add docs for using MultiClusterIngress
Signed-off-by: changzhen <changzhen5@huawei.com>
This commit is contained in:
changzhen
parent
956604dd6e
commit
e99a1ac58f
|
|
@ -0,0 +1,303 @@
|
|||
# Multi-cluster Ingress
|
||||
|
||||
Users can use [MultiClusterIngress API](https://github.com/karmada-io/karmada/blob/master/pkg/apis/networking/v1alpha1/ingress_types.go) provided in Karmada to import external traffic to services in the member clusters.
|
||||
|
||||
## Prerequisites
|
||||
|
||||
### Karmada has been installed
|
||||
|
||||
We can install Karmada by referring to [quick-start](https://github.com/karmada-io/karmada#quick-start), or directly run `hack/local-up-karmada.sh` script which is also used to run our E2E cases.
|
||||
|
||||
### Cluster Network
|
||||
|
||||
Currently, we need to use the [MCS](https://github.com/karmada-io/karmada/blob/master/docs/multi-cluster-service.md#the-serviceexport-and-serviceimport-crds-have-been-installed) feature to import external traffic.
|
||||
|
||||
So we need to ensure that the container networks between the **host cluster** and member clusters are connected. The **host cluster** indicates the cluster where the Karmada control plane is deployed.
|
||||
|
||||
- If you use the `hack/local-up-karmada.sh` script to deploy Karmada, Karmada will have three member clusters, and the container networks between the **host cluster**, `member1` and `member2` are connected.
|
||||
- You can use `Submariner` or other related open source projects to connected networks between clusters.
|
||||
|
||||
## Example
|
||||
|
||||
### Step 1: Deploy ingress-nginx on the host cluster
|
||||
|
||||
We use [multi-cluster-ingress-nginx](https://github.com/karmada-io/multi-cluster-ingress-nginx) as the demo for demonstration. We've made some changes based on the latest version(controller-v1.1.1) of [ingress-nginx](https://github.com/kubernetes/ingress-nginx).
|
||||
|
||||
#### Download code
|
||||
|
||||
```
|
||||
// for HTTPS
|
||||
git clone https://github.com/karmada-io/multi-cluster-ingress-nginx.git
|
||||
// for SSH
|
||||
git clone git@github.com:karmada-io/multi-cluster-ingress-nginx.git
|
||||
```
|
||||
|
||||
#### Build and deploy ingress-nginx
|
||||
|
||||
Using existing `karmada-host` kind cluster to building and deploying the ingress controller.
|
||||
|
||||
```
|
||||
export KIND_CLUSTER_NAME=karmada-host
|
||||
kubectl config use-context karmada-host
|
||||
make dev-env
|
||||
```
|
||||
|
||||
#### Apply kubeconfig secret
|
||||
|
||||
Create a secret that contains the `karmada-apiserver` authentication credential in the following format:
|
||||
|
||||
```yaml
|
||||
# karmada-kubeconfig-secret.yaml
|
||||
apiVersion: v1
|
||||
data:
|
||||
kubeconfig: {data} # encoded by base64
|
||||
kind: Secret
|
||||
metadata:
|
||||
name: kubeconfig
|
||||
namespace: ingress-nginx
|
||||
type: Opaque
|
||||
```
|
||||
|
||||
You can get the authentication credential from the `/root/.kube/karmada.config` file, or use command:
|
||||
|
||||
```
|
||||
kubectl -n karmada-system get secret kubeconfig -oyaml | grep kubeconfig | sed -n '1p' | awk '{print $2}'
|
||||
```
|
||||
|
||||
Then apply yaml:
|
||||
|
||||
```
|
||||
kubectl apply -f karmada-kubeconfig-secret.yaml
|
||||
```
|
||||
|
||||
#### Edit ingress-nginx-controller deployment
|
||||
|
||||
We want `nginx-ingress-controller` to access `karmada-apiserver` to listen to resource(such as multiclusteringress, endpointslices, service, etc.) changes, therefore, we need to mount the authentication credential of `karmada-apiserver` to the `nginx-ingress-controller`.
|
||||
|
||||
```
|
||||
kubectl -n ingress-nginx edit deployment ingress-nginx-controller
|
||||
```
|
||||
|
||||
Edit as follows:
|
||||
|
||||
```yaml
|
||||
apiVersion: apps/v1
|
||||
kind: Deployment
|
||||
metadata:
|
||||
...
|
||||
spec:
|
||||
...
|
||||
template:
|
||||
spec:
|
||||
containers:
|
||||
- args:
|
||||
- /nginx-ingress-controller
|
||||
- --karmada-kubeconfig=/etc/kubeconfig # new line
|
||||
...
|
||||
volumeMounts:
|
||||
...
|
||||
- mountPath: /etc/kubeconfig # new line
|
||||
name: kubeconfig # new line
|
||||
subPath: kubeconfig # new line
|
||||
volumes:
|
||||
...
|
||||
- name: kubeconfig # new line
|
||||
secret: # new line
|
||||
secretName: kubeconfig # new line
|
||||
```
|
||||
|
||||
### Step 2: Use MCS feature to discovery service
|
||||
|
||||
#### Install ServiceExport and ServiceImport CRDs
|
||||
|
||||
Refer to [here](https://github.com/karmada-io/karmada/blob/master/docs/multi-cluster-service.md#the-serviceexport-and-serviceimport-crds-have-been-installed).
|
||||
|
||||
#### Deploy web on member1 cluster
|
||||
|
||||
deploy.yaml:
|
||||
|
||||
<details>
|
||||
|
||||
<summary>unfold me to see the yaml</summary>
|
||||
|
||||
```yaml
|
||||
kind: Deployment
|
||||
metadata:
|
||||
name: web
|
||||
spec:
|
||||
replicas: 1
|
||||
selector:
|
||||
matchLabels:
|
||||
app: web
|
||||
template:
|
||||
metadata:
|
||||
labels:
|
||||
app: web
|
||||
spec:
|
||||
containers:
|
||||
- name: hello-app
|
||||
image: gcr.io/google-samples/hello-app:1.0
|
||||
ports:
|
||||
- containerPort: 8080
|
||||
protocol: TCP
|
||||
---
|
||||
apiVersion: v1
|
||||
kind: Service
|
||||
metadata:
|
||||
name: web
|
||||
spec:
|
||||
ports:
|
||||
- port: 81
|
||||
targetPort: 8080
|
||||
selector:
|
||||
app: web
|
||||
---
|
||||
apiVersion: policy.karmada.io/v1alpha1
|
||||
kind: PropagationPolicy
|
||||
metadata:
|
||||
name: mcs-workload
|
||||
spec:
|
||||
resourceSelectors:
|
||||
- apiVersion: apps/v1
|
||||
kind: Deployment
|
||||
name: web
|
||||
- apiVersion: v1
|
||||
kind: Service
|
||||
name: web
|
||||
placement:
|
||||
clusterAffinity:
|
||||
clusterNames:
|
||||
- member1
|
||||
```
|
||||
|
||||
</details>
|
||||
|
||||
```
|
||||
kubectl --context karmada-apiserver apply -f deploy.yaml
|
||||
```
|
||||
|
||||
#### Export web service from member1 cluster
|
||||
|
||||
service_export.yaml:
|
||||
|
||||
<details>
|
||||
|
||||
<summary>unfold me to see the yaml</summary>
|
||||
|
||||
```yaml
|
||||
apiVersion: multicluster.x-k8s.io/v1alpha1
|
||||
kind: ServiceExport
|
||||
metadata:
|
||||
name: web
|
||||
---
|
||||
apiVersion: policy.karmada.io/v1alpha1
|
||||
kind: PropagationPolicy
|
||||
metadata:
|
||||
name: web-export-policy
|
||||
spec:
|
||||
resourceSelectors:
|
||||
- apiVersion: multicluster.x-k8s.io/v1alpha1
|
||||
kind: ServiceExport
|
||||
name: web
|
||||
placement:
|
||||
clusterAffinity:
|
||||
clusterNames:
|
||||
- member1
|
||||
```
|
||||
|
||||
</details>
|
||||
|
||||
```
|
||||
kubectl --context karmada-apiserver apply -f service_export.yaml
|
||||
```
|
||||
|
||||
#### Import web service to member2 cluster
|
||||
|
||||
service_import.yaml:
|
||||
|
||||
<details>
|
||||
|
||||
<summary>unfold me to see the yaml</summary>
|
||||
|
||||
```yaml
|
||||
apiVersion: multicluster.x-k8s.io/v1alpha1
|
||||
kind: ServiceImport
|
||||
metadata:
|
||||
name: web
|
||||
spec:
|
||||
type: ClusterSetIP
|
||||
ports:
|
||||
- port: 81
|
||||
protocol: TCP
|
||||
---
|
||||
apiVersion: policy.karmada.io/v1alpha1
|
||||
kind: PropagationPolicy
|
||||
metadata:
|
||||
name: web-import-policy
|
||||
spec:
|
||||
resourceSelectors:
|
||||
- apiVersion: multicluster.x-k8s.io/v1alpha1
|
||||
kind: ServiceImport
|
||||
name: web
|
||||
placement:
|
||||
clusterAffinity:
|
||||
clusterNames:
|
||||
- member2
|
||||
```
|
||||
|
||||
</details>
|
||||
|
||||
```
|
||||
kubectl --context karmada-apiserver apply -f service_import.yaml
|
||||
```
|
||||
|
||||
### Step 3: Deploy multiclusteringress on karmada-controlplane
|
||||
|
||||
mci-web.yaml:
|
||||
|
||||
<details>
|
||||
|
||||
<summary>unfold me to see the yaml</summary>
|
||||
|
||||
```yaml
|
||||
apiVersion: networking.karmada.io/v1alpha1
|
||||
kind: MultiClusterIngress
|
||||
metadata:
|
||||
name: demo-localhost
|
||||
namespace: default
|
||||
spec:
|
||||
ingressClassName: nginx
|
||||
rules:
|
||||
- host: demo.localdev.me
|
||||
http:
|
||||
paths:
|
||||
- backend:
|
||||
service:
|
||||
name: web
|
||||
port:
|
||||
number: 81
|
||||
path: /web
|
||||
pathType: Prefix
|
||||
```
|
||||
|
||||
</details>
|
||||
|
||||
```
|
||||
kubectl --context karmada-apiserver apply -f
|
||||
```
|
||||
|
||||
### Step 4: Local testing
|
||||
|
||||
Let's forward a local port to the ingress controller:
|
||||
|
||||
```
|
||||
kubectl port-forward --namespace=ingress-nginx service/ingress-nginx-controller 8080:80
|
||||
```
|
||||
|
||||
At this point, if you access http://demo.localdev.me:8080/web/, you should see an HTML page telling you:
|
||||
|
||||
```html
|
||||
Hello, world!
|
||||
Version: 1.0.0
|
||||
Hostname: web-xxx-xxx
|
||||
```
|
||||
Loading…
Reference in New Issue