 
						|
    - Log can be written to non-durable storage because storage is replicated. 
 | 
						|
    - run a single apiserver which connects to one of the etc nodes.
 | 
						|
 See [Availability](../availability.md) for more discussion on factors affecting cluster
 | 
						|
availability.
 | 
						|
 | 
						|
To run an etcd instance:
 | 
						|
1. copy `cluster/saltbase/salt/etcd/etcd.manifest`
 | 
						|
1. make any modifications needed
 | 
						|
1. start the pod by putting it into the kubelet manifest directory
 | 
						|
 | 
						|
### Apiserver
 | 
						|
 | 
						|
To run the apiserver:
 | 
						|
1. select the correct flags for your cluster
 | 
						|
1. write a pod spec for the apiserver using the provided template
 | 
						|
1. start the pod by putting it into the kubelet manifest directory
 | 
						|
 | 
						|
Here are some apiserver flags you may need to set:
 | 
						|
  - `--cloud-provider=`
 | 
						|
  - `--cloud-config=` if cloud provider requires a config file (GCE, AWS). If so, need to put config file into apiserver image or mount through hostPath.
 | 
						|
  - `--address=${MASTER_IP}`.  
 | 
						|
   - or `--bind-address=127.0.0.1` and `--address=127.0.0.1` if you want to run a proxy on the master node.
 | 
						|
  - `--cluster-name=$CLUSTER_NAME`
 | 
						|
  - `--service-cluster-ip-range=$SERVICE_CLUSTER_IP_RANGE`
 | 
						|
  - `--etcd-servers=http://127.0.0.1:4001`
 | 
						|
  - `--tls-cert-file=/srv/kubernetes/server.cert` -%}
 | 
						|
  - `--tls-private-key-file=/srv/kubernetes/server.key` -%}
 | 
						|
  - `--admission-control=$RECOMMENDED_LIST`
 | 
						|
    - See [admission controllers](../admission_controllers.md) for recommended arguments.
 | 
						|
  - `--allow-privileged=true`, only if you trust your cluster user to run pods as root.
 | 
						|
 
 | 
						|
If you are following the firewall-only security approach, then use these arguments:
 | 
						|
  - `--token-auth-file=/dev/null`
 | 
						|
  - `--insecure-bind-address=$MASTER_IP`
 | 
						|
  - `--advertise-address=$MASTER_IP`
 | 
						|
 | 
						|
If you are using the HTTPS approach, then set:
 | 
						|
  - `--client-ca-file=/srv/kubernetes/ca.crt`
 | 
						|
  - `--token-auth-file=/srv/kubernetes/known_tokens.csv`
 | 
						|
  - `--basic-auth-file=/srv/kubernetes/basic_auth.csv`
 | 
						|
 | 
						|
*TODO* document proxy-ssh setup.
 | 
						|
 | 
						|
#### Apiserver pod template
 | 
						|
 | 
						|
```json
 | 
						|
{
 | 
						|
  "kind": "Pod",
 | 
						|
  "apiVersion": "v1",
 | 
						|
  "metadata": {
 | 
						|
    "name": "kube-apiserver"
 | 
						|
  },
 | 
						|
  "spec": {
 | 
						|
    "hostNetwork": true,
 | 
						|
    "containers": [
 | 
						|
      {
 | 
						|
        "name": "kube-apiserver",
 | 
						|
        "image": "${APISERVER_IMAGE}",
 | 
						|
        "command": [
 | 
						|
          "/bin/sh",
 | 
						|
          "-c",
 | 
						|
          "/usr/local/bin/kube-apiserver $ARGS"
 | 
						|
        ],
 | 
						|
        "ports": [
 | 
						|
          {
 | 
						|
            "name": "https",
 | 
						|
            "hostPort": 443,
 | 
						|
            "containerPort": 443
 | 
						|
          },
 | 
						|
          {
 | 
						|
            "name": "local",
 | 
						|
            "hostPort": 8080,
 | 
						|
            "containerPort": 8080
 | 
						|
          }
 | 
						|
        ],
 | 
						|
        "volumeMounts": [
 | 
						|
          {
 | 
						|
            "name": "srvkube",
 | 
						|
            "mountPath": "/srv/kubernetes",
 | 
						|
            "readOnly": true
 | 
						|
          },
 | 
						|
          {
 | 
						|
            "name": "etcssl",
 | 
						|
            "mountPath": "/etc/ssl",
 | 
						|
            "readOnly": true
 | 
						|
          }
 | 
						|
        ],
 | 
						|
        "livenessProbe": {
 | 
						|
          "httpGet": {
 | 
						|
            "path": "/healthz",
 | 
						|
            "port": 8080
 | 
						|
          },
 | 
						|
          "initialDelaySeconds": 15,
 | 
						|
          "timeoutSeconds": 15
 | 
						|
        }
 | 
						|
      }
 | 
						|
    ],
 | 
						|
    "volumes": [
 | 
						|
      {
 | 
						|
        "name": "srvkube",
 | 
						|
        "hostPath": {
 | 
						|
          "path": "/srv/kubernetes"
 | 
						|
        }
 | 
						|
      },
 | 
						|
      {
 | 
						|
        "name": "etcssl",
 | 
						|
        "hostPath": {
 | 
						|
          "path": "/etc/ssl"
 | 
						|
        }
 | 
						|
      }
 | 
						|
    ]
 | 
						|
  }
 | 
						|
}
 | 
						|
```
 | 
						|
 | 
						|
The `/etc/ssl` mount allows the apiserver to find the SSL root certs so it can
 | 
						|
authenticate external services, such as a cloud provider.
 | 
						|
 | 
						|
The `/srv/kubernetes` mount allows the apiserver to read certs and credentials stored on the
 | 
						|
node disk.
 | 
						|
 | 
						|
Optionally, you may want to mount `/var/log` as well and redirect output there.
 | 
						|
 | 
						|
#### Starting Apiserver
 | 
						|
Place the completed pod template into the kubelet config dir
 | 
						|
(whatever `--config=` argument of kubelet is set to, typically
 | 
						|
`/etc/kubernetes/manifests`).
 | 
						|
 | 
						|
Next, verify that kubelet has started a container for the apiserver:
 | 
						|
```
 | 
						|
$ sudo docker ps | grep apiserver:
 | 
						|
5783290746d5        gcr.io/google_containers/kube-apiserver:e36bf367342b5a80d7467fd7611ad873            "/bin/sh -c '/usr/lo'"    10 seconds ago      Up 9 seconds                              k8s_kube-apiserver.feb145e7_kube-apiserver-kubernetes-master_default_eaebc600cf80dae59902b44225f2fc0a_225a4695   ```
 | 
						|
```
 | 
						|
 | 
						|
Then try to connect to the apiserver:
 | 
						|
```
 | 
						|
$ echo $(curl -s http://localhost:8080/healthz)
 | 
						|
ok
 | 
						|
$ curl -s http://localhost:8080/api
 | 
						|
{
 | 
						|
  "versions": [
 | 
						|
    "v1beta3",
 | 
						|
    "v1"
 | 
						|
  ]
 | 
						|
}
 | 
						|
```
 | 
						|
 | 
						|
If you have selected the `--register-node=true` option for kubelets, they will now being self-registering with the apiserver.
 | 
						|
You should soon be able to see all your nodes by running the `kubect get nodes` command.
 | 
						|
Otherwise, you will need to manually create node objects.
 | 
						|
 | 
						|
### Scheduler
 | 
						|
 | 
						|
Complete this template for the scheduler pod:
 | 
						|
```json
 | 
						|
{
 | 
						|
  "kind": "Pod",
 | 
						|
  "apiVersion": "v1",
 | 
						|
  "metadata": {
 | 
						|
    "name": "kube-scheduler"
 | 
						|
  },
 | 
						|
  "spec": {
 | 
						|
    "hostNetwork": true,
 | 
						|
    "containers": [
 | 
						|
      {
 | 
						|
        "name": "kube-scheduler",
 | 
						|
        "image": "$SCHEDULER_IMAGE",
 | 
						|
        "command": [
 | 
						|
          "/bin/sh",
 | 
						|
          "-c",
 | 
						|
          "/usr/local/bin/kube-scheduler --master=127.0.0.1:8080"
 | 
						|
        ],
 | 
						|
        "livenessProbe": {
 | 
						|
          "httpGet": {
 | 
						|
            "path": "/healthz",
 | 
						|
            "port": 10251
 | 
						|
          },
 | 
						|
          "initialDelaySeconds": 15,
 | 
						|
          "timeoutSeconds": 15
 | 
						|
        }
 | 
						|
      }
 | 
						|
    ]
 | 
						|
  }
 | 
						|
}
 | 
						|
```
 | 
						|
Optionally, you may want to mount `/var/log` as well and redirect output there.
 | 
						|
 | 
						|
Start as described for apiserver.
 | 
						|
 | 
						|
### Controller Manager
 | 
						|
To run the controller manager:
 | 
						|
  - select the correct flags for your cluster
 | 
						|
  - write a pod spec for the controller manager using the provided template
 | 
						|
  - start the controller manager pod
 | 
						|
 | 
						|
Flags to consider using with controller manager.
 | 
						|
 - `--cluster-name=$CLUSTER_NAME`
 | 
						|
 - `--cluster-cidr=`
 | 
						|
   - *TODO*: explain this flag.
 | 
						|
 - `--allocate-node-cidrs=`
 | 
						|
   - *TODO*: explain when you want controller to do this and when you wanna do it another way.
 | 
						|
 - `--cloud-provider=` and `--cloud-config` as described in apiserver section.
 | 
						|
 - `--service-account-private-key-file=/srv/kubernetes/server.key`, used by [service account](../service_accounts.md) feature.  
 | 
						|
 - `--master=127.0.0.1:8080`
 | 
						|
 | 
						|
Template for controller manager pod:
 | 
						|
```json
 | 
						|
{
 | 
						|
  "kind": "Pod",
 | 
						|
  "apiVersion": "v1",
 | 
						|
  "metadata": {
 | 
						|
    "name": "kube-controller-manager"
 | 
						|
  },
 | 
						|
  "spec": {
 | 
						|
    "hostNetwork": true,
 | 
						|
    "containers": [
 | 
						|
      {
 | 
						|
        "name": "kube-controller-manager",
 | 
						|
        "image": "$CNTRLMNGR_IMAGE",
 | 
						|
        "command": [
 | 
						|
          "/bin/sh",
 | 
						|
          "-c",
 | 
						|
          "/usr/local/bin/kube-controller-manager $ARGS"
 | 
						|
        ],
 | 
						|
        "volumeMounts": [
 | 
						|
          {
 | 
						|
            "name": "srvkube",
 | 
						|
            "mountPath": "/srv/kubernetes",
 | 
						|
            "readOnly": true
 | 
						|
          },
 | 
						|
          {
 | 
						|
            "name": "etcssl",
 | 
						|
            "mountPath": "/etc/ssl",
 | 
						|
            "readOnly": true
 | 
						|
          }
 | 
						|
        ],
 | 
						|
        "livenessProbe": {
 | 
						|
          "httpGet": {
 | 
						|
            "path": "/healthz",
 | 
						|
            "port": 10252
 | 
						|
          },
 | 
						|
          "initialDelaySeconds": 15,
 | 
						|
          "timeoutSeconds": 15
 | 
						|
        }
 | 
						|
      }
 | 
						|
    ],
 | 
						|
    "volumes": [
 | 
						|
      {
 | 
						|
        "name": "srvkube",
 | 
						|
        "hostPath": {
 | 
						|
          "path": "/srv/kubernetes"
 | 
						|
        }
 | 
						|
      },
 | 
						|
      {
 | 
						|
        "name": "etcssl",
 | 
						|
        "hostPath": {
 | 
						|
          "path": "/etc/ssl"
 | 
						|
        }
 | 
						|
      }
 | 
						|
    ]
 | 
						|
  }
 | 
						|
}
 | 
						|
```
 | 
						|
 | 
						|
 | 
						|
### Logging
 | 
						|
 | 
						|
**TODO** talk about starting Logging.
 | 
						|
 | 
						|
### Monitoring
 | 
						|
 | 
						|
**TODO** talk about starting Logging.
 | 
						|
 | 
						|
### DNS
 | 
						|
 | 
						|
**TODO** talk about starting DNS.
 | 
						|
 | 
						|
## Troubleshooting
 | 
						|
 | 
						|
### Running validate-cluster
 | 
						|
 | 
						|
**TODO** explain how to use `cluster/validate-cluster.sh`
 | 
						|
 | 
						|
### Inspect pods and services
 | 
						|
 | 
						|
Try to run through the "Inspect your cluster" section in one of the other Getting Started Guides, such as [GCE](gce.md#inspect-your-cluster).
 | 
						|
You should see some services.  You should also see "mirror pods" for the apiserver, scheduler and controller-manager, plus any add-ons you started.
 | 
						|
 | 
						|
### Try Examples
 | 
						|
 | 
						|
At this point you should be able to run through one of the basic examples, such as the [nginx example](../../examples/simple-nginx.md).
 | 
						|
 | 
						|
### Running the Conformance Test
 | 
						|
 | 
						|
You may want to try to run the [Conformance test](../../hack/conformance-test.sh).  Any failures may give a hint as to areas that need more attention.
 | 
						|
 | 
						|
### Networking
 | 
						|
 | 
						|
The nodes must be able to connect to each other using their private IP. Verify this by
 | 
						|
pinging or SSH-ing from one node to another.
 | 
						|
 | 
						|
### Getting Help
 | 
						|
If you run into trouble, please see the section on [troubleshooting](gce.md#troubleshooting), post to the
 | 
						|
[google-containers group](https://groups.google.com/forum/#!forum/google-containers), or come ask questions on IRC at #google-containers on freenode.
 | 
						|
 | 
						|
 | 
						|
<!-- BEGIN MUNGE: GENERATED_ANALYTICS -->
 | 
						|
[]()
 | 
						|
<!-- END MUNGE: GENERATED_ANALYTICS -->
 |