在完成了《OpenShift 4 之Knative(1) – 创建Knative无服务器架构环境)》后，我们开始部署一个基于Knative的Serverless应用。本文先部署一个Serverless应用。作为对比，然后部署一个非Serverless应用，最后对比两个应用的运行效果。
部署非Serverless应用(dumpy)
1. 创建项目和权限
$ oc new-project kn-demo
$ oc create serviceaccount pipeline
$ oc adm policy add-scc-to-user privileged -z pipeline
$ oc adm policy add-role-to-user edit -z pipeline 2. 允许在tekton中使用openshift-client
$ oc create -f 3. 为Tekton创建可以使用go S2I的Task
$ oc create -f 创建tekton的Pipeline和调用Rource
$ oc create -f
$ oc create -f
$ oc create -f
$ tkn tasks list
NAME AGE
openshift-client 9 minutes ago
$ tkn pipeline list
NAME AGE LAST RUN STARTED DURATION STATUS
deploy-pipeline 3 minutes ago --- --- --- ---
$ tkn resource list
NAME TYPE DETAILS
sourcecode-git git url:
applicat io n-image image url: image-registry.openshift-image-registry.svc:5000/kn-demo/dumpy 4. 启动运行Tekton Pipeline
$ tkn pipeline start deploy-pipeline -s pipeline -r app-git=sourcecode- git -r app-image=application-image
Pipelinerun started: deploy-pipeline-run-m65rw
Showing logs...
[build : create-dir-image-wj45n] {"level":"warn","ts":1576916492.4300456,"logger":"fallback-logger","caller":"logging/ config .go:69"," msg ":"Fetch GitHub commit ID from kodata failed: \"KO_DATA_PATH\" does not exist or is empty"}
[build : create-dir-image-wj45n] {"level":"info","ts":1576916492.4334698,"logger":"fallback-logger","caller":"bash/main.go:64","msg":"Successfully executed command \"sh -c mkdir -p /workspace/ output /image\"; output "}
[build : git-source-sourcecode-git-h5kt6] {"level":"warn","ts":1576916492.9045074,"logger":"fallback-logger","caller":"logging/config.go:69","msg":"Fetch GitHub commit ID from kodata failed: \"KO_DATA_PATH\" does not exist or is empty"}
[build : git-source-sourcecode-git-h5kt6] {"level":"info","ts":1576916496.1496713,"logger":"fallback-logger","caller":"git/git.go:103","msg":"Successfully cloned @ master in path /workspace/source"}
[build : generate] Application dockerfile generated in /gen-source/Dockerfile.gen
[build : build] STEP 1: FROM registry.access.redhat.com/devtools/go-toolset-rhel7
。。。
[build : build] STEP 2: LABEL "io.openshift.s2i.build.image"="registry.access.redhat.com/devtools/go-toolset-rhel7" "io.openshift.s2i.build.source-location"="."
。。。
[build : build] STEP 3: USER root
。。。
[build : build] STEP 4: COPY upload/src /tmp/src
。。。
[build : build] STEP 5: RUN chown -R 1001:0 /tmp/src
。。。
[build : build] STEP 6: USER 1001
。。。
[build : build] STEP 7: RUN /usr/libexec/s2i/assemble
。。。
[build : build] STEP 8: CMD /usr/libexec/s2i/run
[build : build] STEP 9: COMMIT image-registry.openshift-image-registry.svc:5000/kn-demo/dumpy
。。。
[build : image-digest-exporter-vk4tr] {"level":"warn","ts":1576916688.3277884,"logger":"fallback-logger","caller":"logging/config.go:69","msg":"Fetch GitHub commit ID from kodata failed: \"KO_DATA_PATH\" does not exist or is empty"}
[build : image-digest-exporter-vk4tr] {"level":"info","ts":1576916688.3279572,"logger":"fallback-logger","caller":"imagedigestexporter/main.go:58","msg":"ImageResource application-image doesn't have an index.json file: stat /builder/home/image-outputs/image/index.json: no such file or directory"}
[deploy : oc] deploymentconfig.apps.openshift.io/dumpy rolled out 5. 也可以用一下方式查看Tekton Pipeline的日志。
$ tkn pipeline list
NAME AGE LAST RUN STARTED DURATION STATUS
deploy-pipeline 19 minutes ago deploy-pipeline-run-m65rw 15 minutes ago 7 minutes Succeeded
$ tkn pipelinerun logs -f deploy-pipeline-run-m65rw 6. Tekton Pipeline完成后可以在OpenShift Console的Developer视图中看到以下Pipelines中的deploy-pipeline运行状态。
7. 访问dumpy应用的Route地址，验证应用是可以访问的。
$ oc get route
NAME HOST/PORT PATH SERVICES PORT TERMINATION WILDCARD
dumpy dumpy-kn-demo.apps-crc.testing dumpy 8080-tcp None
$ curl
888 888 888
888 888 888
888 888 888
888d888 .d88b. .d88888 88888b. 8888b. 888888
888P" d8P Y8bd88" 888 888 "88b "88b888
888 88888888888 888 888 888.d888888888
888 Y8b. Y88b 888 888 888888 888Y88b.
888 "Y8888 "Y88888 888 888"Y888888 "Y888 部署Knative Serverless应用
1. 基于上一步生成的dumpy的ImageStream创建名为dumpy-serverless的Tekton的Service。
$ oc describe is dumpy
Name:dumpy
Namespace:kn-demo
Created:2 hours ago
Labels:app=dump
Annotations:<none>
Image Repository:default-route-openshift-image-registry.apps-crc.testing/kn-demo/dumpy
Image Lookup:local=false
Unique Images:1
Tags:1
latest
no spec tag
. image-registry.openshift-image-registry.svc:5000/kn-demo/dumpy@sha256:9c5b1dc90f9b9fc54b1dec625251340d8b774e15bcad6664869c3db8529314f0
$ kn service create dumpy-serverless --image=image-registry.openshift-image-registry.svc:5000/kn-demo/dumpy -l app.kubernetes.io/name=golang
Creating service 'dumpy-serverless' in namespace 'kn-demo':
0.136s The Route is still working to reflect the latest desired specification.
0.161s Configuration "dumpy-serverless" is waiting for a Revision to become ready.
28.368s ...
28.551s Ingress has not yet been reconciled.
69.596s Ready to serve. 2. 用OpenShift Console的Administrator或命令行查看Knative相关资源的状态。
其中“kn service list”命令等同“oc get ksvc”命令；”kn revision list”命令等同“oc get revision”命令；“kn route list”命令等同
$ kn service list
NAME URL LATEST AGE CONDITIONS READY REASON
dumpy-serverless dumpy-serverless-tbcvz-1 79m 3 OK / 3 True
$ oc get ksvc -n kn-demo
NAME URL LATESTCREATED LATESTREADY READY REASON
dumpy-serverless dumpy-serverless-tbcvz-1 dumpy-serverless-tbcvz-1 True
$ kn revision list
NAME SERVICE GENERATION AGE CONDITIONS READY REASON
dumpy-serverless-tbcvz-1 dumpy-serverless 1 79m 3 OK / 4 True
$ oc get revision -n kn-demo
NAME CONFIG NAME K8S SERVICE NAME GENERATION READY REASON
dumpy-serverless-tbcvz-1 dumpy-serverless dumpy-serverless-tbcvz-1 1 True
$ kn route list
NAME URL READY
dumpy-serverless True
$ oc get route.serving.knative.dev -n kn-demo
NAME URL READY REASON
dumpy-serverless True 
3. 访问dumpy-serverless应用的Route地址，验证应用是可以访问的。
$ kn route list
NAME URL READY
dumpy-serverless True
$ curl
888 888 888
888 888 888
888 888 888
888d888 .d88b. .d88888 88888b. 8888b. 888888
888P" d8P Y8bd88" 888 888 "88b "88b888
888 88888888888 888 888 888.d888888888
888 Y8b. Y88b 888 888 888888 888Y88b.
888 "Y8888 "Y88888 888 888"Y888888 "Y888 # 对比dumpy与dumpy-serverless
1. 将运行dumpy应用的 Pod 减到“0”个：
$ oc idle dumpy
WARNING: idling when network policies are in place may cause connections to bypass network policy entirely
The service "kn-demo/dumpy" has been marked as idled
The service will unidle DeploymentConfig "kn-demo/dumpy" to 1 replicas once it receives traffic
DeploymentConfig "kn-demo/dumpy" has been idled 2. 此时查看运行dumpy应用与dumpy-serverless应用的Pod情况。注意2个应用都没有对应的Pod，其中dumpy是手工减到“0”的，而dumpy-serverless是Knative自动减到”0″的。
$ oc get pod -w
NAME READY STATUS RESTARTS AGE
deploy-pipeline-run-m65rw-build-zc926-pod-4c22ce 0/6 Completed 0 70m
deploy-pipeline-run-m65rw-deploy-wtz72-pod-6bf2ef 0/1 Completed 0 63m
dumpy-1-deploy 0/1 Completed 0 63m 3. 此时在OpenShift Console的Developer视图的Toplogy看到的是下图状态：
4. 执行命令分别访问dumpy应用与dumpy-serverless应用。
```bash
$ curl
888 888 888
888 888 888
888 888 888
888d888 .d88b. .d88888 88888b. 8888b. 888888
888P" d8P Y8bd88" 888 888 "88b "88b888
888 88888888888 888 888 888.d888888888
888 Y8b. Y88b 888 888 888888 888Y88b.
888 "Y8888 "Y88888 888 888"Y888888 "Y888
$ curl
888 888 888
888 888 888
888 888 888
888d888 .d88b. .d88888 88888b. 8888b. 888888
888P" d8P Y8bd88" 888 888 "88b "88b888
888 88888888888 888 888 888.d888888888
888 Y8b. Y88b 888 888 888888 888Y88b.
888 "Y8888 "Y88888 888 888"Y888888 "Y888
``` 5. 用（2）持续监控Pod的情况，其中运行dumpy应用的Pod在增加到”1″后不会自动减到“0”，而dumpy-servless的应用在响应用户请求后会自动减到“0”。此时在OpenShift Console上确认dumpy-servless应用的状态如下图。
