安装Kubernetes K3s系列集群
你可以按照常规方式使用命令curl -sfL https://get.k3s.io | sh -安装K3s，或者你可以使用轻量实用程序k3sup安装（https://github.com/alexellis/k3sup）。具体步骤在之前的文章介绍过。

与我们的设置不同的是，我们使用命令–no-deploy traefik专门安装了不带traefik组件的K3s。

export CLUSTER_MASTER=192.168.3.100
export CLUSTER_DEPLOY_USER=slavko
k3sup install --ip $CLUSTER_MASTER --user $CLUSTER_DEPLOY_USER --k3s-extra-args ‘–no-deploy traefik’
执行后，你将获得使用kubectl所需的连接详细信息。安装K3s后，你可以快速检查是否可以看到节点。

Test your cluster with - export path to k3s cluster kubeconfig:

export KUBECONFIG=/home/slavko/kubeconfig
kubectl get node -o wide
注：这里没有固定的安装模式，你甚至可以使用docker-compose自行启动它。

server:
image: rancher/k3s:v0.8.0
command: server --disable-agent --no-deploy traefik
environment:
- K3S_CLUSTER_SECRET=somethingtotallyrandom
- K3S_KUBECONFIG_OUTPUT=/output/kubeconfig.yaml
- K3S_KUBECONFIG_MODE=666
volumes:
# k3s will generate a kubeconfig.yaml in this directory. This volume is mounted
# on your host, so you can then ‘export KUBECONFIG=/somewhere/on/your/host/out/kubeconfig.yaml’,
# in order for your kubectl commands to work.
- /somewhere/on/your/host/out:/output
# This directory is where you put all the (yaml) configuration files of
# the Kubernetes resources.
- /somewhere/on/your/host/in:/var/lib/rancher/k3s/server/manifests
ports:
- 6443:6443

node:
image: rancher/k3s:v0.8.0
privileged: true
links:
- server
environment:
- K3S_URL=https://server:6443
- K3S_CLUSTER_SECRET=somethingtotallyrandom
volumes:
# this is where you would place a alternative traefik image (saved as a .tar file with
# ‘docker save’), if you want to use it, instead of the traefik:v2.0 image.
- /sowewhere/on/your/host/custom-image:/var/lib/rancher/k3s/agent/images
配置Traefik 2，与Kubernetes一起使用
在文章开头提到的链接中，我已经在我的系统中安装了Traefik 2，并根据该链接内容，服务于一些需求。现在是时候配置Traefik 2 Kubernetes后端了。

Traefik 2使用CRD（自定义资源定义）来完成这一点。定义的最新示例可以在以下链接中找到，但这些示例仅适用于Traefik 2也作为Kubernetes工作负载的一部分执行的情况：

https://docs.traefik.io/reference/dynamic-configuration/kubernetes-crd/

对于外部Traefik 2，我们仅需要以下描述的定义子集。

我们引入一系列自定义资源定义，以允许我们来描述我们的Kubernetes服务将会如何暴露到外部，traefik-crd.yaml：

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: ingressroutes.traefik.containo.us

spec:
group: traefik.containo.us
version: v1alpha1
names:
kind: IngressRoute
plural: ingressroutes
singular: ingressroute
scope: Namespaced

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: ingressroutetcps.traefik.containo.us

spec:
group: traefik.containo.us
version: v1alpha1
names:
kind: IngressRouteTCP
plural: ingressroutetcps
singular: ingressroutetcp
scope: Namespaced

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: middlewares.traefik.containo.us

spec:
group: traefik.containo.us
version: v1alpha1
names:
kind: Middleware
plural: middlewares
singular: middleware
scope: Namespaced

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: tlsoptions.traefik.containo.us

spec:
group: traefik.containo.us
version: v1alpha1
names:
kind: TLSOption
plural: tlsoptions
singular: tlsoption
scope: Namespaced

apiVersion: apiextensions.k8s.io/v1beta1
kind: CustomResourceDefinition
metadata:
name: traefikservices.traefik.containo.us

spec:
group: traefik.containo.us
version: v1alpha1
names:
kind: TraefikService
plural: traefikservices
singular: traefikservice
scope: Namespaced
同时，我们需要集群角色traefik-ingress-controller，以提供对服务、端点和secret的只读访问权限以及自定义的traefik.containo.us组，traefik-clusterrole.yaml：

kind: ClusterRole
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: traefik-ingress-controller

rules:

• apiGroups:
  • “”
    resources:
  • services
  • endpoints
  • secrets
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • extensions
    resources:
  • ingresses
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • extensions
    resources:
  • ingresses/status
    verbs:
  • update
• apiGroups:
  • traefik.containo.us
    resources:
  • middlewares
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • traefik.containo.us
    resources:
  • ingressroutes
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • traefik.containo.us
    resources:
  • ingressroutetcps
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • traefik.containo.us
    resources:
  • tlsoptions
    verbs:
  • get
  • list
  • watch
• apiGroups:
  • traefik.containo.us
    resources:
  • traefikservices
    verbs:
  • get
  • list
  • watch
    最后，我们需要系统服务账号traefik-ingress-controller与之前创建的集群角色traefik-ingress-controller相关联。

kind: ServiceAccount
apiVersion: v1
metadata:
namespace: kube-system
name: traefik-ingress-controller

kind: ClusterRoleBinding
apiVersion: rbac.authorization.k8s.io/v1beta1
metadata:
name: traefik-ingress-controller

roleRef:
apiGroup: rbac.authorization.k8s.io
kind: ClusterRole
name: traefik-ingress-controller
subjects:

• kind: ServiceAccount
  name: traefik-ingress-controller
  namespace: kube-system
  我们应用以上资源之后：

apply:
kubectl apply -f traefik-crd.yaml
kubectl apply -f traefik-clusterrole.yaml
kubectl apply -f traefik-service-account.yaml
我们已经准备好开始调整Traefik 2

将Traefik 2指向K3s集群
根据Traefik文档的建议，当Traefik部署到Kubernetes中时，它将读取环境变量KUBERNETES_SERVICE_HOST和KUBERNETES_SERVICE_PORT或KUBECONFIG来构造端点。

在/var/run/secrets/kubernetes.io/serviceaccount/token中查找访问token，而SSL CA证书将在/var/run/secrets/kubernetes.io/serviceaccount/ca.crt.中查找。当部署到Kubernetes内部时，两者都会自动提供挂载。

当无法找到环境变量时，Traefik会尝试使用external-cluster客户端连接到Kubernetes API server。这一情况下，需要设置endpoint。具体来说，可以将其设置为kubectl代理使用的URL，以使用相关的kubeconfig授予的身份验证和授权连接到Kubernetes集群。

Traefik 2可以使用任何受支持的配置类型来静态配置-toml、yaml或命令行交换。

[providers.kubernetesCRD]
endpoint = “http://localhost:8080”
token = “mytoken”
providers:
kubernetesCRD:
endpoint = “http://localhost:8080”
token = “mytoken”
# …
–providers.kubernetescrd.endpoint=http://localhost:8080
–providers.kubernetescrd.token=mytoken
第一次运行时，如果你在外部有Traefik，很有可能没有traefik-ingress-controller访问token来指定mytoken。那么，你需要执行以下命令：

Check all possible clusters, as your .KUBECONFIG may have multiple contexts:

kubectl config view -o jsonpath=’{“Cluster nametServern”}{range .clusters[*]}{.name}{"t"}{.cluster.server}{"n"}{end}’

Output kind of

Alias tip: k config view -o jsonpath=’{“Cluster nametServern”}{range .clusters[*]}{.name}{"t"}{.cluster.server}{"n"}{end}’

Cluster name Server

default https://127.0.0.1:6443

You are interested in: “default”, if you did not name it differently

Select name of cluster you want to interact with from above output:

export CLUSTER_NAME=“default”

Point to the API server referring the cluster name

export APISERVER=KaTeX parse error: Can't use function '"' in math mode at position 56: …ters[?(@.name==̲"̲CLUSTER_NAME")].cluster.server}")

usually https://127.0.0.1:6443

Gets the token value

export TOKEN=$(kubectl get secrets -o jsonpath="{.items[?(@.metadata.annotations[‘kubernetes.io/service-account.name’]==‘traefik-ingress-controller’)].data.token}" --namespace kube-system|base64 --decode)

Explore the API with TOKEN

如果成功了，你应该收到以下响应：

{
“kind”: “APIVersions”,
“versions”: [
“v1”
],
“serverAddressByClientCIDRs”: [
{
“clientCIDR”: “0.0.0.0/0”,
“serverAddress”: “192.168.3.100:6443”
}
]
以及一些事实，如token：

eyJhbGciOiJSUzI1NiIsImtpZCI6IjBUeTQyNm5nakVWbW5PaTRRbDhucGlPeWhlTHhxTXZjUDJsRmNacURjVnMifQ.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.Mk8EBS4soO8uX-uSnV3o4qZKR6Iw6bgeSmPhHbJ2fjuqFgLnLh4ggxa-N9AqmCsEWiYjSi5oKAu986UEC-_kGQh3xaCYsUwlkM8147fsnwCbomSeGIct14JztVL9F8JwoDH6T0BOEjn-J9uY8-fUKYL_Y7uTrilhFapuILPsj_bFfgIeOOapRD0XshKBQV9Qzg8URxyQyfzl68ilm1Q13h3jLj8CFE2RlgEUFk8TqYH4T4fhfpvV-gNdmKJGODsJDI1hOuWUtBaH_ce9w6woC9K88O3FLKVi7fbvlDFrFoJ2iVZbrRALPjoFN92VA7a6R3pXUbKebTI3aUJiXyfXRQ
根据上次响应的API server的外部地址：https://192.168.3.100:6443

同样，提供的token中没有任何特殊之处：这是JWT的token，你可以使用https://jwt.io/#debugger-io，检查它的内容。

{
“alg”: “RS256”,
“kid”: “0Ty426ngjEVmnOi4Ql8npiOyheLxqMvcP2lFcZqDcVs”
}
{
“iss”: “kubernetes/serviceaccount”,
“kubernetes.io/serviceaccount/namespace”: “kube-system”,
“kubernetes.io/serviceaccount/secret.name”: “traefik-ingress-controller-token-vzc7v”,
“kubernetes.io/serviceaccount/service-account.name”: “traefik-ingress-controller”,
“kubernetes.io/serviceaccount/service-account.uid”: “d9577e91-7e64-4c06-bd82-cde949c81251”,
“sub”: “system:serviceaccount:kube-system:traefik-ingress-controller”
}
正确的配置非常重要，因此请确保对APISERVER的两个调用均返回合理的响应。

export APISERVER=YOURAPISERVER
export TOKEN=YOURTOKEN

curl -X GET $APISERVER/api --header “Authorization: Bearer $TOKEN” --insecure

curl -X GET $APISERVER/api/v1/endpoints --header “Authorization: Bearer $TOKEN” --insecure
创建其他访问token
控制器循环确保每个服务账户都有一个带有API token的secret，可以像我们之前那样被发现。

此外，你还可以为一个服务账户创建额外的token，创建一个ServiceAccountToken类型的secret，并为服务账户添加一个注释，控制器会用生成的token来更新它。

apiVersion: v1
kind: Secret
namespace: kube-system
metadata:
name: traefik-manual-token
annotations:
kubernetes.io/service-account.name: traefik-ingress-controller
type: kubernetes.io/service-account-token

Any tokens for non-existent service accounts will be cleaned up by the token controller.

kubectl describe secrets/traefik-manual-token

用以下命令创建：

kubectl create -f ./traefik-service-account-secret.yaml
kubectl describe secret traefik-manual-token
删除/无效：

kubectl delete secret traefik-manual-token
对外部traefik 2的更改构成定义
我们需要在文章开头给出的链接中获得的traefik2配置进行哪些更改？

https://github.com/Voronenko/traefik2-compose-template

a） 我们在新文件夹kubernetes_data中存储ca.crt文件，该文件用于验证对Kubernetes授权的调用。这是可以在kubeconfig文件的clusters-> cluster-> certificate-authority-data下找到的证书。

该volume将映射在/var/run/secrets/kubernetes.io/serviceaccount下以获取官方Traefik 2镜像

volumes:
…
- ./kubernetes_data:/var/run/secrets/kubernetes.io/serviceaccount
b） 调整Traefik 2 kubernetescrd后端以提供3个参数：endpoint、证书路径和token。请注意，作为外部Traefik作为docker容器，你需要指定正确的endpoint地址，并确保以安全的方式进行。

• “–providers.kubernetescrd=true”
  • “–providers.kubernetescrd.endpoint=https://192.168.3.100:6443”
  • “–providers.kubernetescrd.certauthfilepath=/var/run/secrets/kubernetes.io/serviceaccount/ca.crt”
  • "–providers.kubernetescrd.token=YOURTOKENWITHOUTANYQUOTES
    如果你都执行正确了，那么你现在应该在Traefik UI上看到了一些希望。如果你没有看到traefik，或者在运行Traefik时有问题，你可以查看之后的故障排除部分。

现在是时候通过Trafik 2暴露一些Kubernetes服务了，以确保Traefik 2能够作为ingress工作。让我们来看经典案例whoami服务，whoami-service.yaml

apiVersion: v1
kind: Service
metadata:
name: whoami

spec:
ports:
- protocol: TCP
name: web
port: 80
selector:
app: whoami

kind: Deployment
apiVersion: apps/v1
metadata:
namespace: default
name: whoami
labels:
app: whoami

spec:
replicas: 2
selector:
matchLabels:
app: whoami
template:
metadata:
labels:
app: whoami
spec:
containers:
- name: whoami
image: containous/whoami
ports:
- name: web
containerPort: 80

并且以http或https的方式暴露它，whoami.k.voronenko.net全限定域名下的whoami-ingress-route.yaml。

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: ingressroute-notls
namespace: default
spec:
entryPoints:
- web
routes:
- match: Host(whoami.k.voronenko.net)
kind: Rule
services:
- name: whoami
port: 80

apiVersion: traefik.containo.us/v1alpha1
kind: IngressRoute
metadata:
name: ingressroute-tls
namespace: default
spec:
entryPoints:
- websecure
routes:
- match: Host(whoami.k.voronenko.net)
kind: Rule
services:
- name: whoami
port: 80
tls:
certResolver: default
然后应用它：

kubectl apply -f whoami-service.yaml
kubectl apply -f whoami-ingress-route.yaml
应用后，你应该会在Traefik dashboard上看到一些希望，即KubernetesCRD后端。

正如你所看到的，Traefik已经检测到我们的K3s Kubernetes集群上运行的新工作负载，而且它与我们在同一个盒子上的经典Docker工作负载（如portainer）很好地共存。

让我们检查一下Traefik 2是否将Traefik路由到了我们的Kubernetes工作负载：如你所见，你可以在http和https endpoint上成功地接触到whoami工作负载，浏览器接受你的证书为可信任的“绿标签”。

我们的目标达到了！我们在本地笔记本上配置了Traefik 2。Traefik 2将你的docker或Kubernetes工作流暴露在http或https endpoint上。带可选的 letsencrypt 的 Traefik 2 将负责 https。

故障排查
正如你所知，在配置过程可能存在多个问题，你可以考虑使用一些分析工具，如：

https://github.com/Voronenko/dotfiles/blob/master/Makefile#L185

我特别建议：

a） VMWare octant：这是一个基于Web的功能强大的Kubernetes dashboard，你可以在上面使用你的kubeconfig

b） Rakess：这是一个独立工具也是一个kubectl插件，用于显示Kubernetes服务器资源的访问矩阵（https://github.com/corneliusweig/rakkess）

检查系统账户的凭据

rakkess --sa kube-system:traefik-ingress-controller
c） kubectl

检查哪些角色与服务账户相关联

kubectl get clusterrolebindings -o json | jq -r ’
.items[] |
select(
.subjects // [] | .[] |
[.kind,.namespace,.name] == [“ServiceAccount”,“kube-system”,“traefik-ingress-controller”]
) |
.metadata.name’
d） Traefik 文档：例如kubernetescrd后端提供了更多配置开关的方式。

–providers.kubernetescrd (Default: “false”)
Enable Kubernetes backend with default settings.
–providers.kubernetescrd.certauthfilepath (Default: “”)
Kubernetes certificate authority file path (not needed for in-cluster client).
–providers.kubernetescrd.disablepasshostheaders (Default: “false”)
Kubernetes disable PassHost Headers.
–providers.kubernetescrd.endpoint (Default: “”)
Kubernetes server endpoint (required for external cluster client).
–providers.kubernetescrd.ingressclass (Default: “”)
Value of kubernetes.io/ingress.class annotation to watch for.
–providers.kubernetescrd.labelselector (Default: “”)
Kubernetes label selector to use.
–providers.kubernetescrd.namespaces (Default: “”)
Kubernetes namespaces.
–providers.kubernetescrd.throttleduration (Default: “0”)
Ingress refresh throttle duration
–providers.kubernetescrd.token (Default: “”)
Kubernetes bearer token (not needed for in-cluster client).
–providers.kubernetesingress (Default: “false”)
Enable Kubernetes backend with default settings.
–providers.kubernetesingress.certauthfilepath (Default: “”)
Kubernetes certificate authority file path (not needed for in-cluster client).
–providers.kubernetesingress.disablepasshostheaders (Default: “false”)
Kubernetes disable PassHost Headers.
–providers.kubernetesingress.endpoint (Default: “”)
Kubernetes server endpoint (required for external cluster client).
–providers.kubernetesingress.ingressclass (Default: “”)
Value of kubernetes.io/ingress.class annotation to watch for.
–providers.kubernetesingress.ingressendpoint.hostname (Default: “”)
Hostname used for Kubernetes Ingress endpoints.
–providers.kubernetesingress.ingressendpoint.ip (Default: “”)
IP used for Kubernetes Ingress endpoints.
–providers.kubernetesingress.ingressendpoint.publishedservice (Default: “”)
Published Kubernetes Service to copy status from.
–providers.kubernetesingress.labelselector (Default: “”)
Kubernetes Ingress label selector to use.
–providers.kubernetesingress.namespaces (Default: “”)
Kubernetes namespaces.
–providers.kubernetesingress.throttleduration (Default: “0”)
Ingress refresh throttle duration
–providers.kubernetesingress.token (Default: “”)
Kubernetes bearer token (not needed for in-cluster client).
e） 确保Traefik有足够的权限可以访问apiserver endpoint

如果你希望Traefik为你查询信息：通过在配置中放置一些错误的apiserver地址，可以查看访问的endpoint和查询顺序。有了这些知识和你的Traefik Kubernetes token，你就可以使用Traefik凭证检查这些endpoint是否可以访问。

traefik_1 | E0421 12:30:12.624877 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1.Endpoints: Get https://192.168.3.101:6443/api/v1/endpoints?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625341 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1.Service: Get https://192.168.3.101:6443/api/v1/services?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625395 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1beta1.Ingress: Get https://192.168.3.101:6443/apis/extensions/v1beta1/ingresses?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625449 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1alpha1.Middleware: Get https://192.168.3.101:6443/apis/traefik.containo.us/v1alpha1/middlewares?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625492 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1alpha1.IngressRoute: Get https://192.168.3.101:6443/apis/traefik.containo.us/v1alpha1/ingressroutes?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625531 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1alpha1.TraefikService: Get https://192.168.3.101:6443/apis/traefik.containo.us/v1alpha1/traefikservices?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625572 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1alpha1.TLSOption: Get https://192.168.3.101:6443/apis/traefik.containo.us/v1alpha1/tlsoptions?limit=500&resourceVersion=0:
traefik_1 | E0421 12:30:12.625610 1 reflector.go:125] pkg/mod/k8s.io/client-go@v0.0.0-20190718183610-8e956561bbf5/tools/cache/reflector.go:98: Failed to list *v1alpha1.IngressRouteTCP: Get https://192.168.3.101:6443/apis/traefik.containo.us/v1alpha1/ingressroutetcps?limit=500&resourceVersion=0:
f） 记录K3s本身

安装脚本将自动检测你的操作系统是使用systemd还是openrc并启动服务。使用openrc运行时，将在/var/log/k3s.log中创建日志。使用systemd运行时，将在/var/log/syslog中创建日志，并使用journalctl -u k3s查看。

在那里，你可能会得到一些提示，例如：
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最后

以上就是潇洒冰棍为你收集整理的使用Kubernetes、K3s和Traefik2进行本地开发Test your cluster with - export path to k3s cluster kubeconfig:Check all possible clusters, as your .KUBECONFIG may have multiple contexts:Output kind ofAlias tip: k config view -o jsonpath=’{“Cluster name\tServer\n”}{r的全部内容，希望文章能够帮你解决使用Kubernetes、K3s和Traefik2进行本地开发Test your cluster with - export path to k3s cluster kubeconfig:Check all possible clusters, as your .KUBECONFIG may have multiple contexts:Output kind ofAlias tip: k config view -o jsonpath=’{“Cluster name\tServer\n”}{r所遇到的程序开发问题。

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