Kubernetes
最近在准备 CKA 考试,所以需要搭建一个 Kubernetes 集群来方便练习.GCP 平台新用户注册送 300 刀体验金,所以就想到用 kubeadm 在 GCP 弄个练练手,既方便又省钱.
这一套做下来,还是比较容易上手的,kubeadm 提供的是傻瓜式的安装体验,所以难度主要还是在访问外国网站和熟悉 GCP 的命令上,接下来就详细记述一下如何操作.
接下来的操作都假设已经设置好了访问外国网站,由于政策原因,具体做法请自行搜索;而且已经注册好了 GCP 账户,链接如下:GCP
首先需要在本地电脑上安装 GCP 命令行客户端:gcloud,参考链接为:gcloud
因为众所周知的原因,gcloud 要能正常使用,要设置代理才可以,下面是设置 SOCKS5 代理的命令:
# gcloud config set proxy/type PROXY_TYPE
$ gcloud config set proxy/type socks5
# gcloud config set proxy/address PROXY_IP_ADDRESS
$ gcloud config set proxy/address 127.0.0.1
# gcloud config set proxy/port PROXY_PORT
$ gcloud config set proxy/address 1080
如果是第一次使用 GCP,需要先进行初始化.在初始化的过程中会有几次交互,使用默认选项即可.由于之前已经设置了代理,网络代理相关部分就可以跳过了. 注意:在选择 region(区域)时,建议选择 us-west2,原因是目前大部分 GCP 的 region,体验用户只能最多创建四个虚拟机实例,只有少数几个区域可以创建六个,其中就包括 us-west2,正常来讲,搭建 Kubernetes 需要三个 master,三个 worker,四个不太够用,当然如果只是试试的话,两个节点,一主一从,也够用了.
$ gcloud init
Welcome! This command will take you through the configuration of gcloud.
Settings from your current configuration [profile-name] are:
core:
disable_usage_reporting: 'True'
Pick configuration to use:
[1] Re-initialize this configuration [profile-name] with new settings
[2] Create a new configuration
[3] Switch to and re-initialize existing configuration: [default]
Please enter your numeric choice: 3
Your current configuration has been set to: [default]
You can skip diagnostics next time by using the following flag:
gcloud init --skip-diagnostics
Network diagnostic detects and fixes local network connection issues.
Checking network connection...done.
ERROR: Reachability Check failed.
Cannot reach https://www.google.com (ServerNotFoundError)
Cannot reach https://accounts.google.com (ServerNotFoundError)
Cannot reach https://cloudresourcemanager.googleapis.com/v1beta1/projects (ServerNotFoundError)
Cannot reach https://www.googleapis.com/auth/cloud-platform (ServerNotFoundError)
Cannot reach https://dl.google.com/dl/cloudsdk/channels/rapid/components-2.json (ServerNotFoundError)
Network connection problems may be due to proxy or firewall settings.
Current effective Cloud SDK network proxy settings:
type = socks5
host = PROXY_IP_ADDRESS
port = 1080
username = None
password = None
What would you like to do?
[1] Change Cloud SDK network proxy properties
[2] Clear all gcloud proxy properties
[3] Exit
Please enter your numeric choice: 1
Select the proxy type:
[1] HTTP
[2] HTTP_NO_TUNNEL
[3] SOCKS4
[4] SOCKS5
Please enter your numeric choice: 4
Enter the proxy host address: 127.0.0.1
Enter the proxy port: 1080
Is your proxy authenticated (y/N)? N
Cloud SDK proxy properties set.
Rechecking network connection...done.
Reachability Check now passes.
Network diagnostic (1/1 checks) passed.
You must log in to continue. Would you like to log in (Y/n)? y
Your browser has been opened to visit:
https://accounts.google.com/o/oauth2/auth?redirect_uri=......
已在现有的浏览器会话中创建新的窗口。
Updates are available for some Cloud SDK components. To install them,
please run:
$ gcloud components update
You are logged in as: [<gmail account>].
Pick cloud project to use:
[1] <project-id>
[2] Create a new project
Please enter numeric choice or text value (must exactly match list
item): 1
Your current project has been set to: [<project-id>].
Your project default Compute Engine zone has been set to [us-west2-b].
You can change it by running [gcloud config set compute/zone NAME].
Your project default Compute Engine region has been set to [us-west2].
You can change it by running [gcloud config set compute/region NAME].
Created a default .boto configuration file at [/home/<username>/.boto]. See this file and
[https://cloud.google.com/storage/docs/gsutil/commands/config] for more
information about configuring Google Cloud Storage.
Your Google Cloud SDK is configured and ready to use!
* Commands that require authentication will use <gmail account> by default
* Commands will reference project `<project-id>` by default
* Compute Engine commands will use region `us-west2` by default
* Compute Engine commands will use zone `us-west2-b` by default
Run `gcloud help config` to learn how to change individual settings
This gcloud configuration is called [default]. You can create additional configurations if you work with multiple accounts and/or projects.
Run `gcloud topic configurations` to learn more.
Some things to try next:
* Run `gcloud --help` to see the Cloud Platform services you can interact with. And run `gcloud help COMMAND` to get help on any gcloud command.
* Run `gcloud topic -h` to learn about advanced features of the SDK like arg files and output formatting
接下来创建 Kuernetes 所需的 GCP 资源.
第一步是创建网络和子网.
$ gcloud compute networks create cka --subnet-mode custom
$ gcloud compute networks subnets create kubernetes --network cka --range 10.240.0.0/24
接下来要创建防火墙规则,配置哪些端口是可以开放访问的.一共两条规则,一个外网,一个内网. 外网规则只需要开放 ssh, ping 和 kube-api 的访问就足够了:
$ gcloud compute firewall-rules create cka-external --allow tcp:22,tcp:6443,icmp --network cka --source-ranges 0.0.0.0/0
内网规则设置好 GCP 虚拟机网段和后面 pod 的网段可以互相访问即可,因为后面会使用 calico 作为网络插件,所以只开放 TCP, UDP 和 ICMP 是不够的,还需要开放 BGP,但 GCP 的防火墙规则中没哟 BGP 选项,所以放开全部协议的互通.
$ gcloud compute firewall-rules create cka-internal --network cka --allow=all --source-ranges 192.168.0.0/16,10.240.0.0/16
最后创建 GCP 虚拟机实例.
$ gcloud compute instances create controller-1 --async --boot-disk-size 200GB --can-ip-forward --image-family ubuntu-1804-lts --image-project ubuntu-os-cloud --machine-type n1-standard-1 --private-network-ip 10.240.0.11 --scopes compute-rw,storage-ro,service-management,service-control,logging-write,monitoring --subnet kubernetes --tags cka,controller
$ gcloud compute instances create worker-1 --async --boot-disk-size 200GB --can-ip-forward --image-family ubuntu-1804-lts --image-project ubuntu-os-cloud --machine-type n1-standard-1 --private-network-ip 10.240.0.21 --scopes compute-rw,storage-ro,service-management,service-control,logging-write,monitoring --subnet kubernetes --tags cka,worker
使用 gcloud 登录 controller-1
$ gcloud compute ssh controller-1
WARNING: The public SSH key file for gcloud does not exist.
WARNING: The private SSH key file for gcloud does not exist.
WARNING: You do not have an SSH key for gcloud.
WARNING: SSH keygen will be executed to generate a key.
Generating public/private rsa key pair.
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/<username>/.ssh/google_compute_engine.
Your public key has been saved in /home/<username>/.ssh/google_compute_engine.pub.
The key fingerprint is:
SHA256:jpaZtzz42t7FjB1JV06GeVHhXVi12LF/a+lfl7TK2pw <username>@<username>
The key's randomart image is:
+---[RSA 2048]----+
| O&|
| B=B|
| ...*o|
| . o .|
| S o .o|
| * = .. *|
| *.o . = *o|
| ..+.o .+ = o|
| .+*....E .o|
+----[SHA256]-----+
Updating project ssh metadata...⠧Updated [https://www.googleapis.com/compute/v1/projects/<project-id>].
Updating project ssh metadata...done.
Waiting for SSH key to propagate.
Warning: Permanently added 'compute.2329485573714771968' (ECDSA) to the list of known hosts.
Welcome to Ubuntu 18.04.1 LTS (GNU/Linux 4.15.0-1025-gcp x86_64)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
* Support: https://ubuntu.com/advantage
System information as of Wed Dec 5 03:05:31 UTC 2018
System load: 0.0 Processes: 87
Usage of /: 1.2% of 96.75GB Users logged in: 0
Memory usage: 5% IP address for ens4: 10.240.0.11
Swap usage: 0%
Get cloud support with Ubuntu Advantage Cloud Guest:
http://www.ubuntu.com/business/services/cloud
0 packages can be updated.
0 updates are security updates.
$ ssh -l<user-name> -i .ssh/google_compute_engine.pub 35.236.126.174
安装 kubeadm, docker, kubelet, kubectl.
$ sudo apt update
$ sudo apt upgrade -y
$ sudo apt-get install -y docker.io
$ sudo vim /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
$ curl -s https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo apt-key add -
OK
$ sudo apt update
$ sudo apt-get install -y \
kubeadm=1.12.2-00 kubelet=1.12.2-00 kubectl=1.12.2-00
kubeadm 初始化
$ sudo kubeadm init --pod-network-cidr 192.168.0.0/16
配置 calico 网络插件
$ wget https://tinyurl.com/yb4xturm \
-O rbac-kdd.yaml
$ wget https://tinyurl.com/y8lvqc9g \
-O calico.yaml
$ kubectl apply -f rbac-kdd.yaml
$ kubectl apply -f calico.yaml
配置 kubectl 的 bash 自动补全.
$ source <(kubectl completion bash)
$ echo "source <(kubectl completion bash)" >> ~/.bashrc
这里偷懒了一下,从节点安装的包和主节点一模一样,大家可以根据需求,去掉一些不必要的包.
$ sudo apt-get update && sudo apt-get upgrade -y
$ apt-get install -y docker.io
$ sudo vim /etc/apt/sources.list.d/kubernetes.list
deb http://apt.kubernetes.io/ kubernetes-xenial main
$ curl -s \
https://packages.cloud.google.com/apt/doc/apt-key.gpg \
| sudo apt-key add -
$ sudo apt-get update
$ sudo apt-get install -y \
kubeadm=1.12.2-00 kubelet=1.12.2-00 kubectl=1.12.2-00
如果此时 kubeadm init 命令中的 join 命令找不到了,或者 bootstrap token 过期了,该怎么办呢,下面就是解决方法.
$ sudo kubeadm token list
TOKEN TTL EXPIRES USAGES DESCRIPTION
27eee4.6e66ff60318da929 23h 2017-11-03T13:27:33Z
authentication,signing The default bootstrap token generated
by ’kubeadm init’....
$ sudo kubeadm token create
27eee4.6e66ff60318da929
$ openssl x509 -pubkey \
-in /etc/kubernetes/pki/ca.crt | openssl rsa \
-pubin -outform der 2>/dev/null | openssl dgst \
-sha256 -hex | sed ’s/^.* //’
6d541678b05652e1fa5d43908e75e67376e994c3483d6683f2a18673e5d2a1b0
最后执行 kubeadm join 命令.
$ sudo kubeadm join \
--token 27eee4.6e66ff60318da929 \
10.128.0.3:6443 \
--discovery-token-ca-cert-hash \
sha256:6d541678b05652e1fa5d43908e75e67376e994c3483d6683f2a18673e5d2a1b0