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Signed-off-by: Joe Beda <joe.github@bedafamily.com>
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Joe Beda
2017-03-12 14:25:44 -07:00
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@@ -13,39 +13,50 @@ li>.highlighter-rouge {position:relative; top:3px;}
## Overview
This quickstart shows you how to easily install a secure Kubernetes cluster on machines running Ubuntu 16.04, CentOS 7 or HypriotOS v1.0.1+.
The installation uses a tool called `kubeadm` which is part of Kubernetes.
This quickstart shows you how to easily install a secure Kubernetes cluster on
machines running Ubuntu 16.04, CentOS 7 or HypriotOS v1.0.1+. The installation
uses a tool called _kubeadm_ which is part of Kubernetes.
This process works with local VMs, physical servers and/or cloud servers.
It is simple enough that you can easily integrate its use into your own automation (Terraform, Chef, Puppet, etc).
This process works with local VMs, physical servers and/or cloud servers. It is
simple enough that you can easily integrate its use into your own automation
(Terraform, Chef, Puppet, etc).
See the full `kubeadm` [reference](/docs/admin/kubeadm) for information on all `kubeadm` command-line flags and for advice on automating `kubeadm` itself.
See the full [kubeadm reference](/docs/admin/kubeadm) for information on all
kubeadm command-line flags and for advice on automating kubeadm itself.
**The `kubeadm` tool is currently in alpha but please try it out and give us [feedback](/docs/getting-started-guides/kubeadm/#feedback)!
Be sure to read the [limitations](#limitations); in particular note that kubeadm doesn't have great support for
automatically configuring cloud providers. Please refer to the specific cloud provider documentation or
use another provisioning system.**
**The kubeadm tool is currently in alpha but please try it out and give us
[feedback](/docs/getting-started-guides/kubeadm/#feedback)! Be sure to read the
[limitations](#limitations); in particular note that kubeadm doesn't have great
support for automatically configuring cloud providers. Please refer to the
specific cloud provider documentation or use another provisioning system.**
kubeadm assumes you have a set of machines (virtual or real) that are up and running. It is designed
to be part of a large provisioning system - or just for easy manual provisioning. kubeadm is a great
choice where you have your own infrastructure (e.g. bare metal), or where you have an existing
orchestration system (e.g. Puppet) that you have to integrate with.
kubeadm assumes you have a set of machines (virtual or real) that are up and
running. It is designed to be part of a large provisioning system - or just for
easy manual provisioning. kubeadm is a great choice where you have your own
infrastructure (e.g. bare metal), or where you have an existing orchestration
system (e.g. Puppet) that you have to integrate with.
If you are not constrained, there are some other tools built to give you complete clusters:
If you are not constrained, there are some other tools built to give you
complete clusters:
* On GCE, [Google Container Engine](https://cloud.google.com/container-engine/) gives you one-click Kubernetes clusters
* On AWS, [kops](https://github.com/kubernetes/kops) makes cluster installation and management easy (and supports high availability)
* On GCE, [Google Container Engine](https://cloud.google.com/container-engine/)
gives you one-click Kubernetes clusters
* On AWS, [kops](https://github.com/kubernetes/kops) makes cluster installation
and management easy (and supports high availability)
## Prerequisites
1. One or more machines running Ubuntu 16.04+, CentOS 7 or HypriotOS v1.0.1+
1. 1GB or more of RAM per machine (any less will leave little room for your apps)
1. Full network connectivity between all machines in the cluster (public or private network is fine)
1. 1GB or more of RAM per machine (any less will leave little room for your
apps)
1. Full network connectivity between all machines in the cluster (public or
private network is fine)
## Objectives
* Install a secure Kubernetes cluster on your machines
* Install a pod network on the cluster so that application components (pods) can talk to each other
* Install a pod network on the cluster so that application components (pods) can
talk to each other
* Install a sample microservices application (a socks shop) on the cluster
## Instructions
@@ -54,155 +65,209 @@ If you are not constrained, there are some other tools built to give you complet
You will install the following packages on all the machines:
* `docker`: the container runtime, which Kubernetes depends on. v1.11.2 is recommended, but v1.10.3 and v1.12.1 are known to work as well.
* `kubelet`: the most core component of Kubernetes.
It runs on all of the machines in your cluster and does things like starting pods and containers.
* `kubectl`: the command to control the cluster once it's running.
You will only need this on the master, but it can be useful to have on the other nodes as well.
* `docker`: the container runtime, which Kubernetes depends on. v1.11.2 is
recommended, but v1.10.3 and v1.12.1 are known to work as well.
* `kubelet`: the most core component of Kubernetes. It runs on all of the
machines in your cluster and does things like starting pods and containers.
* `kubectl`: the command to control the cluster once it's running. You will only
need this on the master, but it can be useful to have on the other nodes as
well.
* `kubeadm`: the command to bootstrap the cluster.
NOTE: If you already have kubeadm installed, you should do a `apt-get update && apt-get upgrade` or `yum update` to get the latest version of kubeadm.
See the reference doc if you want to read about the different [kubeadm releases](https://github.com/kubernetes/kubeadm/blob/master/CHANGELOG.md)
NOTE: If you already have kubeadm installed, you should do a `apt-get update &&
apt-get upgrade` or `yum update` to get the latest version of kubeadm. See the
reference doc if you want to read about the different [kubeadm
releases](https://github.com/kubernetes/kubeadm/blob/master/CHANGELOG.md)
For each host in turn:
* SSH into the machine and become `root` if you are not already (for example, run `sudo su -`).
* SSH into the machine and become root if you are not already (for example,
run `sudo su -`).
* If the machine is running Ubuntu or HypriotOS, run:
apt-get update && apt-get install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
# Install docker if you don't have it already.
apt-get install -y docker.io
apt-get install -y kubelet kubeadm kubectl kubernetes-cni
``` bash
apt-get update && apt-get install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | apt-key add -
cat <<EOF > /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
EOF
apt-get update
# Install docker if you don't have it already.
apt-get install -y docker.io
apt-get install -y kubelet kubeadm kubectl kubernetes-cni
```
If the machine is running CentOS, run:
If the machine is running CentOS, run:
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://yum.kubernetes.io/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
setenforce 0
yum install -y docker kubelet kubeadm kubectl kubernetes-cni
systemctl enable docker && systemctl start docker
systemctl enable kubelet && systemctl start kubelet
``` bash
cat <<EOF > /etc/yum.repos.d/kubernetes.repo
[kubernetes]
name=Kubernetes
baseurl=http://yum.kubernetes.io/repos/kubernetes-el7-x86_64
enabled=1
gpgcheck=1
repo_gpgcheck=1
gpgkey=https://packages.cloud.google.com/yum/doc/yum-key.gpg
https://packages.cloud.google.com/yum/doc/rpm-package-key.gpg
EOF
setenforce 0
yum install -y docker kubelet kubeadm kubectl kubernetes-cni
systemctl enable docker && systemctl start docker
systemctl enable kubelet && systemctl start kubelet
```
The kubelet is now restarting every few seconds, as it waits in a crashloop for `kubeadm` to tell it what to do.
The kubelet is now restarting every few seconds, as it waits in a crashloop for
kubeadm to tell it what to do.
Note: Disabling SELinux by running `setenforce 0` is required in order to allow containers to access the host filesystem, which is required by pod networks for example. You have to do this until kubelet can handle SELinux better.
Note: Disabling SELinux by running `setenforce 0` is required in order to allow
containers to access the host filesystem, which is required by pod networks for
example. You have to do this until kubelet can handle SELinux better.
### (2/4) Initializing your master
The master is the machine where the "control plane" components run, including `etcd` (the cluster database) and the API server (which the `kubectl` CLI communicates with).
All of these components run in pods started by `kubelet` and the following images are required and will be automatically pulled by `kubelet` if they are absent while `kubeadm init` is initializing your master:
The master is the machine where the "control plane" components run, including
etcd (the cluster database) and the API server (which the kubectl CLI
communicates with). All of these components run in pods started by kubelet and
the following images are required and will be automatically pulled by kubelet
if they are absent while `kubeadm init` is initializing your master:
gcr.io/google_containers/kube-proxy-amd64 v1.5.3
gcr.io/google_containers/kube-controller-manager-amd64 v1.5.3
gcr.io/google_containers/kube-scheduler-amd64 v1.5.3
gcr.io/google_containers/kube-apiserver-amd64 v1.5.3
gcr.io/google_containers/etcd-amd64 3.0.14-kubeadm
gcr.io/google_containers/kube-discovery-amd64 1.0
gcr.io/google_containers/pause-amd64 3.0
| Image Name | Version |
|---|---|
| gcr.io/google_containers/kube-proxy-amd64 | v1.5.3
| gcr.io/google_containers/kube-controller-manager-amd64 | v1.5.3
| gcr.io/google_containers/kube-scheduler-amd64 | v1.5.3
| gcr.io/google_containers/kube-apiserver-amd64 | v1.5.3
| gcr.io/google_containers/etcd-amd64 | 3.0.14-kubeadm
| gcr.io/google_containers/kube-discovery-amd64 | 1.0
| gcr.io/google_containers/pause-amd64 | 3.0
Right now you can't run `kubeadm init` twice without tearing down the cluster in between, see [Tear down](#tear-down).
Right now you can't run `kubeadm init` twice without tearing down the cluster in
between, see [Tear down](#tear-down).
If you try to run `kubeadm init` and your machine is in a state that is incompatible with starting a Kubernetes cluster, `kubeadm` will warn you about things that might not work or it will error out for unsatisfied mandatory requirements.
If you try to run `kubeadm init` and your machine is in a state that is
incompatible with starting a Kubernetes cluster, kubeadm will warn you about
things that might not work or it will error out for unsatisfied mandatory
requirements.
To initialize the master, pick one of the machines you previously installed `kubelet` and `kubeadm` on, and run:
To initialize the master, pick one of the machines you previously installed
kubelet and kubeadm on, and run:
# kubeadm init
``` bash
kubeadm init
```
**Note:** this will autodetect the network interface to advertise the master on as the interface with the default gateway.
If you want to use a different interface, specify `--api-advertise-addresses <ip-address>` argument to `kubeadm init`.
**Note:** this will autodetect the network interface to advertise the master on
as the interface with the default gateway. If you want to use a different
interface, specify `--api-advertise-addresses <ip-address>` argument to `kubeadm
init`.
If you want to use [flannel](https://github.com/coreos/flannel) as the pod network, specify `--pod-network-cidr 10.244.0.0/16` if you're using the daemonset manifest below. _However, please note that this is not required for any other networks besides Flannel._
If you want to use [flannel](https://github.com/coreos/flannel) as the pod
network, specify `--pod-network-cidr 10.244.0.0/16` if you're using the
daemonset manifest below. _However, please note that this is not required for
any other networks besides Flannel._
Please refer to the [kubeadm reference doc](/docs/admin/kubeadm/) if you want to read more about the flags `kubeadm init` provides.
Please refer to the [kubeadm reference doc](/docs/admin/kubeadm/) if you want to
read more about the flags `kubeadm init` provides.
This will download and install the cluster database and "control plane" components.
This may take several minutes.
This will download and install the cluster database and "control plane"
components. This may take several minutes.
The output should look like:
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[init] Using Kubernetes version: v1.5.1
[tokens] Generated token: "064158.548b9ddb1d3fad3e"
[certificates] Generated Certificate Authority key and certificate.
[certificates] Generated API Server key and certificate
[certificates] Generated Service Account signing keys
[certificates] Created keys and certificates in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 61.317580 seconds
[apiclient] Waiting for at least one node to register and become ready
[apiclient] First node is ready after 6.556101 seconds
[apiclient] Creating a test deployment
[apiclient] Test deployment succeeded
[token-discovery] Created the kube-discovery deployment, waiting for it to become ready
[token-discovery] kube-discovery is ready after 6.020980 seconds
[addons] Created essential addon: kube-proxy
[addons] Created essential addon: kube-dns
```
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[init] Using Kubernetes version: v1.5.1
[tokens] Generated token: "064158.548b9ddb1d3fad3e"
[certificates] Generated Certificate Authority key and certificate.
[certificates] Generated API Server key and certificate
[certificates] Generated Service Account signing keys
[certificates] Created keys and certificates in "/etc/kubernetes/pki"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/admin.conf"
[apiclient] Created API client, waiting for the control plane to become ready
[apiclient] All control plane components are healthy after 61.317580 seconds
[apiclient] Waiting for at least one node to register and become ready
[apiclient] First node is ready after 6.556101 seconds
[apiclient] Creating a test deployment
[apiclient] Test deployment succeeded
[token-discovery] Created the kube-discovery deployment, waiting for it to become ready
[token-discovery] kube-discovery is ready after 6.020980 seconds
[addons] Created essential addon: kube-proxy
[addons] Created essential addon: kube-dns
Your Kubernetes master has initialized successfully!
Your Kubernetes master has initialized successfully!
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
http://kubernetes.io/docs/admin/addons/
You should now deploy a pod network to the cluster.
Run "kubectl apply -f [podnetwork].yaml" with one of the options listed at:
http://kubernetes.io/docs/admin/addons/
You can now join any number of machines by running the following on each node:
You can now join any number of machines by running the following on each node:
kubeadm join --token=<token> <master-ip>
kubeadm join --token=<token> <master-ip>
```
Make a record of the `kubeadm join` command that `kubeadm init` outputs.
You will need this in a moment.
The key included here is secret, keep it safe &mdash; anyone with this key can add authenticated nodes to your cluster.
Make a record of the `kubeadm join` command that `kubeadm init` outputs. You
will need this in a moment. The key included here is secret, keep it safe
&mdash; anyone with this key can add authenticated nodes to your cluster.
The key is used for mutual authentication between the master and the joining nodes.
By default, your cluster will not schedule pods on the master for security reasons.
If you want to be able to schedule pods on the master, for example if you want a single-machine Kubernetes cluster for development, run:
By default, your cluster will not schedule pods on the master for security
reasons. If you want to be able to schedule pods on the master, for example if
you want a single-machine Kubernetes cluster for development, run:
# kubectl taint nodes --all dedicated-
node "test-01" tainted
taint key="dedicated" and effect="" not found.
taint key="dedicated" and effect="" not found.
``` bash
kubectl taint nodes --all dedicated-
```
This will remove the "dedicated" taint from any nodes that have it, including the master node, meaning that the scheduler will then be able to schedule pods everywhere.
With output looking something like:
```
node "test-01" tainted
taint key="dedicated" and effect="" not found.
taint key="dedicated" and effect="" not found.
```
This will remove the "dedicated" taint from any nodes that have it, including
the master node, meaning that the scheduler will then be able to schedule pods
everywhere.
### (3/4) Installing a pod network
You must install a pod network add-on so that your pods can communicate with each other.
You must install a pod network add-on so that your pods can communicate with
each other.
**It is necessary to do this before you try to deploy any applications to your cluster, and before `kube-dns` will start up. Note also that `kubeadm` only supports CNI based networks and therefore kubenet based networks will not work.**
**It is necessary to do this before you try to deploy any applications to your
cluster. Also, kube-dns, a helper service, will no start up before a network is
installed. Note also that kubeadm only supports CNI based networks and therefore
kubenet based networks will not work.**
Several projects provide Kubernetes pod networks using CNI, some of which
also support [Network Policy](/docs/user-guide/networkpolicies/). See the [add-ons page](/docs/admin/addons/) for a complete list of available network add-ons.
Several projects provide Kubernetes pod networks using CNI, some of which also
support [Network Policy](/docs/user-guide/networkpolicies/). See the [add-ons
page](/docs/admin/addons/) for a complete list of available network add-ons.
You can install a pod network add-on with the following command:
You can install a pod network add-on with the following command:
# kubectl apply -f <add-on.yaml>
``` bash
kubectl apply -f <add-on.yaml>
```
Please refer to the specific add-on installation guide for exact details. You should only install one pod network per cluster.
Please refer to the specific add-on installation guide for exact details. You
should only install one pod network per cluster.
If you are on another architecture than amd64, you should use the flannel overlay network as described in [the multi-platform section](#kubeadm-is-multi-platform)
If you are on another architecture than amd64, you should use the flannel
overlay network as described in [the multi-platform
section](#kubeadm-is-multi-platform)
NOTE: You can install **only one** pod network per cluster.
Once a pod network has been installed, you can confirm that it is working by checking that the `kube-dns` pod is `Running` in the output of `kubectl get pods --all-namespaces`.
And once the `kube-dns` pod is up and running, you can continue by joining your nodes.
Once a pod network has been installed, you can confirm that it is working by
checking that the kube-dns pod is `Running` in the output of `kubectl get pods
--all-namespaces`.
And once the kube-dns pod is up and running, you can continue by joining your
nodes.
You may have trouble in the configuration if you see the following statuses
@@ -213,199 +278,298 @@ kube-system canal-node-77d0h 2/3 CrashLoopBackOff 3
kube-system kube-dns-2924299975-7q1vq 0/4 ContainerCreating 0 15m
```
The three statuses ```RunContainerError``` and ```CrashLoopBackOff``` and ```ContainerCreating``` are very common.
The three statuses ```RunContainerError``` and ```CrashLoopBackOff``` and
```ContainerCreating``` are very common.
To help diagnose what happened, you can use the following command to check what is in the logs:
To help diagnose what happened, you can use the following command to check what
is in the logs:
```bash
``` bash
kubectl describe -n kube-system po {YOUR_POD_NAME}
```
Do not using kubectl logs. You will got the following error:
Do not using kubectl logs. If you run:
``` bash
kubectl logs -n kube-system canal-node-f0lqp
```
You will got the following error:
```
# kubectl logs -n kube-system canal-node-f0lqp
Error from server (BadRequest): the server rejected our request for an unknown reason (get pods canal-node-f0lqp)
```
The ```kubectl describe``` comand gives you more details about the logs
The ```kubectl describe``` comand gives you more details about what went wrong.
``` bash
kubectl describe -n kube-system po kube-dns-2924299975-1l2t7
```
The events should show something like this:
```
# kubectl describe -n kube-system po kube-dns-2924299975-1l2t7
2m 2m 1 {kubelet nac} spec.containers{flannel} Warning Failed Failed to start container with docker id 927e7ccdc32b with error: Error response from daemon: {"message":"chown /etc/resolv.conf: operation not permitted"}
```
Or
Or this:
```
6m 1m 191 {kubelet nac} Warning FailedSync Error syncing pod, skipping: failed to "SetupNetwork" for "kube-dns-2924299975-1l2t7_kube-system" with SetupNetworkError: "Failed to setup network for pod \"kube-dns-2924299975-1l2t7_kube-system(dee8ef21-fbcb-11e6-ba19-38d547e0006a)\" using network plugins \"cni\": open /run/flannel/subnet.env: no such file or directory; Skipping pod"
```
You can then do some Google searches on the error messages, which may help you to find some solutions.
You can then do some Google searches on the error messages, which may help you
to find some solutions.
### (4/4) Joining your nodes
The nodes are where your workloads (containers and pods, etc) run.
If you want to add any new machines as nodes to your cluster, for each machine: SSH to that machine, become root (e.g. `sudo su -`) and run the command that was output by `kubeadm init`.
For example:
The nodes are where your workloads (containers and pods, etc) run. If you want
to add any new machines as nodes to your cluster, for each machine: SSH to that
machine, become root (e.g. `sudo su -`) and run the command that was output by
`kubeadm init`. For example:
# kubeadm join --token <token> <master-ip>
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] Starting the kubelet service
[tokens] Validating provided token
[discovery] Created cluster info discovery client, requesting info from "http://192.168.x.y:9898/cluster-info/v1/?token-id=f11877"
[discovery] Cluster info object received, verifying signature using given token
[discovery] Cluster info signature and contents are valid, will use API endpoints [https://192.168.x.y:6443]
[bootstrap] Trying to connect to endpoint https://192.168.x.y:6443
[bootstrap] Detected server version: v1.5.1
[bootstrap] Successfully established connection with endpoint "https://192.168.x.y:6443"
[csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request
[csr] Received signed certificate from the API server:
Issuer: CN=kubernetes | Subject: CN=system:node:yournode | CA: false
Not before: 2016-12-15 19:44:00 +0000 UTC Not After: 2017-12-15 19:44:00 +0000 UTC
[csr] Generating kubelet configuration
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
``` bash
kubeadm join --token <token> <master-ip>
```
Node join complete:
* Certificate signing request sent to master and response
received.
* Kubelet informed of new secure connection details.
The output should look something like:
Run 'kubectl get nodes' on the master to see this machine join.
```
[kubeadm] WARNING: kubeadm is in alpha, please do not use it for production clusters.
[preflight] Running pre-flight checks
[preflight] Starting the kubelet service
[tokens] Validating provided token
[discovery] Created cluster info discovery client, requesting info from "http://192.168.x.y:9898/cluster-info/v1/?token-id=f11877"
[discovery] Cluster info object received, verifying signature using given token
[discovery] Cluster info signature and contents are valid, will use API endpoints [https://192.168.x.y:6443]
[bootstrap] Trying to connect to endpoint https://192.168.x.y:6443
[bootstrap] Detected server version: v1.5.1
[bootstrap] Successfully established connection with endpoint "https://192.168.x.y:6443"
[csr] Created API client to obtain unique certificate for this node, generating keys and certificate signing request
[csr] Received signed certificate from the API server:
Issuer: CN=kubernetes | Subject: CN=system:node:yournode | CA: false
Not before: 2016-12-15 19:44:00 +0000 UTC Not After: 2017-12-15 19:44:00 +0000 UTC
[csr] Generating kubelet configuration
[kubeconfig] Wrote KubeConfig file to disk: "/etc/kubernetes/kubelet.conf"
A few seconds later, you should notice that running `kubectl get nodes` on the master shows a cluster with as many machines as you created.
Node join complete:
* Certificate signing request sent to master and response
received.
* Kubelet informed of new secure connection details.
Run 'kubectl get nodes' on the master to see this machine join.
```
A few seconds later, you should notice that running `kubectl get nodes` on the
master shows a cluster with as many machines as you created.
### (Optional) Controlling your cluster from machines other than the master
In order to get a kubectl on your laptop for example to talk to your cluster, you need to copy the `KubeConfig` file from your master to your laptop like this:
In order to get a kubectl on your laptop for example to talk to your cluster,
you need to copy the `KubeConfig` file from your master to your laptop like
this:
# scp root@<master ip>:/etc/kubernetes/admin.conf .
# kubectl --kubeconfig ./admin.conf get nodes
``` bash
scp root@<master ip>:/etc/kubernetes/admin.conf .
kubectl --kubeconfig ./admin.conf get nodes
```
### (Optional) Connecting to the API Server
If you want to connect to the API Server for viewing the dashboard (note: the dashboard isn't deployed by default) from outside the cluster for example, you can use `kubectl proxy`:
If you want to connect to the API Server for viewing the dashboard (note: the
dashboard isn't deployed by default) from outside the cluster for example, you
can use `kubectl proxy`:
# scp root@<master ip>:/etc/kubernetes/admin.conf .
# kubectl --kubeconfig ./admin.conf proxy
``` bash
scp root@<master ip>:/etc/kubernetes/admin.conf .
kubectl --kubeconfig ./admin.conf proxy
```
You can now access the API Server locally at `http://localhost:8001/api/v1`
### (Optional) Installing a sample application
As an example, install a sample microservices application, a socks shop, to put your cluster through its paces. Note that this demo does only work on `amd64`.
To learn more about the sample microservices app, see the [GitHub README](https://github.com/microservices-demo/microservices-demo).
As an example, install a sample microservices application, a socks shop, to put
your cluster through its paces. Note that this demo does only work on `amd64`.
To learn more about the sample microservices app, see the [GitHub
README](https://github.com/microservices-demo/microservices-demo).
# kubectl create namespace sock-shop
# kubectl apply -n sock-shop -f "https://github.com/microservices-demo/microservices-demo/blob/master/deploy/kubernetes/complete-demo.yaml?raw=true"
``` bash
kubectl create namespace sock-shop
kubectl apply -n sock-shop -f "https://github.com/microservices-demo/microservices-demo/blob/master/deploy/kubernetes/complete-demo.yaml?raw=true"
```
You can then find out the port that the [NodePort feature of services](/docs/user-guide/services/) allocated for the front-end service by running:
You can then find out the port that the [NodePort feature of
services](/docs/user-guide/services/) allocated for the front-end service by
running:
# kubectl describe svc front-end -n sock-shop
Name: front-end
Namespace: sock-shop
Labels: name=front-end
Selector: name=front-end
Type: NodePort
IP: 100.66.88.176
Port: <unset> 80/TCP
NodePort: <unset> 31869/TCP
Endpoints: <none>
Session Affinity: None
``` bash
kubectl describe svc front-end -n sock-shop
```
It takes several minutes to download and start all the containers, watch the output of `kubectl get pods -n sock-shop` to see when they're all up and running.
Output:
Then go to the IP address of your cluster's master node in your browser, and specify the given port.
So for example, `http://<master_ip>:<port>`.
In the example above, this was `30001`, but it is a different port for you.
```
Name: front-end
Namespace: sock-shop
Labels: name=front-end
Selector: name=front-end
Type: NodePort
IP: 100.66.88.176
Port: <unset> 80/TCP
NodePort: <unset> 31869/TCP
Endpoints: <none>
Session Affinity: None
```
If there is a firewall, make sure it exposes this port to the internet before you try to access it.
It takes several minutes to download and start all the containers, watch the
output of `kubectl get pods -n sock-shop` to see when they're all up and
running.
Then go to the IP address of your cluster's master node in your browser, and
specify the given port. So for example, `http://<master_ip>:<port>`. In the
example above, this was `30001`, but it is a different port for you.
If there is a firewall, make sure it exposes this port to the internet before
you try to access it.
## Tear down
* To uninstall the socks shop, run `kubectl delete namespace sock-shop` on the master.
* To uninstall the socks shop, run `kubectl delete namespace sock-shop` on the
master.
* To undo what kubeadm did, simply run:
* To undo what `kubeadm` did, simply run:
``` bash
kubeadm reset
```
# kubeadm reset
If you wish to start over, run `systemctl start kubelet` followed by `kubeadm init` or `kubeadm join`.
If you wish to start over, run `systemctl start kubelet` followed by `kubeadm
init` or `kubeadm join`.
## Explore other add-ons
See the [list of add-ons](/docs/admin/addons/) to explore other add-ons, including tools for logging, monitoring, network policy, visualization &amp; control of your Kubernetes cluster.
See the [list of add-ons](/docs/admin/addons/) to explore other add-ons,
including tools for logging, monitoring, network policy, visualization &amp;
control of your Kubernetes cluster.
## What's next
* Learn about `kubeadm`'s advanced usage on the [advanced reference doc](/docs/admin/kubeadm/)
* Learn more about [Kubernetes concepts and kubectl in Kubernetes 101](/docs/user-guide/walkthrough/).
* Learn about kubeadm's advanced usage on the [advanced reference
doc](/docs/admin/kubeadm/)
* Learn more about [Kubernetes concepts and kubectl in Kubernetes
101](/docs/user-guide/walkthrough/).
## Feedback
* Slack Channel: [#sig-cluster-lifecycle](https://kubernetes.slack.com/messages/sig-cluster-lifecycle/)
* Mailing List: [kubernetes-sig-cluster-lifecycle](https://groups.google.com/forum/#!forum/kubernetes-sig-cluster-lifecycle)
* [GitHub Issues in the kubeadm repository](https://github.com/kubernetes/kubeadm/issues)
* Slack Channel:
[#sig-cluster-lifecycle](https://kubernetes.slack.com/messages/sig-cluster-lifecycle/)
* Mailing List:
[kubernetes-sig-cluster-lifecycle](https://groups.google.com/forum/#!forum/kubernetes-sig-cluster-lifecycle)
* [GitHub Issues in the kubeadm
repository](https://github.com/kubernetes/kubeadm/issues)
## kubeadm is multi-platform
kubeadm deb packages and binaries are built for amd64, arm and arm64, following the [multi-platform proposal](https://github.com/kubernetes/kubernetes/blob/master/docs/proposals/multi-platform.md).
kubeadm deb packages and binaries are built for amd64, arm and arm64, following
the [multi-platform
proposal](https://github.com/kubernetes/kubernetes/blob/master/docs/proposals/multi-platform.md).
deb-packages are released for ARM and ARM 64-bit, but not RPMs (yet, reach out if there's interest).
deb-packages are released for ARM and ARM 64-bit, but not RPMs (yet, reach out
if there's interest).
Currently, only the pod network flannel is working on multiple architectures. You can install it this way:
Currently, only the pod network flannel is working on multiple architectures.
You can install it this way:
# export ARCH=amd64
# curl -sSL "https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml?raw=true" | sed "s/amd64/${ARCH}/g" | kubectl create -f -
``` bash
export ARCH=amd64
curl -sSL "https://github.com/coreos/flannel/blob/master/Documentation/kube-flannel.yml?raw=true" | sed "s/amd64/${ARCH}/g" | kubectl create -f -
```
Replace `ARCH=amd64` with `ARCH=arm` or `ARCH=arm64` depending on the platform you're running on.
Note that the Raspberry Pi 3 is in ARM 32-bit mode, so for RPi 3 you should set `ARCH` to `arm`, not `arm64`.
Replace `ARCH=amd64` with `ARCH=arm` or `ARCH=arm64` depending on the platform
you're running on. Note that the Raspberry Pi 3 is in ARM 32-bit mode, so for
RPi 3 you should set `ARCH` to `arm`, not `arm64`.
## Cloudprovider integrations (experimental)
Enabling specific cloud providers is a common request, this currently requires manual configuration and is therefore not yet supported. If you wish to do so,
edit the `kubeadm` dropin for the `kubelet` service (`/etc/systemd/system/kubelet.service.d/10-kubeadm.conf`) on all nodes, including the master.
If your cloud provider requires any extra packages installed on host, for example for volume mounting/unmounting, install those packages.
Enabling specific cloud providers is a common request, this currently requires
manual configuration and is therefore not yet supported. If you wish to do so,
edit the kubeadm dropin for the kubelet service
(`/etc/systemd/system/kubelet.service.d/10-kubeadm.conf`) on all nodes,
including the master. If your cloud provider requires any extra packages
installed on host, for example for volume mounting/unmounting, install those
packages.
Specify the `--cloud-provider` flag to kubelet and set it to the cloud of your choice. If your cloudprovider requires a configuration
file, create the file `/etc/kubernetes/cloud-config` on every node. The exact format and content of that file depends on the requirements imposed by your cloud provider.
If you use the `/etc/kubernetes/cloud-config` file, you must append it to the `kubelet` arguments as follows:
`--cloud-config=/etc/kubernetes/cloud-config`
Specify the `--cloud-provider` flag to kubelet and set it to the cloud of your
choice. If your cloudprovider requires a configuration file, create the file
`/etc/kubernetes/cloud-config` on every node. The exact format and content of
that file depends on the requirements imposed by your cloud provider. If you use
the `/etc/kubernetes/cloud-config` file, you must append it to the kubelet
arguments as follows: `--cloud-config=/etc/kubernetes/cloud-config`
Lastly, run `kubeadm init --cloud-provider=xxx` to bootstrap your cluster with cloud provider features.
Lastly, run `kubeadm init --cloud-provider=xxx` to bootstrap your cluster with
cloud provider features.
This workflow is not yet fully supported, however we hope to make it extremely easy to spin up clusters with cloud providers in the future.
(See [this proposal](https://github.com/kubernetes/community/pull/128) for more information) The [Kubelet Dynamic Settings](https://github.com/kubernetes/kubernetes/pull/29459) feature may also help to fully automate this process in the future.
This workflow is not yet fully supported, however we hope to make it extremely
easy to spin up clusters with cloud providers in the future. (See [this
proposal](https://github.com/kubernetes/community/pull/128) for more
information) The [Kubelet Dynamic
Settings](https://github.com/kubernetes/kubernetes/pull/29459) feature may also
help to fully automate this process in the future.
## Limitations
Please note: `kubeadm` is a work in progress and these limitations will be addressed in due course.
1. The cluster created here has a single master, with a single `etcd` database running on it.
This means that if the master fails, your cluster loses its configuration data and will need to be recreated from scratch.
Adding HA support (multiple `etcd` servers, multiple API servers, etc) to `kubeadm` is still a work-in-progress.
Please note: kubeadm is a work in progress and these limitations will be
addressed in due course.
Workaround: regularly [back up etcd](https://coreos.com/etcd/docs/latest/admin_guide.html).
The `etcd` data directory configured by `kubeadm` is at `/var/lib/etcd` on the master.
1. The `HostPort` and `HostIP` functionality does not work with kubeadm due to that CNI networking is used, see issue [#31307](https://github.com/kubernetes/kubernetes/issues/31307).
1. The cluster created here has a single master, with a single etcd database
running on it. This means that if the master fails, your cluster loses its
configuration data and will need to be recreated from scratch. Adding HA
support (multiple etcd servers, multiple API servers, etc) to kubeadm is
still a work-in-progress.
Workaround: use the [NodePort feature of services](/docs/user-guide/services/#type-nodeport) instead, or use HostNetwork.
1. Some users on RHEL/CentOS 7 have reported issues with traffic being routed incorrectly due to iptables being bypassed. You should ensure `net.bridge.bridge-nf-call-iptables` is set to 1 in your sysctl config, eg.
Workaround: regularly [back up
etcd](https://coreos.com/etcd/docs/latest/admin_guide.html). The etcd data
directory configured by kubeadm is at `/var/lib/etcd` on the master.
1. The `HostPort` and `HostIP` functionality does not work with kubeadm due to
that CNI networking is used, see issue
[#31307](https://github.com/kubernetes/kubernetes/issues/31307).
```console
# cat /etc/sysctl.d/k8s.conf
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
```
Workaround: use the [NodePort feature of
services](/docs/user-guide/services/#type-nodeport) instead, or use
HostNetwork.
1. Some users on RHEL/CentOS 7 have reported issues with traffic being routed
incorrectly due to iptables being bypassed. You should ensure
`net.bridge.bridge-nf-call-iptables` is set to 1 in your sysctl config, eg.
1. There is no built-in way of fetching the token easily once the cluster is up and running, but here is a `kubectl` command you can copy and paste that will print out the token for you:
``` bash
cat /etc/sysctl.d/k8s.conf
```
```console
# kubectl -n kube-system get secret clusterinfo -o yaml | grep token-map | awk '{print $2}' | base64 --decode | sed "s|{||g;s|}||g;s|:|.|g;s/\"//g;" | xargs echo
```
Should have:
1. If you are using VirtualBox (directly or via Vagrant), you will need to ensure that `hostname -i` returns a routable IP address (i.e. one on the second network interface, not the first one).
By default, it doesn't do this and kubelet ends-up using first non-loopback network interface, which is usually NATed.
Workaround: Modify `/etc/hosts`, take a look at this [`Vagrantfile`][ubuntu-vagrantfile] for how this can be achieved.
```
net.bridge.bridge-nf-call-ip6tables = 1
net.bridge.bridge-nf-call-iptables = 1
```
1. There is no built-in way of fetching the token easily once the cluster is up
and running, but here is a kubectl command you can copy and paste that will
print out the token for you:
``` bash
kubectl -n kube-system get secret clusterinfo -o yaml | \
grep token-map | \
awk '{print $2}' | \
base64 --decode | \
sed "s|{||g;s|}||g;s|:|.|g;s/\"//g;" | \
xargs echo
```
1. If you are using VirtualBox (directly or via Vagrant), you will need to
ensure that `hostname -i` returns a routable IP address (i.e. one on the
second network interface, not the first one). By default, it doesn't do this
and kubelet ends-up using first non-loopback network interface, which is
usually NATed. Workaround: Modify `/etc/hosts`, take a look at this
[`Vagrantfile`][ubuntu-vagrantfile] for how this can be achieved.
[ubuntu-vagrantfile]: https://github.com/errordeveloper/k8s-playground/blob/22dd39dfc06111235620e6c4404a96ae146f26fd/Vagrantfile#L11),