Remove the old setup from scratch documentation (#13146)
because it was woefully outdated.
This commit is contained in:
committed by
Kubernetes Prow Robot
parent
a15d6ebed9
commit
3f8bc96336
@@ -46,8 +46,14 @@ a Kubernetes cluster from scratch.
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## Local-machine Solutions
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### Community Supported Tools
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* [Minikube](/docs/setup/minikube/) is a method for creating a local, single-node Kubernetes cluster for development and testing. Setup is completely automated and doesn't require a cloud provider account.
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* [Kubeadm-dind](https://github.com/kubernetes-sigs/kubeadm-dind-cluster) is a multi-node (while minikube is single-node) Kubernetes cluster which only requires a docker daemon. It uses docker-in-docker technique to spawn the Kubernetes cluster.
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### Ecosystem Tools
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* [Docker Desktop](https://www.docker.com/products/docker-desktop) is an
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easy-to-install application for your Mac or Windows environment that enables you to
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start coding and deploying in containers in minutes on a single-node Kubernetes
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@@ -61,8 +67,6 @@ cluster.
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* [IBM Cloud Private-CE (Community Edition) on Linux Containers](https://github.com/HSBawa/icp-ce-on-linux-containers) is a Terraform/Packer/BASH based Infrastructure as Code (IaC) scripts to create a seven node (1 Boot, 1 Master, 1 Management, 1 Proxy and 3 Workers) LXD cluster on Linux Host.
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* [Kubeadm-dind](https://github.com/kubernetes-sigs/kubeadm-dind-cluster) is a multi-node (while minikube is single-node) Kubernetes cluster which only requires a docker daemon. It uses docker-in-docker technique to spawn the Kubernetes cluster.
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* [Ubuntu on LXD](/docs/getting-started-guides/ubuntu/local/) supports a nine-instance deployment on localhost.
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## Hosted Solutions
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@@ -170,10 +174,7 @@ few commands.
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Kubernetes can run on a wide range of Cloud providers and bare-metal environments, and with many
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base operating systems.
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If you can find a guide below that matches your needs, use it. It may be a little out of date, but
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it will be easier than starting from scratch. If you do want to start from scratch, either because you
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have special requirements, or just because you want to understand what is underneath a Kubernetes
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cluster, try the [Getting Started from Scratch](/docs/setup/scratch/) guide.
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If you can find a guide below that matches your needs, use it.
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### Universal
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@@ -272,7 +273,6 @@ AWS | Saltstack | Debian | AWS | [docs](/docs/setup/
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AWS | kops | Debian | AWS | [docs](https://github.com/kubernetes/kops/) | Community ([@justinsb](https://github.com/justinsb))
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Bare-metal | custom | Ubuntu | flannel | [docs](/docs/getting-started-guides/ubuntu/) | Community ([@resouer](https://github.com/resouer), [@WIZARD-CXY](https://github.com/WIZARD-CXY))
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oVirt | | | | [docs](/docs/setup/on-premises-vm/ovirt/) | Community ([@simon3z](https://github.com/simon3z))
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any | any | any | any | [docs](/docs/setup/scratch/) | Community ([@erictune](https://github.com/erictune))
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any | any | any | any | [docs](http://docs.projectcalico.org/v2.2/getting-started/kubernetes/installation/) | Commercial and Community
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any | RKE | multi-support | flannel or canal | [docs](https://rancher.com/docs/rancher/v2.x/en/quick-start-guide/) | [Commercial](https://rancher.com/what-is-rancher/overview/) and [Community](https://github.com/rancher/rancher)
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any | [Gardener Cluster-Operator](https://kubernetes.io/blog/2018/05/17/gardener/) | multi-support | multi-support | [docs](https://gardener.cloud) | [Project/Community](https://github.com/gardener) and [Commercial]( https://cloudplatform.sap.com/)
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@@ -1,876 +0,0 @@
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---
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reviewers:
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- erictune
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- lavalamp
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- thockin
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title: Creating a Custom Cluster from Scratch
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---
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This guide is for people who want to craft a custom Kubernetes cluster. If you
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can find an existing Getting Started Guide that meets your needs on [this
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list](/docs/setup/), then we recommend using it, as you will be able to benefit
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from the experience of others. However, if you have specific IaaS, networking,
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configuration management, or operating system requirements not met by any of
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those guides, then this guide will provide an outline of the steps you need to
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take. Note that it requires considerably more effort than using one of the
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pre-defined guides.
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This guide is also useful for those wanting to understand at a high level some of the
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steps that existing cluster setup scripts are making.
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{{< toc >}}
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## Designing and Preparing
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### Learning
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1. You should be familiar with using Kubernetes already. We suggest you set
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up a temporary cluster by following one of the other Getting Started Guides.
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This will help you become familiar with the CLI ([kubectl](/docs/user-guide/kubectl/)) and concepts ([pods](/docs/user-guide/pods/), [services](/docs/concepts/services-networking/service/), etc.) first.
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1. You should have `kubectl` installed on your desktop. This will happen as a side
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effect of completing one of the other Getting Started Guides. If not, follow the instructions
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[here](/docs/tasks/kubectl/install/).
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### Cloud Provider
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Kubernetes has the concept of a Cloud Provider, which is a module which provides
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an interface for managing TCP Load Balancers, Nodes (Instances) and Networking Routes.
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The interface is defined in `pkg/cloudprovider/cloud.go`. It is possible to
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create a custom cluster without implementing a cloud provider (for example if using
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bare-metal), and not all parts of the interface need to be implemented, depending
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on how flags are set on various components.
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### Nodes
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- You can use virtual or physical machines.
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- While you can build a cluster with 1 machine, in order to run all the examples and tests you
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need at least 4 nodes.
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- Many Getting-started-guides make a distinction between the master node and regular nodes. This
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is not strictly necessary.
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- Nodes will need to run some version of Linux with the x86_64 architecture. It may be possible
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to run on other OSes and Architectures, but this guide does not try to assist with that.
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- Apiserver and etcd together are fine on a machine with 1 core and 1GB RAM for clusters with 10s of nodes.
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Larger or more active clusters may benefit from more cores.
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- Other nodes can have any reasonable amount of memory and any number of cores. They need not
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have identical configurations.
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### Network
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#### Network Connectivity
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Kubernetes has a distinctive [networking model](/docs/concepts/cluster-administration/networking/).
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Kubernetes allocates an IP address to each pod. When creating a cluster, you
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need to allocate a block of IPs for Kubernetes to use as Pod IPs. The simplest
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approach is to allocate a different block of IPs to each node in the cluster as
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the node is added. A process in one pod should be able to communicate with
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another pod using the IP of the second pod. This connectivity can be
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accomplished in two ways:
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- **Using an overlay network**
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- An overlay network obscures the underlying network architecture from the
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pod network through traffic encapsulation (for example vxlan).
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- Encapsulation reduces performance, though exactly how much depends on your solution.
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- **Without an overlay network**
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- Configure the underlying network fabric (switches, routers, etc.) to be aware of pod IP addresses.
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- This does not require the encapsulation provided by an overlay, and so can achieve
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better performance.
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Which method you choose depends on your environment and requirements. There are various ways
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to implement one of the above options:
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- **Use a network plugin which is called by Kubernetes**
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- Kubernetes supports the [CNI](https://github.com/containernetworking/cni) network plugin interface.
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- There are a number of solutions which provide plugins for Kubernetes (listed alphabetically):
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- [Calico](http://docs.projectcalico.org/)
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- [Flannel](https://github.com/coreos/flannel)
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- [Open vSwitch (OVS)](http://openvswitch.org/)
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- [Romana](http://romana.io/)
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- [Weave](http://weave.works/)
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- [More found here](/docs/admin/networking#how-to-achieve-this/)
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- You can also write your own.
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- **Compile support directly into Kubernetes**
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- This can be done by implementing the "Routes" interface of a Cloud Provider module.
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- The Google Compute Engine ([GCE](/docs/setup/turnkey/gce/)) and [AWS](/docs/setup/turnkey/aws/) guides use this approach.
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- **Configure the network external to Kubernetes**
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- This can be done by manually running commands, or through a set of externally maintained scripts.
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- You have to implement this yourself, but it can give you an extra degree of flexibility.
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You will need to select an address range for the Pod IPs.
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- Various approaches:
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- GCE: each project has its own `10.0.0.0/8`. Carve off a `/16` for each
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Kubernetes cluster from that space, which leaves room for several clusters.
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Each node gets a further subdivision of this space.
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- AWS: use one VPC for whole organization, carve off a chunk for each
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cluster, or use different VPC for different clusters.
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- Allocate one CIDR subnet for each node's PodIPs, or a single large CIDR
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from which smaller CIDRs are automatically allocated to each node.
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- You need max-pods-per-node * max-number-of-nodes IPs in total. A `/24` per
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node supports 254 pods per machine and is a common choice. If IPs are
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scarce, a `/26` (62 pods per machine) or even a `/27` (30 pods) may be sufficient.
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- For example, use `10.10.0.0/16` as the range for the cluster, with up to 256 nodes
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using `10.10.0.0/24` through `10.10.255.0/24`, respectively.
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- Need to make these routable or connect with overlay.
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Kubernetes also allocates an IP to each [service](/docs/concepts/services-networking/service/). However,
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service IPs do not necessarily need to be routable. The kube-proxy takes care
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of translating Service IPs to Pod IPs before traffic leaves the node. You do
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need to allocate a block of IPs for services. Call this
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`SERVICE_CLUSTER_IP_RANGE`. For example, you could set
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`SERVICE_CLUSTER_IP_RANGE="10.0.0.0/16"`, allowing 65534 distinct services to
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be active at once. Note that you can grow the end of this range, but you
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cannot move it without disrupting the services and pods that already use it.
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Also, you need to pick a static IP for master node.
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- Call this `MASTER_IP`.
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- Open any firewalls to allow access to the apiserver ports 80 and/or 443.
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- Enable ipv4 forwarding sysctl, `net.ipv4.ip_forward = 1`
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#### Network Policy
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Kubernetes enables the definition of fine-grained network policy between Pods using the [NetworkPolicy](/docs/concepts/services-networking/network-policies/) resource.
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Not all networking providers support the Kubernetes NetworkPolicy API, see [Using Network Policy](/docs/tasks/configure-pod-container/declare-network-policy/) for more information.
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### Cluster Naming
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You should pick a name for your cluster. Pick a short name for each cluster
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which is unique from future cluster names. This will be used in several ways:
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- by kubectl to distinguish between various clusters you have access to. You will probably want a
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second one sometime later, such as for testing new Kubernetes releases, running in a different
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region of the world, etc.
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- Kubernetes clusters can create cloud provider resources (for example, AWS ELBs) and different clusters
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need to distinguish which resources each created. Call this `CLUSTER_NAME`.
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### Software Binaries
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You will need binaries for:
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- etcd
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- A container runner, one of:
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- docker
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- rkt
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- Kubernetes
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- kubelet
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- kube-proxy
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- kube-apiserver
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- kube-controller-manager
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- kube-scheduler
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#### Downloading and Extracting Kubernetes Binaries
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A Kubernetes binary release includes all the Kubernetes binaries as well as the supported release of etcd.
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You can use a Kubernetes binary release (recommended) or build your Kubernetes binaries following the instructions in the
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[Developer Documentation](https://git.k8s.io/community/contributors/devel/). Only using a binary release is covered in this guide.
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Download the [latest binary release](https://github.com/kubernetes/kubernetes/releases/latest) and unzip it.
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Server binary tarballs are no longer included in the Kubernetes final tarball, so you will need to locate and run
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`./kubernetes/cluster/get-kube-binaries.sh` to download and extract the client and server binaries.
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Then locate `./kubernetes/server/bin`, which contains all the necessary binaries.
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#### Selecting Images
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You will run docker, kubelet, and kube-proxy outside of a container, the same way you would run any system daemon, so
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you just need the bare binaries. For etcd, kube-apiserver, kube-controller-manager, and kube-scheduler,
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we recommend that you run these as containers, so you need an image to be built.
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You have several choices for Kubernetes images:
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- Use images hosted on Google Container Registry (GCR):
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- For example `k8s.gcr.io/hyperkube:$TAG`, where `TAG` is the latest
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release tag, which can be found on the [latest releases page](https://github.com/kubernetes/kubernetes/releases/latest).
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- Ensure $TAG is the same tag as the release tag you are using for kubelet and kube-proxy.
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- The [hyperkube](https://releases.k8s.io/{{< param "githubbranch" >}}/cmd/hyperkube) binary is an all in one binary
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- `hyperkube kubelet ...` runs the kubelet, `hyperkube apiserver ...` runs an apiserver, etc.
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- Build your own images.
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- Useful if you are using a private registry.
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- The release contains files such as `./kubernetes/server/bin/kube-apiserver.tar` which
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can be converted into docker images using a command like
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`docker load -i kube-apiserver.tar`
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- You can verify if the image is loaded successfully with the right repository and tag using
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command like `docker images`
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We recommend that you use the etcd version which is provided in the Kubernetes binary distribution. The Kubernetes binaries in the release
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were tested extensively with this version of etcd and not with any other version.
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The recommended version number can also be found as the value of `TAG` in `kubernetes/cluster/images/etcd/Makefile`.
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For the minimum recommended version of etcd, refer to
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[Configuring and Updating etcd](/docs/tasks/administer-cluster/configure-upgrade-etcd/)
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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):
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- `HYPERKUBE_IMAGE=k8s.gcr.io/hyperkube:$TAG`
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- `ETCD_IMAGE=k8s.gcr.io/etcd:$ETCD_VERSION`
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### Security Models
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There are two main options for security:
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- Access the apiserver using HTTP.
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- Use a firewall for security.
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- This is easier to setup.
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- Access the apiserver using HTTPS
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- Use https with certs, and credentials for user.
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- This is the recommended approach.
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- Configuring certs can be tricky.
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If following the HTTPS approach, you will need to prepare certs and credentials.
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#### Preparing Certs
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You need to prepare several certs:
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- The master needs a cert to act as an HTTPS server.
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- The kubelets optionally need certs to identify themselves as clients of the master, and when
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serving its own API over HTTPS.
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|
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Unless you plan to have a real CA generate your certs, you will need
|
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to generate a root cert and use that to sign the master, kubelet, and
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kubectl certs. How to do this is described in the [authentication
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documentation](/docs/concepts/cluster-administration/certificates/).
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You will end up with the following files (we will use these variables later on)
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- `CA_CERT`
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- put in on node where apiserver runs, for example in `/srv/kubernetes/ca.crt`.
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- `MASTER_CERT`
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- signed by CA_CERT
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- put in on node where apiserver runs, for example in `/srv/kubernetes/server.crt`
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- `MASTER_KEY `
|
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- put in on node where apiserver runs, for example in `/srv/kubernetes/server.key`
|
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- `KUBELET_CERT`
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- optional
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- `KUBELET_KEY`
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- optional
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#### Preparing Credentials
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The admin user (and any users) need:
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|
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- a token or a password to identify them.
|
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- tokens are just long alphanumeric strings, 32 chars for example. See
|
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- `TOKEN=$(dd if=/dev/urandom bs=128 count=1 2>/dev/null | base64 | tr -d "=+/[:space:]" | dd bs=32 count=1 2>/dev/null)`
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|
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Your tokens and passwords need to be stored in a file for the apiserver
|
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to read. This guide uses `/var/lib/kube-apiserver/known_tokens.csv`.
|
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The format for this file is described in the [authentication documentation](/docs/reference/access-authn-authz/authentication/#static-token-file).
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|
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For distributing credentials to clients, the convention in Kubernetes is to put the credentials
|
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into a [kubeconfig file](/docs/concepts/cluster-administration/authenticate-across-clusters-kubeconfig/).
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|
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The kubeconfig file for the administrator can be created as follows:
|
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|
||||
- If you have already used Kubernetes with a non-custom cluster (for example, used a Getting Started
|
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Guide), you will already have a `$HOME/.kube/config` file.
|
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- 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:
|
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- `kubectl config set-cluster $CLUSTER_NAME --server=http://$MASTER_IP --insecure-skip-tls-verify=true`
|
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- Otherwise, do this to set the apiserver ip, client certs, and user credentials.
|
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- `kubectl config set-cluster $CLUSTER_NAME --certificate-authority=$CA_CERT --embed-certs=true --server=https://$MASTER_IP`
|
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- `kubectl config set-credentials $USER --client-certificate=$CLI_CERT --client-key=$CLI_KEY --embed-certs=true --token=$TOKEN`
|
||||
- Set your cluster as the default cluster to use:
|
||||
- `kubectl config set-context $CONTEXT_NAME --cluster=$CLUSTER_NAME --user=$USER`
|
||||
- `kubectl config use-context $CONTEXT_NAME`
|
||||
|
||||
Next, make a kubeconfig file for the kubelets and kube-proxy. There are a couple of options for how
|
||||
many distinct files to make:
|
||||
|
||||
1. Use the same credential as the admin
|
||||
- This is simplest to setup.
|
||||
1. One token and kubeconfig file for all kubelets, one for all kube-proxy, one for admin.
|
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- This mirrors what is done on GCE today
|
||||
1. Different credentials for every kubelet, etc.
|
||||
- We are working on this but all the pieces are not ready yet.
|
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|
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You can make the files by copying the `$HOME/.kube/config` or by using the following template:
|
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|
||||
```yaml
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apiVersion: v1
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kind: Config
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||||
users:
|
||||
- name: kubelet
|
||||
user:
|
||||
token: ${KUBELET_TOKEN}
|
||||
clusters:
|
||||
- name: local
|
||||
cluster:
|
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certificate-authority: /srv/kubernetes/ca.crt
|
||||
contexts:
|
||||
- context:
|
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cluster: local
|
||||
user: kubelet
|
||||
name: service-account-context
|
||||
current-context: service-account-context
|
||||
```
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|
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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.
|
||||
|
||||
```shell
|
||||
iptables -t nat -F
|
||||
ip link set docker0 down
|
||||
ip link delete docker0
|
||||
```
|
||||
|
||||
The way you configure docker will depend in whether you have chosen the routable-vip or overlay-network approaches for your network.
|
||||
Some suggested docker options:
|
||||
|
||||
- create your own bridge for the per-node CIDR ranges, call it cbr0, and set `--bridge=cbr0` option on docker.
|
||||
- set `--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 (for example 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.
|
||||
- `--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.
|
||||
The minimum version required is [v0.5.6](https://github.com/coreos/rkt/releases/tag/v0.5.6).
|
||||
|
||||
[systemd](http://www.freedesktop.org/wiki/Software/systemd/) is required on your node to run rkt. The
|
||||
minimum version required to match rkt v0.5.6 is
|
||||
[systemd 215](http://lists.freedesktop.org/archives/systemd-devel/2014-July/020903.html).
|
||||
|
||||
[rkt metadata service](https://github.com/coreos/rkt/blob/master/Documentation/networking/overview.md) is also required
|
||||
for rkt networking support. You can start rkt metadata service by using command like
|
||||
`sudo systemd-run rkt metadata-service`
|
||||
|
||||
Then you need to configure your kubelet with flag:
|
||||
|
||||
- `--container-runtime=rkt`
|
||||
|
||||
### kubelet
|
||||
|
||||
All nodes should run kubelet. See [Software Binaries](#software-binaries).
|
||||
|
||||
Arguments to consider:
|
||||
|
||||
- If following the HTTPS security approach:
|
||||
- `--kubeconfig=/var/lib/kubelet/kubeconfig`
|
||||
- Otherwise, if taking the firewall-based security approach
|
||||
- `--config=/etc/kubernetes/manifests`
|
||||
- `--cluster-dns=` to the address of the DNS server you will setup (see [Starting Cluster Services](#starting-cluster-services).)
|
||||
- `--cluster-domain=` to the dns domain prefix to use for cluster DNS addresses.
|
||||
- `--docker-root=`
|
||||
- `--root-dir=`
|
||||
- `--pod-cidr=` The CIDR to use for pod IP addresses, only used in standalone mode. In cluster mode, this is obtained from the master.
|
||||
- `--register-node` (described in [Node](/docs/admin/node/) 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:
|
||||
- `--master=https://$MASTER_IP`
|
||||
- `--kubeconfig=/var/lib/kube-proxy/kubeconfig`
|
||||
- Otherwise, if taking the firewall-based security approach
|
||||
- `--master=http://$MASTER_IP`
|
||||
|
||||
Note that on some Linux platforms, you may need to manually install the
|
||||
`conntrack` package which is a dependency of kube-proxy, or else kube-proxy
|
||||
cannot be started successfully.
|
||||
|
||||
For more details about debugging kube-proxy problems, refer to
|
||||
[Debug Services](/docs/tasks/debug-application-cluster/debug-service/)
|
||||
|
||||
### Networking
|
||||
|
||||
Each node needs to be allocated its own CIDR range for pod networking.
|
||||
Call this `NODE_X_POD_CIDR`.
|
||||
|
||||
A bridge called `cbr0` needs to be created on each node. The bridge is explained
|
||||
further in the [networking documentation](/docs/concepts/cluster-administration/networking/). The bridge itself
|
||||
needs an address from `$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.
|
||||
|
||||
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:
|
||||
|
||||
```shell
|
||||
iptables -t nat -A POSTROUTING ! -d ${CLUSTER_SUBNET} -m addrtype ! --dst-type LOCAL -j MASQUERADE
|
||||
```
|
||||
|
||||
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 (for example using [logrotate](http://linux.die.net/man/8/logrotate)).
|
||||
- Setup liveness-monitoring (for example using [supervisord](http://supervisord.org/)).
|
||||
- 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 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.
|
||||
|
||||
- Highly available and easy to restore - Run 3 or 5 etcd instances with, their logs written to a directory backed
|
||||
by durable storage (RAID, GCE PD)
|
||||
- Not highly available, but easy to restore - Run one etcd instance, with its log written to a directory backed
|
||||
by durable storage (RAID, GCE PD).
|
||||
|
||||
{{< note >}}May result in operations outages in case of
|
||||
instance outage. {{< /note >}}
|
||||
- Highly available - Run 3 or 5 etcd instances with non durable storage.
|
||||
|
||||
{{< note >}}Log can be written to non-durable storage
|
||||
because storage is replicated.{{< /note >}}
|
||||
|
||||
See [cluster-troubleshooting](/docs/admin/cluster-troubleshooting/) for more discussion on factors affecting cluster
|
||||
availability.
|
||||
|
||||
To run an etcd instance:
|
||||
|
||||
1. Copy [`cluster/gce/manifests/etcd.manifest`](https://github.com/kubernetes/kubernetes/blob/master/cluster/gce/manifests/etcd.manifest)
|
||||
1. Make any modifications needed
|
||||
1. Start the pod by putting it into the kubelet manifest directory
|
||||
|
||||
### Apiserver, Controller Manager, and Scheduler
|
||||
|
||||
The apiserver, controller manager, and scheduler will each run as a pod on the master node.
|
||||
|
||||
For each of these components, the steps to start them running are similar:
|
||||
|
||||
1. Start with a provided template for a pod.
|
||||
1. Set the `HYPERKUBE_IMAGE` to the values chosen in [Selecting Images](#selecting-images).
|
||||
1. Determine which flags are needed for your cluster, using the advice below each template.
|
||||
1. Set the flags to be individual strings in the command array (for example $ARGN below)
|
||||
1. Start the pod by putting the completed template into the kubelet manifest directory.
|
||||
1. Verify that the pod is started.
|
||||
|
||||
#### Apiserver pod template
|
||||
|
||||
```json
|
||||
{
|
||||
"kind": "Pod",
|
||||
"apiVersion": "v1",
|
||||
"metadata": {
|
||||
"name": "kube-apiserver"
|
||||
},
|
||||
"spec": {
|
||||
"hostNetwork": true,
|
||||
"containers": [
|
||||
{
|
||||
"name": "kube-apiserver",
|
||||
"image": "${HYPERKUBE_IMAGE}",
|
||||
"command": [
|
||||
"/hyperkube",
|
||||
"apiserver",
|
||||
"$ARG1",
|
||||
"$ARG2",
|
||||
...
|
||||
"$ARGN"
|
||||
],
|
||||
"ports": [
|
||||
{
|
||||
"name": "https",
|
||||
"hostPort": 443,
|
||||
"containerPort": 443
|
||||
},
|
||||
{
|
||||
"name": "local",
|
||||
"hostPort": 8080,
|
||||
"containerPort": 8080
|
||||
}
|
||||
],
|
||||
"volumeMounts": [
|
||||
{
|
||||
"name": "srvkube",
|
||||
"mountPath": "/srv/kubernetes",
|
||||
"readOnly": true
|
||||
},
|
||||
{
|
||||
"name": "etcssl",
|
||||
"mountPath": "/etc/ssl",
|
||||
"readOnly": true
|
||||
}
|
||||
],
|
||||
"livenessProbe": {
|
||||
"httpGet": {
|
||||
"scheme": "HTTP",
|
||||
"host": "127.0.0.1",
|
||||
"port": 8080,
|
||||
"path": "/healthz"
|
||||
},
|
||||
"initialDelaySeconds": 15,
|
||||
"timeoutSeconds": 15
|
||||
}
|
||||
}
|
||||
],
|
||||
"volumes": [
|
||||
{
|
||||
"name": "srvkube",
|
||||
"hostPath": {
|
||||
"path": "/srv/kubernetes"
|
||||
}
|
||||
},
|
||||
{
|
||||
"name": "etcssl",
|
||||
"hostPath": {
|
||||
"path": "/etc/ssl"
|
||||
}
|
||||
}
|
||||
]
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Here are some apiserver flags you may need to set:
|
||||
|
||||
- `--cloud-provider=` see [cloud providers](#cloud-providers)
|
||||
- `--cloud-config=` see [cloud providers](#cloud-providers)
|
||||
- `--address=${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.
|
||||
- `--service-cluster-ip-range=$SERVICE_CLUSTER_IP_RANGE`
|
||||
- `--etcd-servers=http://127.0.0.1:4001`
|
||||
- `--tls-cert-file=/srv/kubernetes/server.cert`
|
||||
- `--tls-private-key-file=/srv/kubernetes/server.key`
|
||||
- `--enable-admission-plugins=$RECOMMENDED_LIST`
|
||||
- See [admission controllers](/docs/reference/access-authn-authz/admission-controllers/) 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`
|
||||
|
||||
This pod mounts several node file system directories using the `hostPath` volumes. Their purposes are:
|
||||
|
||||
- The `/etc/ssl` mount allows the apiserver to find the SSL root certs so it can
|
||||
authenticate external services, such as a cloud provider.
|
||||
- This is not required if you do not use a cloud provider (bare-metal for example).
|
||||
- The `/srv/kubernetes` mount allows the apiserver to read certs and credentials stored on the
|
||||
node disk. These could instead be stored on a persistent disk, such as a GCE PD, or baked into the image.
|
||||
- Optionally, you may want to mount `/var/log` as well and redirect output there (not shown in template).
|
||||
- Do this if you prefer your logs to be accessible from the root filesystem with tools like journalctl.
|
||||
|
||||
*TODO* document proxy-ssh setup.
|
||||
|
||||
##### Cloud Providers
|
||||
|
||||
Apiserver supports several cloud providers.
|
||||
|
||||
- options for `--cloud-provider` flag are `aws`, `azure`, `cloudstack`, `fake`, `gce`, `mesos`, `openstack`, `ovirt`, `rackspace`, `vsphere`, or unset.
|
||||
- unset used for bare metal setups.
|
||||
- support for new IaaS is added by contributing code [here](https://releases.k8s.io/{{< param "githubbranch" >}}/pkg/cloudprovider/providers)
|
||||
|
||||
Some cloud providers require a config file. If so, you need to put config file into apiserver image or mount through hostPath.
|
||||
|
||||
- `--cloud-config=` set if cloud provider requires a config file.
|
||||
- Used by `aws`, `gce`, `mesos`, `openstack`, `ovirt` and `rackspace`.
|
||||
- You must put config file into apiserver image or mount through hostPath.
|
||||
- Cloud config file syntax is [Gcfg](https://code.google.com/p/gcfg/).
|
||||
- AWS format defined by type [AWSCloudConfig](https://releases.k8s.io/{{< param "githubbranch" >}}/pkg/cloudprovider/providers/aws/aws.go)
|
||||
- There is a similar type in the corresponding file for other cloud providers.
|
||||
|
||||
#### Scheduler pod template
|
||||
|
||||
Complete this template for the scheduler pod:
|
||||
|
||||
```json
|
||||
{
|
||||
"kind": "Pod",
|
||||
"apiVersion": "v1",
|
||||
"metadata": {
|
||||
"name": "kube-scheduler"
|
||||
},
|
||||
"spec": {
|
||||
"hostNetwork": true,
|
||||
"containers": [
|
||||
{
|
||||
"name": "kube-scheduler",
|
||||
"image": "$HYPERKUBE_IMAGE",
|
||||
"command": [
|
||||
"/hyperkube",
|
||||
"scheduler",
|
||||
"--master=127.0.0.1:8080",
|
||||
"$SCHEDULER_FLAG1",
|
||||
...
|
||||
"$SCHEDULER_FLAGN"
|
||||
],
|
||||
"livenessProbe": {
|
||||
"httpGet": {
|
||||
"scheme": "HTTP",
|
||||
"host": "127.0.0.1",
|
||||
"port": 10251,
|
||||
"path": "/healthz"
|
||||
},
|
||||
"initialDelaySeconds": 15,
|
||||
"timeoutSeconds": 15
|
||||
}
|
||||
}
|
||||
]
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Typically, no additional flags are required for the scheduler.
|
||||
|
||||
Optionally, you may want to mount `/var/log` as well and redirect output there.
|
||||
|
||||
#### Controller Manager Template
|
||||
|
||||
Template for controller manager pod:
|
||||
|
||||
```json
|
||||
{
|
||||
"kind": "Pod",
|
||||
"apiVersion": "v1",
|
||||
"metadata": {
|
||||
"name": "kube-controller-manager"
|
||||
},
|
||||
"spec": {
|
||||
"hostNetwork": true,
|
||||
"containers": [
|
||||
{
|
||||
"name": "kube-controller-manager",
|
||||
"image": "$HYPERKUBE_IMAGE",
|
||||
"command": [
|
||||
"/hyperkube",
|
||||
"controller-manager",
|
||||
"$CNTRLMNGR_FLAG1",
|
||||
...
|
||||
"$CNTRLMNGR_FLAGN"
|
||||
],
|
||||
"volumeMounts": [
|
||||
{
|
||||
"name": "srvkube",
|
||||
"mountPath": "/srv/kubernetes",
|
||||
"readOnly": true
|
||||
},
|
||||
{
|
||||
"name": "etcssl",
|
||||
"mountPath": "/etc/ssl",
|
||||
"readOnly": true
|
||||
}
|
||||
],
|
||||
"livenessProbe": {
|
||||
"httpGet": {
|
||||
"scheme": "HTTP",
|
||||
"host": "127.0.0.1",
|
||||
"port": 10252,
|
||||
"path": "/healthz"
|
||||
},
|
||||
"initialDelaySeconds": 15,
|
||||
"timeoutSeconds": 15
|
||||
}
|
||||
}
|
||||
],
|
||||
"volumes": [
|
||||
{
|
||||
"name": "srvkube",
|
||||
"hostPath": {
|
||||
"path": "/srv/kubernetes"
|
||||
}
|
||||
},
|
||||
{
|
||||
"name": "etcssl",
|
||||
"hostPath": {
|
||||
"path": "/etc/ssl"
|
||||
}
|
||||
}
|
||||
]
|
||||
}
|
||||
}
|
||||
```
|
||||
|
||||
Flags to consider using with controller manager:
|
||||
|
||||
- `--cluster-cidr=`, the CIDR range for pods in cluster.
|
||||
- `--allocate-node-cidrs=`, if you are using `--cloud-provider=`, allocate and set the CIDRs for pods on the cloud provider.
|
||||
- `--cloud-provider=` and `--cloud-config` as described in apiserver section.
|
||||
- `--service-account-private-key-file=/srv/kubernetes/server.key`, used by the [service account](/docs/user-guide/service-accounts) feature.
|
||||
- `--master=127.0.0.1:8080`
|
||||
|
||||
#### Starting and Verifying Apiserver, Scheduler, and Controller Manager
|
||||
|
||||
Place each completed pod template into the kubelet config dir
|
||||
(whatever `--config=` argument of kubelet is set to, typically
|
||||
`/etc/kubernetes/manifests`). The order does not matter: scheduler and
|
||||
controller manager will retry reaching the apiserver until it is up.
|
||||
|
||||
Use `ps` or `docker ps` to verify that each process has started. For example, verify that kubelet has started a container for the apiserver like this:
|
||||
|
||||
```shell
|
||||
$ sudo docker ps | grep apiserver
|
||||
5783290746d5 k8s.gcr.io/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:
|
||||
|
||||
```shell
|
||||
$ echo $(curl -s http://localhost:8080/healthz)
|
||||
ok
|
||||
$ curl -s http://localhost:8080/api
|
||||
{
|
||||
"versions": [
|
||||
"v1"
|
||||
]
|
||||
}
|
||||
```
|
||||
|
||||
If you have selected the `--register-node=true` option for kubelets, they will now begin self-registering with the apiserver.
|
||||
You should soon be able to see all your nodes by running the `kubectl get nodes` command.
|
||||
Otherwise, you will need to manually create node objects.
|
||||
|
||||
### Starting Cluster Services
|
||||
|
||||
You will want to complete your Kubernetes clusters by adding cluster-wide
|
||||
services. These are sometimes called *addons*, and [an overview
|
||||
of their purpose is in the admin guide](/docs/admin/cluster-components/#addons).
|
||||
|
||||
Notes for setting up each cluster service are given below:
|
||||
|
||||
* Cluster DNS:
|
||||
* Required for many Kubernetes examples
|
||||
* [Setup instructions](http://releases.k8s.io/{{< param "githubbranch" >}}/cluster/addons/dns/)
|
||||
* [Admin Guide](/docs/concepts/services-networking/dns-pod-service/)
|
||||
* Cluster-level Logging
|
||||
* [Cluster-level Logging Overview](/docs/user-guide/logging/overview/)
|
||||
* [Cluster-level Logging with Elasticsearch](/docs/user-guide/logging/elasticsearch/)
|
||||
* [Cluster-level Logging with Stackdriver Logging](/docs/user-guide/logging/stackdriver/)
|
||||
* Container Resource Monitoring
|
||||
* [Setup instructions](http://releases.k8s.io/{{< param "githubbranch" >}}/cluster/addons/cluster-monitoring/)
|
||||
* GUI
|
||||
* [Setup instructions](https://github.com/kubernetes/dashboard)
|
||||
|
||||
## Troubleshooting
|
||||
|
||||
### Running validate-cluster
|
||||
|
||||
`cluster/validate-cluster.sh` is used by `cluster/kube-up.sh` to determine if
|
||||
the cluster start succeeded.
|
||||
|
||||
Example usage and output:
|
||||
|
||||
```shell
|
||||
KUBECTL_PATH=$(which kubectl) NUM_NODES=3 KUBERNETES_PROVIDER=local cluster/validate-cluster.sh
|
||||
Found 3 node(s).
|
||||
NAME STATUS AGE VERSION
|
||||
node1.local Ready 1h v1.6.9+a3d1dfa6f4335
|
||||
node2.local Ready 1h v1.6.9+a3d1dfa6f4335
|
||||
node3.local Ready 1h v1.6.9+a3d1dfa6f4335
|
||||
Validate output:
|
||||
NAME STATUS MESSAGE ERROR
|
||||
controller-manager Healthy ok
|
||||
scheduler Healthy ok
|
||||
etcd-1 Healthy {"health": "true"}
|
||||
etcd-2 Healthy {"health": "true"}
|
||||
etcd-0 Healthy {"health": "true"}
|
||||
Cluster validation succeeded
|
||||
```
|
||||
|
||||
### Inspect pods and services
|
||||
|
||||
Try to run through the "Inspect your cluster" section in one of the other Getting Started Guides, such as [GCE](/docs/setup/turnkey/gce/#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/application/deployment.yaml).
|
||||
|
||||
### Running the Conformance Test
|
||||
|
||||
You may want to try to run the [Conformance test](http://releases.k8s.io/{{< param "githubbranch" >}}/test/e2e_node/conformance/run_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, see the section on [troubleshooting](/docs/setup/turnkey/gce/#troubleshooting), post to the
|
||||
[Kubernetes Forum](https://discuss.kubernetes.io), or come ask questions on [Slack](/docs/troubleshooting#slack).
|
||||
|
||||
## Support Level
|
||||
|
||||
|
||||
IaaS Provider | Config. Mgmt | OS | Networking | Docs | Conforms | Support Level
|
||||
-------------------- | ------------ | ------ | ---------- | --------------------------------------------- | ---------| ----------------------------
|
||||
any | any | any | any | [docs](/docs/getting-started-guides/scratch/) | | Community ([@erictune](https://github.com/erictune))
|
||||
|
||||
|
||||
For support level information on all solutions, see the [Table of solutions](/docs/getting-started-guides/#table-of-solutions/) chart.
|
||||
Reference in New Issue
Block a user