Tekton 是一个功能强大且灵活的 Kubernetes 原生开源框架，用于创建持续集成和交付（CI/CD）系统。通过抽象底层实现细节，用户可以跨多云平台和本地系统进行构建、测试和部署。
本文是基于阿里云Kubernetes服务部署Tekton Pipeline，并使用它完成源码拉取、应用打包、镜像推送和应用部署的实践过程。
Tekton Pipeline中有5类对象,核心理念是通过定义yaml定义构建过程.构建任务的状态存放在status字段中。
其中5类对象分别是：PipelineResouce、Task、TaskRun、Pipeline、PipelineRun。
Task是单个任务的构建过程,需要通过定义TaskRun任务去运行Task。
Pipeline包含多个Task,并在此基础上定义input和output,input和output以PipelineResource作为交付。
PipelineResource是可用于input和output的对象集合。
同样地,需要定义PipelineRun才会运行Pipeline。
1. 在阿里云Kubernetes集群中部署Tekton Pipeline
kubectl apply --filename https://storage.googleapis.com/tekton-releases/latest/release.yaml
查看Tekton Pipelines组件是否运行正常：
$ kubectl -n tekton-pipelines get po
NAME READY STATUS RESTARTS AGE
tekton-pipelines-controller-6bcd7ff5d6-vzmrh 1/1 Running 0 25h
tekton-pipelines-webhook-6856cf9c47-l6nj6 1/1 Running 0 25h
2. 创建Git Resource， Registry Resource
编辑 git-pipeline-resource.yaml :
apiVersion: tekton.dev/v1alpha1
kind: PipelineResource
metadata:
name: git-pipeline-resource
spec:
type: git
params:
- name: revision
value: tekton
- name: url
value: https://code.aliyun.com/haoshuwei/jenkins-demo.git
git repo的分支名称为 tekton 。
编辑 registry-pipeline-resource.yaml :
apiVersion: tekton.dev/v1alpha1
kind: PipelineResource
metadata:
name: registry-pipeline-resource
spec:
type: image
params:
- name: url
value: registry.cn-hangzhou.aliyuncs.com/haoshuwei/tekton-demo
容器镜像仓库地址为 registry.cn-hangzhou.aliyuncs.com/haoshuwei/tekton-demo， 标签为 latest
创建pipeline resource：
$ kubectl -n tekton-pipelines create -f git-pipeline-resource.yaml
$ kubectl -n tekton-pipelines create -f registry-pipeline-resource.yaml
查看已创建的pipeline resource资源：
$ kubectl -n tekton-pipelines get PipelineResource
NAME AGE
git-pipeline-resource 2h
registry-pipeline-resource 2h
3. 创建Git Repo/Docker Registry Authentication
拉取私有git源码项目需要配置使用Git Repo Authentication；拉取和推送docker镜像需要配置Docker Registry Authentication。在Tekton Pipeline中，Git Repo/Docker Registry Authentication会被定义成ServiceAccount来使用。
编辑 secret tekton-basic-user-pass-git.yaml :
apiVersion: v1
kind: Secret
metadata:
name: tekton-basic-user-pass-git
annotations:
tekton.dev/git-0: https://code.aliyun.com
type: kubernetes.io/basic-auth
stringData:
username: <cleartext non-encoded>
password: <cleartext non-encoded>
编辑 secret tekton-basic-user-pass-registry.yaml :
apiVersion: v1
kind: Secret
metadata:
name: tekton-basic-user-pass-registry
annotations:
tekton.dev/docker-0: https://registry.cn-hangzhou.aliyuncs.com
type: kubernetes.io/basic-auth
stringData:
username: <cleartext non-encoded>
password: <cleartext non-encoded>
编辑 serviceaccount tekton-git-and-registry.yaml :
apiVersion: v1
kind: ServiceAccount
metadata:
name: tekton-git-and-registry
secrets:
- name: tekton-basic-user-pass-git
- name: tekton-basic-user-pass-registry
创建serviceaccount：
$ kubectl -n tekton-pipelines create -f tekton-basic-user-pass-git.yaml
$ kubectl -n tekton-pipelines create -f tekton-basic-user-pass-registry.yaml
$ kubectl -n tekton-pipelines create -f tekton-git-and-registry.yaml
查看secret以及sa：
$ kubectl -n tekton-pipelines get secret
NAME TYPE DATA AGE
default-token-pwncj kubernetes.io/service-account-token 3 25h
tekton-basic-user-pass-git kubernetes.io/basic-auth 2 151m
tekton-basic-user-pass-registry kubernetes.io/basic-auth 2 151m
tekton-git-and-registry-token-tr95m kubernetes.io/service-account-token 3 151m
tekton-pipelines-controller-token-lc2fv kubernetes.io/service-account-token 3 25h
webhook-certs Opaque 3 25h
$ kubectl -n tekton-pipelines get sa
NAME SECRETS AGE
default 1 25h
tekton-git-and-registry 3 152m
tekton-pipelines-controller 1 25h
4. 配置serviceaccount tekton-git-and-registry获取命名空间tekton-pipelines的管理权限用于部署应用
创建ClusterRoleBinding tekton-cluster-admin :
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
name: tekton-cluster-admin
subjects:
- kind: ServiceAccount
name: tekton-git-and-registry
namespace: tekton-pipelines
roleRef:
kind: ClusterRole
name: cluster-admin
apiGroup: rbac.authorization.k8s.io
5. 创建一个Task
创建task build-app.yaml :
apiVersion: tekton.dev/v1alpha1
kind: Task
metadata:
name: build-app
spec:
inputs:
resources:
- name: java-demo
type: git
params:
- name: pathToDockerFile
description: The path to the dockerfile to build
default: /workspace/java-demo/Dockerfile
- name: pathToContext
description: The build context used by Kaniko
default: /workspace/java-dem
- name: pathToYaml
description: The path to teh manifest to apply
outputs:
resources:
- name: builtImage
type: image
steps:
- name: build-mvn-package
image: registry.cn-beijing.aliyuncs.com/acs-sample/jenkins-slave-maven:3.3.9-jdk-8-alpine
workingDir: /workspace/java-demo
command:
- mvn
args:
- package
- -B
- -DskipTests
- name: build-docker-image
image: registry.cn-beijing.aliyuncs.com/acs-sample/jenkins-slave-kaniko:0.6.0
command:
- kaniko
args:
- --dockerfile=${inputs.params.pathToDockerFile}
- --destination=${outputs.resources.builtImage.url}
- --context=${inputs.params.pathToContext}
- name: deploy-app
image: registry.cn-beijing.aliyuncs.com/acs-sample/jenkins-slave-kubectl:1.11.5
command:
- kubectl
args:
- apply
- -f
- ${inputs.params.pathToYaml}
6. 创建TaskRun运行任务
创建taskrun build-app-task-run.yaml :
apiVersion: tekton.dev/v1alpha1
kind: TaskRun
metadata:
name: build-app-task-run
spec:
serviceAccount: tekton-git-and-registry
taskRef:
name: build-app
trigger:
type: manual
inputs:
resources:
- name: java-demo
resourceRef:
name: git-pipeline-resource
params:
- name: pathToDockerFile
value: Dockerfile
- name: pathToContext
value: /workspace/java-demo
- name: pathToYaml
value: /workspace/java-demo/deployment.yaml
outputs:
resources:
- name: builtImage
resourceRef:
name: registry-pipeline-resource
7. 查看构建状态以及日志
查看taskrun状态：
$ kubectl -n tekton-pipelines get taskrun
NAME SUCCEEDED REASON STARTTIME COMPLETIONTIME
build-app-task-run Unknown Pending 4s
查看构建日志：
$ kubectl -n tekton-pipelines get po
NAME READY STATUS RESTARTS AGE
build-app-task-run-pod-b8f890 3/5 Running 0 75s
tekton-pipelines-controller-6bcd7ff5d6-vzmrh 1/1 Running 0 25h
tekton-pipelines-webhook-6856cf9c47-l6nj6 1/1 Running 0 25h
$ kubectl -n tekton-pipelines logs -f build-app-task-run-pod-b8f890
Error from server (BadRequest): a container name must be specified for pod build-app-task-run-pod-b8f890, choose one of: [build-step-git-source-git-pipeline-resource-77l5v build-step-build-mvn-package build-step-build-docker-image build-step-deploy-app nop] or one of the init containers: [build-step-credential-initializer-8dsnm build-step-place-tools]
mvn build的日志:
$ kubectl -n tekton-pipelines logs -f build-app-task-run-pod-b8f890 -c build-step-build-mvn-package
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building jenkins-demo-web 1.0.0-SNAPSHOT
[INFO] ------------------------------------------------------------------------
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-resources-plugin/2.6/maven-resources-plugin-2.6.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-resources-plugin/2.6/maven-resources-plugin-2.6.pom (8 KB at 7.3 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/23/maven-plugins-23.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/plugins/maven-plugins/23/maven-plugins-23.pom (9 KB at 26.7 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/maven/maven-parent/22/maven-parent-22.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/maven/maven-parent/22/maven-parent-22.pom (30 KB at 61.3 KB/sec)
[INFO] Downloading: https://repo.maven.apache.org/maven2/org/apache/apache/11/apache-11.pom
[INFO] Downloaded: https://repo.maven.apache.org/maven2/org/apache/apache/11/apache-11.pom (15 KB at 45.3 KB/sec)
....
docker build的日志：
$ kubectl -n tekton-pipelines logs -f build-app-task-run-pod-b8f890 -c build-step-build-docker-image
INFO[0000] Downloading base image tomcat
2019/05/06 11:58:46 No matching credentials were found, falling back on anonymous
INFO[0003] Taking snapshot of full filesystem...
INFO[0003] Skipping paths under /builder/home, as it is a whitelisted directory
INFO[0003] Skipping paths under /builder/tools, as it is a whitelisted directory
INFO[0003] Skipping paths under /dev, as it is a whitelisted directory
INFO[0003] Skipping paths under /kaniko, as it is a whitelisted directory
INFO[0003] Skipping paths under /proc, as it is a whitelisted directory
INFO[0003] Skipping paths under /run/secrets/kubernetes.io/serviceaccount, as it is a whitelisted directory
INFO[0003] Skipping paths under /sys, as it is a whitelisted directory
INFO[0003] Skipping paths under /var/run, as it is a whitelisted directory
INFO[0003] Skipping paths under /workspace, as it is a whitelisted directory
INFO[0003] Using files from context: [/workspace/java-demo/target/demo.war]
INFO[0003] ADD target/demo.war /usr/local/tomcat/webapps/demo.war
INFO[0003] Taking snapshot of files...
...
app-deploy的日志：
$ kubectl -n tekton-pipelines logs -f build-app-task-run-pod-637855 -c build-step-deploy-app
deployment.extensions/jenkins-java-demo created
service/jenkins-java-demo created
taskrun的完成状态为True则构建部署过程完成：
$ kubectl -n tekton-pipelines get taskrun
NAME SUCCEEDED REASON STARTTIME COMPLETIONTIME
build-app-task-run True 4m 2m
8. 小结
Tekton Pipeline中任务模板可以拿来复用，而不需要重复定义，另外通过CRD重新定义CI/CD是一大亮点,初学者可能会觉得有些绕。
持续实验持续更新中。
本文作者：流生
本文为云栖社区原创内容，未经允许不得转载。