- OpenShift 教程
- OpenShift - 主页
- OpenShift - 概述
- OpenShift - 类型
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- OpenShift - 基本概念
- OpenShift - 入门
- OpenShift - 构建自动化
- OpenShift-CLI
- OpenShift - CLI 操作
- OpenShift - 集群
- OpenShift - 应用程序扩展
- OpenShift - 管理
- OpenShift - Docker 和 Kubernetes
- OpenShift - 安全
- OpenShift 有用资源
- OpenShift - 快速指南
- OpenShift - 有用的资源
- OpenShift - 讨论
OpenShift - 入门
OpenShift 包含两种类型的中间件，用于通过 GUI 或 CLI 创建和部署应用程序。在本章中，我们将使用 CLI 创建一个新应用程序。我们将使用 OC 客户端与 OpenShift 环境进行通信。
创建新应用程序
在 OpenShift 中，可以通过三种方法创建新应用程序。
- 来自源代码
- 从图像
- 从模板
来自源代码
当我们尝试从源代码创建应用程序时，OpenShift 会查找存储库中应存在的 Docker 文件，该文件定义了应用程序构建流程。我们将使用 oc new-app 来创建一个应用程序。
使用存储库时要记住的第一件事是，它应该指向存储库中的源，OpenShift 将从中提取代码并构建它。
如果存储库克隆在安装了 OC 客户端的 Docker 机器上并且用户位于同一目录中，则可以使用以下命令创建它。
$ oc new-app . <Hear. Denotes current working directory>
以下是尝试从远程存储库为特定分支构建的示例。
$ oc new-app https://github.com/openshift/Testing-deployment.git#test1
这里，test1 是我们尝试在 OpenShift 中创建新应用程序的分支。
当在存储库中指定 Docker 文件时，我们需要定义构建策略，如下所示。
$ oc new-app OpenShift/OpenShift-test~https://github.com/openshift/Testingdeployment.git
从图像
使用镜像构建应用程序时，镜像存在于本地 Docker 服务器、内部托管的 Docker 存储库或 Docker hub 中。用户需要确保的唯一一件事是，他可以毫无问题地从中心提取图像。
OpenShift 能够确定所使用的源，无论是 Docker 映像还是源流。然而，如果用户希望他可以明确定义它是图像流还是 Docker 图像。
$ oc new-app - - docker-image tomcat
使用图像流 -
$ oc new-app tomcat:v1
从模板
模板可用于创建新应用程序。它可以是现有的模板或创建新的模板。
以下 yaml 文件基本上是可用于部署的模板。
apiVersion: v1
kind: Template
metadata:
name: <Name of template>
annotations:
description: <Description of Tag>
iconClass: "icon-redis"
tags: <Tages of image>
objects:
- apiVersion: v1
kind: Pod
metadata:
name: <Object Specification>
spec:
containers:
image: <Image Name>
name: master
ports:
- containerPort: <Container port number>
protocol: <Protocol>
labels:
redis: <Communication Type>
开发和部署 Web 应用程序
在 OpenShift 中开发新应用程序
为了在 OpenShift 中创建新的应用程序，我们必须编写新的应用程序代码并使用 OpenShift OC 构建命令进行构建。正如所讨论的，我们有多种创建新图像的方法。在这里，我们将使用模板来构建应用程序。当使用 oc new-app 命令运行时，此模板将构建一个新应用程序。
以下模板将创建 - 两个前端应用程序和一个数据库。除此之外，它将创建两个新服务，这些应用程序将部署到 OpenShift 集群。在构建和部署应用程序时，最初我们需要在 OpenShift 中创建一个命名空间，并在该命名空间下部署应用程序。
创建一个新的命名空间
$ oc new-project openshift-test --display-name = "OpenShift 3 Sample" -- description = "This is an example project to demonstrate OpenShift v3"
模板
{
"kind": "Template",
"apiVersion": "v1",
"metadata": {
"name": "openshift-helloworld-sample",
"creationTimestamp": null,
"annotations": {
"description": "This example shows how to create a simple openshift
application in openshift origin v3",
"iconClass": "icon-openshift",
"tags": "instant-app,openshift,mysql"
}
}
},
对象定义
模板中的秘密定义
"objects": [
{
"kind": "Secret",
"apiVersion": "v1",
"metadata": {"name": "dbsecret"},
"stringData" : {
"mysql-user" : "${MYSQL_USER}",
"mysql-password" : "${MYSQL_PASSWORD}"
}
},
模板中的服务定义
{
"kind": "Service",
"apiVersion": "v1",
"metadata": {
"name": "frontend",
"creationTimestamp": null
},
"spec": {
"ports": [
{
"name": "web",
"protocol": "TCP",
"port": 5432,
"targetPort": 8080,
"nodePort": 0
}
],
"selector": {"name": "frontend"},
"type": "ClusterIP",
"sessionAffinity": "None"
},
"status": {
"loadBalancer": {}
}
},
模板中的路由定义
{
"kind": "Route",
"apiVersion": "v1",
"metadata": {
"name": "route-edge",
"creationTimestamp": null,
"annotations": {
"template.openshift.io/expose-uri": "http://{.spec.host}{.spec.path}"
}
},
"spec": {
"host": "www.example.com",
"to": {
"kind": "Service",
"name": "frontend"
},
"tls": {
"termination": "edge"
}
},
"status": {}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "origin-openshift-sample",
"creationTimestamp": null
},
"spec": {},
"status": {
"dockerImageRepository": ""
}
},
{
"kind": "ImageStream",
"apiVersion": "v1",
"metadata": {
"name": "openshift-22-ubuntu7",
"creationTimestamp": null
},
"spec": {
"dockerImageRepository": "ubuntu/openshift-22-ubuntu7"
},
"status": {
"dockerImageRepository": ""
}
},
在模板中构建配置定义
{
"kind": "BuildConfig",
"apiVersion": "v1",
"metadata": {
"name": "openshift-sample-build",
"creationTimestamp": null,
"labels": {name": "openshift-sample-build"}
},
"spec": {
"triggers": [
{ "type": "GitHub",
"github": {
"secret": "secret101" }
},
{
"type": "Generic",
"generic": {
"secret": "secret101",
"allowEnv": true }
},
{
"type": "ImageChange",
"imageChange": {}
},
{ "type": "ConfigChange”}
],
"source": {
"type": "Git",
"git": {
"uri": https://github.com/openshift/openshift-hello-world.git }
},
"strategy": {
"type": "Docker",
"dockerStrategy": {
"from": {
"kind": "ImageStreamTag",
"name": "openshift-22-ubuntu7:latest”
},
"env": [
{
"name": "EXAMPLE",
"value": "sample-app"
}
]
}
},
"output": {
"to": {
"kind": "ImageStreamTag",
"name": "origin-openshift-sample:latest"
}
},
"postCommit": {
"args": ["bundle", "exec", "rake", "test"]
},
"status": {
"lastVersion": 0
}
}
},
模板中的部署配置
"status": {
"lastVersion": 0
}
{
"kind": "DeploymentConfig",
"apiVersion": "v1",
"metadata": {
"name": "frontend",
"creationTimestamp": null
}
},
"spec": {
"strategy": {
"type": "Rolling",
"rollingParams": {
"updatePeriodSeconds": 1,
"intervalSeconds": 1,
"timeoutSeconds": 120,
"pre": {
"failurePolicy": "Abort",
"execNewPod": {
"command": [
"/bin/true"
],
"env": [
{
"name": "CUSTOM_VAR1",
"value": "custom_value1"
}
]
}
}
}
}
}
"triggers": [
{
"type": "ImageChange",
"imageChangeParams": {
"automatic": true,
"containerNames": [
"openshift-helloworld"
],
"from": {
"kind": "ImageStreamTag",
"name": "origin-openshift-sample:latest"
}
}
},
{
"type": "ConfigChange"
}
],
"replicas": 2,
"selector": {
"name": "frontend"
},
"template": {
"metadata": {
"creationTimestamp": null,
"labels": {
"name": "frontend"
}
},
"spec": {
"containers": [
{
"name": "openshift-helloworld",
"image": "origin-openshift-sample",
"ports": [
{
"containerPort": 8080,
"protocol": "TCP”
}
],
"env": [
{
"name": "MYSQL_USER",
"valueFrom": {
"secretKeyRef" : {
"name" : "dbsecret",
"key" : "mysql-user"
}
}
},
{
"name": "MYSQL_PASSWORD",
"valueFrom": {
"secretKeyRef" : {
"name" : "dbsecret",
"key" : "mysql-password"
}
}
},
{
"name": "MYSQL_DATABASE",
"value": "${MYSQL_DATABASE}"
}
],
"resources": {},
"terminationMessagePath": "/dev/termination-log",
"imagePullPolicy": "IfNotPresent",
"securityContext": {
"capabilities": {},
"privileged": false
}
}
],
"restartPolicy": "Always",
"dnsPolicy": "ClusterFirst"
},
"status": {}
},
模板中的服务定义
{
"kind": "Service",
"apiVersion": "v1",
"metadata": {
"name": "database",
"creationTimestamp": null
},
"spec": {
"ports": [
{
"name": "db",
"protocol": "TCP",
"port": 5434,
"targetPort": 3306,
"nodePort": 0
}
],
"selector": {
"name": "database
},
"type": "ClusterIP",
"sessionAffinity": "None" },
"status": {
"loadBalancer": {}
}
},
模板中的部署配置定义
{
"kind": "DeploymentConfig",
"apiVersion": "v1",
"metadata": {
"name": "database",
"creationTimestamp": null
},
"spec": {
"strategy": {
"type": "Recreate",
"resources": {}
},
"triggers": [
{
"type": "ConfigChange"
}
],
"replicas": 1,
"selector": {"name": "database"},
"template": {
"metadata": {
"creationTimestamp": null,
"labels": {"name": "database"}
},
"template": {
"metadata": {
"creationTimestamp": null,
"labels": {
"name": "database"
}
},
"spec": {
"containers": [
{
"name": "openshift-helloworld-database",
"image": "ubuntu/mysql-57-ubuntu7:latest",
"ports": [
{
"containerPort": 3306,
"protocol": "TCP"
}
],
"env": [
{
"name": "MYSQL_USER",
"valueFrom": {
"secretKeyRef" : {
"name" : "dbsecret",
"key" : "mysql-user"
}
}
},
{
"name": "MYSQL_PASSWORD",
"valueFrom": {
"secretKeyRef" : {
"name" : "dbsecret",
"key" : "mysql-password"
}
}
},
{
"name": "MYSQL_DATABASE",
"value": "${MYSQL_DATABASE}"
}
],
"resources": {},
"volumeMounts": [
{
"name": "openshift-helloworld-data",
"mountPath": "/var/lib/mysql/data"
}
],
"terminationMessagePath": "/dev/termination-log",
"imagePullPolicy": "Always",
"securityContext": {
"capabilities": {},
"privileged": false
}
}
],
"volumes": [
{
"name": "openshift-helloworld-data",
"emptyDir": {"medium": ""}
}
],
"restartPolicy": "Always",
"dnsPolicy": "ClusterFirst”
}
}
},
"status": {}
},
"parameters": [
{
"name": "MYSQL_USER",
"description": "database username",
"generate": "expression",
"from": "user[A-Z0-9]{3}",
"required": true
},
{
"name": "MYSQL_PASSWORD",
"description": "database password",
"generate": "expression",
"from": "[a-zA-Z0-9]{8}",
"required": true
},
{
"name": "MYSQL_DATABASE",
"description": "database name",
"value": "root",
"required": true
}
],
"labels": {
"template": "application-template-dockerbuild"
}
}
上面的模板文件需要一次性编译完成。我们需要首先将所有内容复制到一个文件中，完成后将其命名为 yaml 文件。
我们需要运行以下命令来创建应用程序。
$ oc new-app application-template-stibuild.json
--> Deploying template openshift-helloworld-sample for "application-template-stibuild.json"
openshift-helloworld-sample
---------
This example shows how to create a simple ruby application in openshift origin v3
* With parameters:
* MYSQL_USER = userPJJ # generated
* MYSQL_PASSWORD = cJHNK3se # generated
* MYSQL_DATABASE = root
--> Creating resources with label app = ruby-helloworld-sample ...
service "frontend" created
route "route-edge" created
imagestream "origin-ruby-sample" created
imagestream "ruby-22-centos7" created
buildconfig "ruby-sample-build" created
deploymentconfig "frontend" created
service "database" created
deploymentconfig "database" created
--> Success
Build scheduled, use 'oc logs -f bc/ruby-sample-build' to track its progress.
Run 'oc status' to view your app.
如果我们希望监控构建，可以使用 -
$ oc get builds NAME TYPE FROM STATUS STARTED DURATION openshift-sample-build-1 Source Git@bd94cbb Running 7 seconds ago 7s
我们可以使用以下命令检查 OpenShift 上部署的应用程序：
$ oc get pods NAME READY STATUS RESTARTS AGE database-1-le4wx 1/1 Running 0 1m frontend-1-e572n 1/1 Running 0 27s frontend-1-votq4 1/1 Running 0 31s opeshift-sample-build-1-build 0/1 Completed 0 1m
我们可以检查应用程序服务是否是根据服务定义创建的
$ oc get services NAME CLUSTER-IP EXTERNAL-IP PORT(S) SELECTOR AGE database 172.30.80.39 <none> 5434/TCP name=database 1m frontend 172.30.17.4 <none> 5432/TCP name=frontend 1m