OpenShift - 入门

OpenShift包含两种类型的中位数，可通过GUI或CLI创建和部署应用程序.在本章中，我们将使用CLI来创建新的应用程序.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，有三种创建新方法的方法申请.

• 来自源代码

• 来自图片

• 来自模板

来自源代码

当我们尝试从中创建应用程序时源代码，OpenShift查找应该存在于repo中的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repo时要记住的第一件事是，它应该指向来自OpenShift将拉动的repo中的原点代码并构建它.

如果在安装了OC客户端且用户位于同一目录内的Docker机器上克隆了repo，则可以使用以下命令创建它.

$ oc new-app . 

以下是尝试从特定分支的远程仓库进行构建的示例.

$ 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.

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

使用图像构建应用程序时，图像存在于本地Docker服务器，内部托管的Docker存储库中，或者Docker中心.用户唯一需要确保的是，他有权从集线器中提取图像而没有任何问题.

OpenShift能够确定使用的来源，无论是Docker镜像或源流.但是，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.它可以是现有模板或创建新模板.

以下yaml文件基本上是一个可用于部署的模板.

apiVersion: v1kind: Templatemetadata:   name:    annotations:      description:       iconClass: "icon-redis"      tags: objects:   - apiVersion: v1   kind: Pod   metadata:      name: spec:   containers:      image:       name: master      ports:      - containerPort:          protocol: labels:   redis: 

开发和部署Web应用程序

在OpenShift中开发新应用程序

为了在OpenShift中创建一个新的应用程序，我们必须编写一个新的应用程序代码并使用OpenShift OC构建命令构建它.如上所述，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，它还将创建两个新服务，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中创建命名空间并在该命名空间下部署应用程序.

创建新命名空间

$ 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

秘密定义模板中的离子

"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": {}   }},

模板中的路线定义

{   "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"    } }

上述模板文件需要立即编译.我们需要先将所有内容复制到一个文件中，并在完成后将其命名为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 buildsNAME                        TYPE      FROM          STATUS     STARTED         DURATIONopenshift-sample-build-1    Source   Git@bd94cbb    Running    7 seconds ago   7s

我们可以使用 : 检查OpenShift上已部署的应用程序;

$ oc get podsNAME                            READY   STATUS      RESTARTS   AGEdatabase-1-le4wx                1/1     Running     0          1mfrontend-1-e572n                1/1     Running     0          27sfrontend-1-votq4                1/1     Running     0          31sopeshift-sample-build-1-build   0/1     Completed   0          1m

我们可以检查是否根据服务创建了应用程序服务定义使用

$ oc get servicesNAME        CLUSTER-IP      EXTERNAL-IP     PORT(S)      SELECTOR          AGEdatabase    172.30.80.39             5434/TCP     name=database      1mfrontend    172.30.17.4              5432/TCP     name=frontend      1m