导读

Kourier 是一个基于Envoy实现的轻量级网关，是专门对于 Knative Serving 服务访问提供的一个网关实现。

特性

• 提供 Knative revisions 流量分发
• 支持 gRPC 服务.
• 支持超时和重试.
• 支持TLS
• 支持外部认证授权.

Kourier 部署

我们支持两种方式部署使用 Kourier:
• Kourier 社区部署：0.19.0版本
• 阿里云容器服务 Knative 目前也已集成 Kourier 0.19.0 版本, 并且以 addon 组件形式提供支持。在容器服务托管版Kubernetes中， Kourier 已经作为了 Knative 的默认使用网关。

服务访问

这里我们创建一个简单的helloworld的服务进行访问测试。

apiVersion: serving.knative.dev/v1
kind: Service
metadata:
  name: helloworld-go
spec:
  template:
    spec:
      containers:
      - image: registry.cn-hangzhou.aliyuncs.com/knative-sample/helloworld-go:73fbdd56
        env:
        - name: TARGET
          value: "Knative"

执行命令部署：
kubectl apply -f helloworld.yaml

kubectl get ksvc
NAME            URL                                        LATESTCREATED         LATESTREADY           READY   REASON
helloworld-go   http://helloworld-go.default.example.com   helloworld-go-msq9q   helloworld-go-msq9q   True

获取服务访问 IP：

richard@B-N3TEMD6P-1650 kourier % kubectl -n knative-serving get svc kourier
NAME      TYPE           CLUSTER-IP     EXTERNAL-IP      PORT(S)                      AGE
kourier   LoadBalancer   172.21.4.211   47.107.243.210   80:31711/TCP,443:31637/TCP   47h

测试访问：

curl -H "host: helloworld-go.default.example.com"  http://47.107.243.210 -v
*   Trying 47.107.243.210...
* TCP_NODELAY set
* Connected to 47.107.243.210 (47.107.243.210) port 80 (#0)
> GET / HTTP/1.1
> Host: helloworld-go.default.example.com
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK
< content-length: 15
< content-type: text/plain; charset=utf-8
< date: Fri, 15 Jan 2021 09:12:47 GMT
< x-envoy-upstream-service-time: 0
< server: envoy
<
Hello Knative!
* Connection #0 to host 47.107.243.210 left intact
* Closing connection 0

使用证书

Kouier 支持TLS，那么实际如何使用呢？这里也简单介绍一下
创建证书:

openssl genrsa -out tls.key 4096
openssl req -subj "/CN=*.example.com/L=*.example.com" -sha256  -new -key tls.key -out tls.csr
echo subjectAltName = DNS:helloworld-go.default.example.com,DNS:helloworld-go.default.example.cn > extfile.cnf
openssl x509 -req -days 3650 -sha256 -in tls.csr -signkey tls.key -out tls.crt -extfile extfile.cnf

创建secret:

kubectl -n knative-serving create secret tls kourier-cert --key tls.key --cert tls.crt

配置证书:
修改命名空间 knative-serving中的deployment: kourier-control, 配置证书信息:
• CERTS_SECRET_NAMESPACE: 证书 secret 所在的命名空间
• CERTS_SECRET_NAME：证书 secret 名称

kubectl -n knative-serving edit deploy kourier-control
...
   spec:
      containers:
      - env:
        - name: CERTS_SECRET_NAMESPACE
          value: knative-serving
        - name: CERTS_SECRET_NAME
          value: kourier-cert
...

保存上述修改之后, kourier-control会重新启动

kubectl -n knative-serving get po kourier-control-54888647cc-w6gqr
NAME                               READY   STATUS    RESTARTS   AGE
kourier-control-54888647cc-w6gqr   1/1     Running   0          10s

验证服务:
测试访问, 我们这里通过证书访问网关：

curl -H "host: helloworld-go.default.example.com" -k --cert tls.crt --key tls.key https://47.107.243.210 -v
*   Trying 47.107.243.210...
* TCP_NODELAY set
* Connected to 47.107.243.210 (47.107.243.210) port 443 (#0)
* ALPN, offering h2
* ALPN, offering http/1.1
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Server hello (2):
* TLSv1.2 (IN), TLS handshake, Certificate (11):
* TLSv1.2 (IN), TLS handshake, Server key exchange (12):
* TLSv1.2 (IN), TLS handshake, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Change cipher spec (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN, server did not agree to a protocol
* Server certificate:
*  subject: CN=*.example.com; L=*.example.com
*  start date: Jan 15 02:37:00 2021 GMT
*  expire date: Jan 13 02:37:00 2031 GMT
*  issuer: CN=*.example.com; L=*.example.com
*  SSL certificate verify result: self signed certificate (18), continuing anyway.
> GET / HTTP/1.1
> Host: helloworld-go.default.example.com
> User-Agent: curl/7.64.1
> Accept: */*
>
< HTTP/1.1 200 OK