Knative第一部分-Knative Serving部署与测试
目录
Knative部署与测试
1. Knative简介
knative 是谷歌牵头的 serverless 架构方案，旨在提供一套简单易用的 serverless 开源方案，把 serverless 标准化和平台化。目前参与 knative 项目的公司主要有： Google、Pivotal、IBM、Red Hat和SAP。
早期版本有以下Knative组件：
- Build - 源到容器的构建编排
- Eventing - 管理和交付事件
- Serving - 请求驱动的计算，可以扩展到零
因某些原因，2019年Build组年已经发展成一个独立项目Tekton，所以Knative现在主要由两个部分组成，Knative Serving以及Knative Eventing.
2. 安装前准备
本次安装的Knative为最新的0.24版本，部署要求为：
- Kubernetes v1.18或以上版本，我们这次是基于Kubernetes v1.19版本进行测试
- Kubernetes集群每节点最低有2 CPUs, 4 GB内存, 20 GB以上的磁盘空间
- 选择一种Knative的网络层，可选的有Kourier,Ambassador,Contour,Istio，我们使用Istio来进行测试
3. 安装Knative Serving
3.1 部署Knative Serving
通过下面的操作，我们可以先安装Knative Serving:
wget https://github.com/knative/serving/releases/download/v0.24.0/serving-crds.yaml
wget https://github.com/knative/serving/releases/download/v0.24.0/serving-core.yaml
kubectl apply -f ./serving-crds.yaml
kubectl apply -f ./serving-core.yaml
查看各个资源是否已经正常：
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get all -n knative-serving
NAME READY STATUS RESTARTS AGE
pod/activator-dfc4f7578-265fn 0/1 ImagePullBackOff 0 15h
pod/autoscaler-756797655b-nc8ln 0/1 ImagePullBackOff 0 15h
pod/controller-7bccdf6fdb-6tznw 0/1 ImagePullBackOff 0 15h
pod/domain-mapping-65fd554865-9zv4t 0/1 ImagePullBackOff 0 15h
pod/domainmapping-webhook-7ff8f59965-p9hvc 0/1 ImagePullBackOff 0 15h
pod/webhook-568c4d697-xvrhc 0/1 ImagePullBackOff 0 15h
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/activator-service ClusterIP 10.248.231.247 <none> 9090/TCP,8008/TCP,80/TCP,81/TCP 15h
service/autoscaler ClusterIP 10.248.128.26 <none> 9090/TCP,8008/TCP,8080/TCP 15h
service/controller ClusterIP 10.248.129.16 <none> 9090/TCP,8008/TCP 15h
service/domainmapping-webhook ClusterIP 10.248.155.59 <none> 9090/TCP,8008/TCP,443/TCP 15h
service/webhook ClusterIP 10.248.172.13 <none> 9090/TCP,8008/TCP,443/TCP 15h
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/activator 0/1 1 0 15h
deployment.apps/autoscaler 0/1 1 0 15h
deployment.apps/controller 0/1 1 0 15h
deployment.apps/domain-mapping 0/1 1 0 15h
deployment.apps/domainmapping-webhook 0/1 1 0 15h
deployment.apps/webhook 0/1 1 0 15h
NAME DESIRED CURRENT READY AGE
replicaset.apps/activator-dfc4f7578 1 1 0 15h
replicaset.apps/autoscaler-756797655b 1 1 0 15h
replicaset.apps/controller-7bccdf6fdb 1 1 0 15h
replicaset.apps/domain-mapping-65fd554865 1 1 0 15h
replicaset.apps/domainmapping-webhook-7ff8f59965 1 1 0 15h
replicaset.apps/webhook-568c4d697 1 1 0 15h
NAME REFERENCE TARGETS MINPODS MAXPODS REPLICAS AGE
horizontalpodautoscaler.autoscaling/activator Deployment/activator <unknown>/100% 1 20 1 15h
horizontalpodautoscaler.autoscaling/webhook Deployment/webhook <unknown>/100% 1 5 1 15h
我们可以发现，POD没有起来，原因为ImagePullBackOff。主要是国内拉不到海外镜像的原因，下面的命令通过更换国内加速镜像地址解决：
[root@sh-saas-k8stest-master-dev-01 knative]# sed -i 's/gcr.io/gcr.tencentcloudcr.com/g' serving-core.yaml
[root@sh-saas-k8stest-master-dev-01 knative]# grep "gcr.tencentcloudcr.com" serving-core.yaml
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/queue@sha256:6c6fdac40d3ea53e39ddd6bb00aed8788e69e7fac99e19c98ed911dd1d2f946b
queueSidecarImage: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/queue@sha256:6c6fdac40d3ea53e39ddd6bb00aed8788e69e7fac99e19c98ed911dd1d2f946b
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/activator@sha256:bd48057f8d6e5f95f389225979c89d2d99d52a4876d2342fc033c909096d4698
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/autoscaler@sha256:d3d6f5ecfff577a6d4d5a0549379fa1acf1d66d7422a58b1756e40eba555285c
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/controller@sha256:e9b9cc7a2a091194161a7a256d6fc342317080f1a31e1f1a33993a5e1993fdb5
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/domain-mapping@sha256:fafa1afcc9f2c6e79b096ffbc67e14ff3f34e3591d887335811ca15970b3b837
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/domain-mapping-webhook@sha256:1335e57427a372d15e8a90a3370eaa6896c9cb3fd7cb6f2a63021cceaea2e8e6
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/serving/cmd/webhook@sha256:e9503135b4b46a3700d91bdb32df60923575aaedbcc5192bdc3e41b64591ee50
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl apply -f ./serving-core.yaml
现在查看POD状态，都正常了：
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get pod -n knative-serving
NAME READY STATUS RESTARTS AGE
activator-bbb849d6-ch9lq 1/1 Running 0 28s
autoscaler-6fcf6994dd-ts26g 1/1 Running 0 28s
controller-7b586546c8-4rtfq 1/1 Running 0 28s
domain-mapping-c464c4dfc-2w4zg 1/1 Running 0 27s
domainmapping-webhook-6f947f9f89-dn4kv 1/1 Running 0 27s
webhook-7945667f7-kfv58 1/1 Running 0 26s
如果没有部署istio,需先部署istio，我这边已经部署好istio 1.10.3，就跳过这步了。
3.2 部署Knative Istio controller
[root@sh-saas-k8stest-master-dev-01 knative]# wget https://github.com/knative/net-istio/releases/download/v0.24.0/net-istio.yaml
[root@sh-saas-k8stest-master-dev-01 knative]# sed -i 's/gcr.io/gcr.tencentcloudcr.com/g' net-istio.yaml
[root@sh-saas-k8stest-master-dev-01 knative]# grep "gcr.tencentcloudcr.com" net-istio.yaml
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/net-istio/cmd/controller@sha256:41f58d7e8319e473dbf27dec3d329b631f03ec0899c98ba2dd3d3166a6fb7a42
image: gcr.tencentcloudcr.com/knative-releases/knative.dev/net-istio/cmd/webhook@sha256:49bf045db42aa0bfe124e9c5a5c511595e8fc27bf3a77e3900d9dec2b350173c
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl apply -f net-istio.yaml
clusterrole.rbac.authorization.k8s.io/knative-serving-istio created
gateway.networking.istio.io/knative-ingress-gateway created
gateway.networking.istio.io/knative-local-gateway created
service/knative-local-gateway created
configmap/config-istio created
peerauthentication.security.istio.io/webhook created
peerauthentication.security.istio.io/domainmapping-webhook created
peerauthentication.security.istio.io/net-istio-webhook created
deployment.apps/net-istio-controller created
deployment.apps/net-istio-webhook created
secret/net-istio-webhook-certs created
service/net-istio-webhook created
mutatingwebhookconfiguration.admissionregistration.k8s.io/webhook.istio.networking.internal.knative.dev created
validatingwebhookconfiguration.admissionregistration.k8s.io/config.webhook.istio.networking.internal.knative.dev created
[root@sh-saas-k8stest-master-dev-01 knative]#
4. 测试Knative Serving
编写一个helloworld-go.yaml：
apiVersion: serving.knative.dev/v1
kind: Service
metadata:
name: helloworld-go
namespace: example
spec:
template:
spec:
containers:
- image: registry.cn-hangzhou.aliyuncs.com/knative-sample/helloworld-go:160e4dc8
env:
- name: TARGET
value: "Go Sample v1"
创建上面的Kn Service:
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl create namespace example
namespace/example created
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl apply -f helloworld-go.yaml
service.serving.knative.dev/helloworld-go created
查看Knative Serving创建的相关资源：
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get all -n example
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/helloworld-go ExternalName <none> knative-local-gateway.istio-system.svc.cluster.local 80/TCP 2m2s
service/helloworld-go-00001 ClusterIP 10.248.140.210 <none> 80/TCP 2m13s
service/helloworld-go-00001-private ClusterIP 10.248.227.128 <none> 80/TCP,9090/TCP,9091/TCP,8022/TCP,8012/TCP 2m13s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/helloworld-go-00001-deployment 0/0 0 0 2m13s
NAME DESIRED CURRENT READY AGE
replicaset.apps/helloworld-go-00001-deployment-7754b949cb 0 0 0 2m13s
NAME URL READY REASON
route.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com True
NAME URL LATESTCREATED LATESTREADY READY REASON
service.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com helloworld-go-00001 helloworld-go-00001 True
NAME CONFIG NAME K8S SERVICE NAME GENERATION READY REASON ACTUAL REPLICAS DESIRED REPLICAS
revision.serving.knative.dev/helloworld-go-00001 helloworld-go helloworld-go-00001 1 True 0 0
NAME LATESTCREATED LATESTREADY READY REASON
configuration.serving.knative.dev/helloworld-go helloworld-go-00001 helloworld-go-00001 True
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get svc istio-ingressgateway --namespace istio-system
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
istio-ingressgateway NodePort 10.248.132.176 <none> 80:20080/TCP,443:20443/TCP,15020:37042/TCP,15029:31676/TCP,15030:26910/TCP,15031:30084/TCP,15032:30347/TCP,15443:27715/TCP,31400:25312/TCP 4d7h
访问一下，可以看到第一次访问时间花了1.45秒，原因是流量来了，自动扩容新起来了一个POD：
[root@sh-saas-k8stest-master-dev-01 knative]# time curl -H "Host: helloworld-go.example.example.com" http://10.248.132.176
Hello Go Sample v1!
real 0m1.457s
user 0m0.001s
sys 0m0.003s
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get all -n example
NAME READY STATUS RESTARTS AGE
pod/helloworld-go-00001-deployment-7754b949cb-4zsl5 2/2 Running 0 7s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/helloworld-go ExternalName <none> knative-local-gateway.istio-system.svc.cluster.local 80/TCP 11m
service/helloworld-go-00001 ClusterIP 10.248.140.210 <none> 80/TCP 12m
service/helloworld-go-00001-private ClusterIP 10.248.227.128 <none> 80/TCP,9090/TCP,9091/TCP,8022/TCP,8012/TCP 12m
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/helloworld-go-00001-deployment 1/1 1 1 12m
NAME DESIRED CURRENT READY AGE
replicaset.apps/helloworld-go-00001-deployment-7754b949cb 1 1 1 12m
NAME URL LATESTCREATED LATESTREADY READY REASON
service.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com helloworld-go-00001 helloworld-go-00001 True
NAME CONFIG NAME K8S SERVICE NAME GENERATION READY REASON ACTUAL REPLICAS DESIRED REPLICAS
revision.serving.knative.dev/helloworld-go-00001 helloworld-go helloworld-go-00001 1 True 1 1
NAME LATESTCREATED LATESTREADY READY REASON
configuration.serving.knative.dev/helloworld-go helloworld-go-00001 helloworld-go-00001 True
NAME URL READY REASON
route.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com True
再次访问，会发现现在访问速度快了很多：
[root@sh-saas-k8stest-master-dev-01 knative]# time curl -H "Host: helloworld-go.example.example.com" http://10.248.132.176
Hello Go Sample v1!
real 0m0.007s
user 0m0.001s
sys 0m0.003s
大约一分钟后，自动缩容到了0:
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl get all -n example
NAME READY STATUS RESTARTS AGE
pod/helloworld-go-00001-deployment-7754b949cb-whsqm 1/2 Terminating 0 66s
NAME TYPE CLUSTER-IP EXTERNAL-IP PORT(S) AGE
service/helloworld-go ExternalName <none> knative-local-gateway.istio-system.svc.cluster.local 80/TCP 7m11s
service/helloworld-go-00001 ClusterIP 10.248.140.210 <none> 80/TCP 7m22s
service/helloworld-go-00001-private ClusterIP 10.248.227.128 <none> 80/TCP,9090/TCP,9091/TCP,8022/TCP,8012/TCP 7m22s
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/helloworld-go-00001-deployment 0/0 0 0 7m22s
NAME DESIRED CURRENT READY AGE
replicaset.apps/helloworld-go-00001-deployment-7754b949cb 0 0 0 7m22s
NAME URL LATESTCREATED LATESTREADY READY REASON
service.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com helloworld-go-00001 helloworld-go-00001 True
NAME CONFIG NAME K8S SERVICE NAME GENERATION READY REASON ACTUAL REPLICAS DESIRED REPLICAS
revision.serving.knative.dev/helloworld-go-00001 helloworld-go helloworld-go-00001 1 True 0 0
NAME LATESTCREATED LATESTREADY READY REASON
configuration.serving.knative.dev/helloworld-go helloworld-go-00001 helloworld-go-00001 True
NAME URL READY REASON
route.serving.knative.dev/helloworld-go http://helloworld-go.example.example.com True
5. Knative Serving相关资源
通过以下命令可以查看Knative Serving的所有CRD资源：
[root@sh-saas-k8stest-master-dev-01 knative]# kubectl api-resources | grep knative
metrics autoscaling.internal.knative.dev true Metric
podautoscalers kpa,pa autoscaling.internal.knative.dev true PodAutoscaler
images img caching.internal.knative.dev true Image
certificates kcert networking.internal.knative.dev true Certificate
clusterdomainclaims cdc networking.internal.knative.dev false ClusterDomainClaim
ingresses kingress,king networking.internal.knative.dev true Ingress
serverlessservices sks networking.internal.knative.dev true ServerlessService
configurations config,cfg serving.knative.dev true Configuration
domainmappings dm serving.knative.dev true DomainMapping
revisions rev serving.knative.dev true Revision
routes rt serving.knative.dev true Route
services kservice,ksvc serving.knative.dev true Service
