Kubernetes Use Tutorials

xingyuzhe

2020-03-06

Install kubernetes

环境：狗东Ubuntu16

Install and Set Up kubectl

The Kubernetes command-line tool, kubectl, allows you to run commands against Kubernetes clusters. You can use kubectl to deploy applications, inspect and manage cluster resources, and view logs. For a complete list of kubectl operations, see Overview of kubectl.

Before you begin

You must use a kubectl version that is within one minor version difference of your cluster. For example, a v1.2 client should work with v1.1, v1.2, and v1.3 master. Using the latest version of kubectl helps avoid unforeseen issues.

Install kubectl on Linux

Install kubectl binary with curl on Linux

Download the latest release with the command:
```
curl -LO https://storage.googleapis.com/kubernetes-release/release/`curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt`/bin/linux/amd64/kubectl
```
To download a specific version, replace the $(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt) portion of the command with the specific version.
For example, to download version v1.17.0 on Linux, type:
```
curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.17.0/bin/linux/amd64/kubectl
```
Make the kubectl binary executable.
```
chmod +x ./kubectl
```

Move the binary in to your PATH.

sudo mv ./kubectl /usr/local/bin/kubectl

Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```

sudo apt-get update && sudo apt-get install -y apt-transport-https
curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
echo "deb https://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee -a /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update
sudo apt-get install -y kubectl

Install using other package management

Snap
Homebrew

If you are on Ubuntu or another Linux distribution that support snap package manager, kubectl is available as a snap application.

snap install kubectl --classic

kubectl version

Install kubectl on macOS

Install kubectl binary with curl on macOS

Download the latest release:

curl -LO "https://storage.googleapis.com/kubernetes-release/release/$(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt)/bin/darwin/amd64/kubectl"

To download a specific version, replace the $(curl -s https://storage.googleapis.com/kubernetes-release/release/stable.txt) portion of the command with the specific version.

For example, to download version v1.17.0 on macOS, type:

curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.17.0/bin/darwin/amd64/kubectl

Make the kubectl binary executable.
```
chmod +x ./kubectl
```

Move the binary in to your PATH.

sudo mv ./kubectl /usr/local/bin/kubectl

Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```

Install with Homebrew on macOS

If you are on macOS and using Homebrew package manager, you can install kubectl with Homebrew.

Run the installation command:

brew install kubectl

brew install kubernetes-cli

Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```

Install with Macports on macOS

If you are on macOS and using Macports package manager, you can install kubectl with Macports.

Run the installation command:

sudo port selfupdate
sudo port install kubectl

Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```

Install kubectl on Windows

Install kubectl binary with curl on Windows

Download the latest release v1.17.0 from this link.
Or if you have curl installed, use this command:
```
curl -LO https://storage.googleapis.com/kubernetes-release/release/v1.17.0/bin/windows/amd64/kubectl.exe
```
To find out the latest stable version (for example, for scripting), take a look at https://storage.googleapis.com/kubernetes-release/release/stable.txt.
Add the binary in to your PATH.
Test to ensure the version of kubectl is the same as downloaded:
```
kubectl version --client
```

Note: Docker Desktop for Windows adds its own version of kubectl to PATH. If you have installed Docker Desktop before, you may need to place your PATH entry before the one added by the Docker Desktop installer or remove the Docker Desktop’s kubectl.

Install with Powershell from PSGallery

If you are on Windows and using Powershell Gallery package manager, you can install and update kubectl with Powershell.

Run the installation commands (making sure to specify a DownloadLocation):
```
Install-Script -Name install-kubectl -Scope CurrentUser -Force
install-kubectl.ps1 [-DownloadLocation <path>]
```
Note: If you do not specify a DownloadLocation, kubectl will be installed in the user’s temp Directory.
The installer creates $HOME/.kube and instructs it to create a config file
Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```
Note: Updating the installation is performed by rerunning the two commands listed in step 1.

Install on Windows using Chocolatey or Scoop

To install kubectl on Windows you can use either Chocolatey package manager or Scoop command-line installer.

choco
scoop

choco install kubernetes-cli

Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```
Navigate to your home directory:
```
cd %USERPROFILE%
```
Create the .kube directory:
```
mkdir .kube
```
Change to the .kube directory you just created:
```
cd .kube
```
Configure kubectl to use a remote Kubernetes cluster:
```
New-Item config -type file
```
Note: Edit the config file with a text editor of your choice, such as Notepad.

Download as part of the Google Cloud SDK

You can install kubectl as part of the Google Cloud SDK.

Install the Google Cloud SDK.
Run the kubectl installation command:
```
gcloud components install kubectl
```
Test to ensure the version you installed is up-to-date:
```
kubectl version --client
```

Verifying kubectl configuration

In order for kubectl to find and access a Kubernetes cluster, it needs a kubeconfig file, which is created automatically when you create a cluster using kube-up.sh or successfully deploy a Minikube cluster. By default, kubectl configuration is located at ~/.kube/config.

Check that kubectl is properly configured by getting the cluster state:

kubectl cluster-info

If you see a URL response, kubectl is correctly configured to access your cluster.

If you see a message similar to the following, kubectl is not configured correctly or is not able to connect to a Kubernetes cluster.

The connection to the server <server-name:port> was refused - did you specify the right host or port?

For example, if you are intending to run a Kubernetes cluster on your laptop (locally), you will need a tool like Minikube to be installed first and then re-run the commands stated above.

If kubectl cluster-info returns the url response but you can’t access your cluster, to check whether it is configured properly, use:

kubectl cluster-info dump

Optional kubectl configurations

Enabling shell autocompletion

kubectl provides autocompletion support for Bash and Zsh, which can save you a lot of typing.

Below are the procedures to set up autocompletion for Bash (including the difference between Linux and macOS) and Zsh.

Bash on Linux
Bash on macOS
Zsh

Introduction

The kubectl completion script for Bash can be generated with the command kubectl completion bash. Sourcing the completion script in your shell enables kubectl autocompletion.

However, the completion script depends on bash-completion, which means that you have to install this software first (you can test if you have bash-completion already installed by running type _init_completion).

Install bash-completion

bash-completion is provided by many package managers (see here). You can install it with apt-get install bash-completion or yum install bash-completion, etc.

The above commands create /usr/share/bash-completion/bash_completion, which is the main script of bash-completion. Depending on your package manager, you have to manually source this file in your ~/.bashrc file.

To find out, reload your shell and run type _init_completion. If the command succeeds, you’re already set, otherwise add the following to your ~/.bashrc file:

source /usr/share/bash-completion/bash_completion

Reload your shell and verify that bash-completion is correctly installed by typing type _init_completion.

Enable kubectl autocompletion

You now need to ensure that the kubectl completion script gets sourced in all your shell sessions. There are two ways in which you can do this:

Source the completion script in your ~/.bashrc file:

echo ‘source <(kubectl completion bash)‘ >>~/.bashrc

Add the completion script to the /etc/bash_completion.d directory:
```
kubectl completion bash >/etc/bash_completion.d/kubectl
```

If you have an alias for kubectl, you can extend shell completion to work with that alias:

echo ‘alias k=kubectl‘ >>~/.bashrc
echo ‘complete -F __start_kubectl k‘ >>~/.bashrc

Note: bash-completion sources all completion scripts in /etc/bash_completion.d.

Both approaches are equivalent. After reloading your shell, kubectl autocompletion should be working.

Install Minikube

This page shows you how to install Minikube, a tool that runs a single-node Kubernetes cluster in a virtual machine on your personal computer.

To check if virtualization is supported on Linux, run the following command and verify that the output is non-empty:

grep -E --color ‘vmx|svm‘ /proc/cpuinfo

Install kubectl

Make sure you have kubectl installed. You can install kubectl according to the instructions in Install and Set Up kubectl.

Install a Hypervisor

If you do not already have a hypervisor installed, install one of these now:

• KVM, which also uses QEMU

• VirtualBox

Minikube also supports a --vm-driver=none option that runs the Kubernetes components on the host and not in a VM. Using this driver requires Docker and a Linux environment but not a hypervisor.

If you’re using the none driver in Debian or a derivative, use the .deb packages for Docker rather than the snap package, which does not work with Minikube. You can download .deb packages from Docker.

Caution: The none VM driver can result in security and data loss issues. Before using --vm-driver=none, consult this documentation for more information.

Install Minikube using a package

There are experimental packages for Minikube available; you can find Linux (AMD64) packages from Minikube’s releases page on GitHub.

Use your Linux’s distribution’s package tool to install a suitable package.

Install Minikube via direct download

If you’re not installing via a package, you can download a stand-alone binary and use that.

curl -Lo minikube https://storage.googleapis.com/minikube/releases/latest/minikube-linux-amd64 && chmod +x minikube

Here’s an easy way to add the Minikube executable to your path:

sudo mkdir -p /usr/local/bin/
sudo install minikube /usr/local/bin/

Install Minikube using Homebrew

As yet another alternative, you can install Minikube using Linux Homebrew:

brew install minikube

Confirm Installation

To confirm successful installation of both a hypervisor and Minikube, you can run the following command to start up a local Kubernetes cluster:

Note: For setting the --vm-driver with minikube start, enter the name of the hypervisor you installed in lowercase letters where <driver_name> is mentioned below. A full list of --vm-driver values is available in specifying the VM driver documentation.

minikube start --vm-driver=<driver_name>

Once minikube start finishes, run the command below to check the status of the cluster:

minikube status

If your cluster is running, the output from minikube status should be similar to:

host: Running
kubelet: Running
apiserver: Running
kubeconfig: Configured

After you have confirmed whether Minikube is working with your chosen hypervisor, you can continue to use Minikube or you can stop your cluster. To stop your cluster, run:

minikube stop

Clean up local state

If you have previously installed Minikube, and run:

minikube start

and minikube start returned an error:

machine does not exist

then you need to clear minikube’s local state:

minikube delete

kubernetes