openshift/origin工作记录（1）——S2I镜像定制(基于SVN)

上周的工作内容是迁移微服务管控平台到openshift集群上。定制了基于git的S2I，走通了从gitlab拉取代码、打包、部署等一系列流程，成功迁移并向部门老大做了汇报。
本周的工作是定制基于SVN的S2I，走通从SVN拉取代码、打包、部署这套流程。

本篇博客所用到的代码已上传至github。https://github.com/hu12081/openshift-s2i-tomcat-svn.git

s2i源码研究（能力不够，修改失败）

周一的时候在github上粗略阅读了source-to-image的源码，代码地址为https://github.com/openshift/source-to-image。整体代码采用go语言实现，https://github.com/openshift/source-to-image/tree/master/pkg/scm/downloaders目录下的代码应该是实现代码下载功能的，包括从本地文件路径拷贝代码、通过git克隆代码。

无奈对go语言一窍不通，如果从零学习go语言修改s2i的代码，短期内无法实现。强行建议老大抛弃openshift s2i那一套，走jkenins（虽然我还是一窍不通，但组内有人会，可以把锅甩出去。。。），老大基本被我说服。

修改builder镜像，定制部署模板（成功实现）

周二在看《开源容器云openshift》一书时，无意在书中发现作者的github，上面就有svn的demo，地址为https://github.com/nichochen/openshift-tomcat-svn。着实尴尬。

该项目的最后提交时间为两年前，在尝试部署的过程中发现存在以下问题：

1.ose-json文件夹下的openshift-tomcat7-svn-is.json存在语法错误。
2.该部署模板虽然集成了svn，但是在web界面上必须填写可用的git地址（该地址只用于跳过s2i验证），作者在README.md指出了该缺陷，缺没有修复。
3.没有提供svn的账号、密码输入功能。
4.直接clone该项目，在builder镜像的使用过程中，会报文件夹权限的问题。

优化已有的开源项目

参考我的博客openshift/origin学习记录（9）——S2I镜像定制(基于Git)
以下内容有做了一些定制化开发（基本都有表明）不具有通用性，不推荐直接复制粘贴使用！！！请自行修改参数、指令等内容。

创建S2I Builder镜像工作目录

通过s2i create命令创建一个名为tomcat-s2i的S2I Builder镜像。第二个参数tomcat-svn为S2I Builder镜像名称。第三个参数tomcat-svn-catalog定义了工作目录的名称。

s2i create tomcat-svn tomcat-svn-catalog

编写Dockerfile

修改tomcat-svn-catalog目录下的Dockerfile文件。

# openshift-tomcat8-svnFROM docker.io/centos# TODO: Put the maintainer name in the image metadataMAINTAINER huliaoliao# TODO: Rename the builder environment variable to inform users about application you provide themENV BUILDER_VERSION 1.0# TODO: Set labels used in OpenShift to describe the builder imageLABEL io.openshift.s2i.scripts-url=image:///usr/libexec/s2i \      io.k8s.description="Platform for building tomcat" \      io.k8s.display-name="builder tomcat" \      io.openshift.expose-services="8080:http" \      io.openshift.tags="builder,tomcat,java,etc."# TODO: Install required packages here:COPY ./CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repoRUN yum makecache &&  yum install -y java-1.8.0-openjdk subversion maven && yum clean all -yCOPY ./s2i/bin/ /usr/libexec/s2i# TODO (optional): Copy the builder files into /opt/app-rootCOPY ./tomcat8/ /opt/app-root/tomcat8# TODO: Copy the S2I scripts to /usr/local/s2i, since openshift/base-centos7 image sets io.openshift.s2i.scripts-url label that way, or update that label#COPY ./s2i/bin/ /usr/libexec/s2i# TODO: Drop the root user and make the content of /opt/app-root owned by user 1001RUN useradd -m tomcat -u 1002 && \    chmod -R a+rw /opt && \    chmod -R a+rw /opt/app-root && \    chmod a+rwx /opt/app-root/tomcat8/* && \    chmod +x /opt/app-root/tomcat8/bin/*.sh && \    rm -rf /opt/app-root/tomcat8/webapps/* && \    rm -rf /usr/share/maven/conf/settings.xmlADD ./settings.xml /usr/share/maven/conf/# This default user is created in the openshift/base-centos7 imageUSER 1002# TODO: Set the default port for applications built using this imageEXPOSE 8080ENTRYPOINT []# TODO: Set the default CMD for the imageCMD ["/usr/libexec/s2i/usage"]

其中COPY ./CentOS-Base.repo /etc/yum.repos.d/CentOS-Base.repo是为了换源。rm -rf /usr/share/maven/conf/settings.xml和ADD ./settings.xml /usr/share/maven/conf/是修改镜像中maven的配置，指向自己的maven库。

下载tomcat

wget http://archive.apache.org/dist/tomcat/tomcat-8/v8.5.5/bin/apache-tomcat-8.5.5.tar.gz

解压到tomcat-svn-catalog目录下的tomcat8文件夹下。

修改s2i/bin/assemble脚本（负责源代码的编译、构建以及构建产出物的部署）

#!/bin/bash -e## S2I assemble script for the 'nico-tomcat' image.# The 'assemble' script builds your application source ready to run.## For more information refer to the documentation:#       https://github.com/openshift/source-to-image/blob/master/docs/builder_image.md## Restore artifacts from the previous build (if they exist).#if [ "$1" = "-h" ]; then        # If the 'nico-tomcat' assemble script is executed with '-h' flag,        # print the usage.        exec /usr/libexec/s2i/usagefi# Restore artifacts from the previous build (if they exist).#if [ "$(ls /tmp/artifacts/ 2>/dev/null)" ]; then  echo "---> Restoring build artifacts"  mv /tmp/artifacts/. ./fiecho "---> Installing application source"WORK_DIR=/tmp/src;cd $WORK_DIR;if [ ! -z ${SVN_URI} ] ; then  echo "Fetching source from Subversion repository ${SVN_URI}"  svn co ${SVN_URI} --username=${SVN_USERNAME} --password=${SVN_PASSWORD} --no-auth-cache  export SRC_DIR=`basename $SVN_URI`  echo "Finished fetching source from Subversion repository ${SVN_URI}"  cd $WORK_DIR/$SRC_DIR/  mvn package -Dmaven.test.skip=true;else  echo "SVN_URI not set, skip Subverion source download";fifind /tmp/src/ -name '*.war'|xargs -i mv -v {} /opt/app-root/tomcat8/webapps/ROOT.warecho "---> Building application from source"

文件中下面这句就是根据用户输入的svn路径、账号、密码下载代码。

 svn co ${SVN_URI} --username=${SVN_USERNAME} --password=${SVN_PASSWORD} --no-auth-cache

编辑s2i/bin/run脚本（S2I流程生成的最终镜像将以这个脚本作为容器的启动命令）。

脚本内容为启动tomcat。

#!/bin/bash -e## S2I run script for the 'nico-tomcat' image.# The run script executes the server that runs your application.## For more information see the documentation:#       https://github.com/openshift/source-to-image/blob/master/docs/builder_image.md#exec /opt/app-root/tomcat8/bin/catalina.sh run

构建镜像并推送到自己的镜像仓库

在tomcat-svn-catalog目录下执行make。得到docker镜像后修改tag推送到镜像仓库。

在master节点上创建openshift-tomcat8-svn-is.json文件

{  "kind": "ImageStreamList",  "apiVersion": "v1",  "metadata": {},  "items": [    {      "kind": "ImageStream",      "apiVersion": "v1",      "metadata": {        "name": "openshift-tomcat8-svn",        "annotations": {"openshift.io/image.insecureRepository": "true"},        "creationTimestamp": null      },      "spec": {        "dockerImageRepository": "master.example.com:5000/openshift-tomcat8-svn",        "tags": [          {            "name": "latest"          },          {            "name": "2.0",            "annotations": {              "description": "Run JavaEE WAR applications",              "iconClass": "icon-ruby",              "tags": "builder,tomcat,java,war",              "supports": "java",              "version": "1.0"            },            "from": {              "kind": "ImageStreamTag",              "name": "latest"            }          }        ]      }    }  ]}

集群管理员账号执行命令。

oc create -n openshift -f openshift-tomcat8-svn-is.json

在master节点上创建openshift-tomcat8-svn-removegit-template.json文件

{    "kind": "Template",    "apiVersion": "v1",    "metadata": {        "annotations": {            "iconClass" : "icon-tomcat",            "description": "Application template for JavaEE WAR deployment with Tomcat 8."        },        "name": "openshift-tomcat8-svn-removegit"    },    "labels": {        "template": "openshift-tomcat8-svn-removegit"    },    "parameters": [        {            "description": "Tomcat 8.5.5",            "name": "IMG_VERSION",            "displayName":"Image Version",            "value": "latest",            "required": true        },        {            "description": "The name for the application.",            "name": "APPLICATION_NAME",            "displayName":"Application Name",            "value": "",            "required": true        },        {            "description": "Custom hostname for service routes.  Leave blank for default hostname, e.g.: <application-name>.<project>.<default-domain-suffix>",            "name": "APPLICATION_HOSTNAME",            "displayName":"Application Hostname",            "value": ""        },        {            "description": "Subversion source URI for application",            "name": "SVN_URI",            "displayName":"Subversion source URI",            "value": "",            "required": true        },        {            "description": "Subversion Username",            "name": "SVN_USERNAME",            "displayName":"Subversion Username",            "value": "",            "required": true        },        {            "description": "Subversion Password",            "name": "SVN_PASSWORD",            "displayName":"Subversion Password",            "value": "",            "required": true        }    ],    "objects": [        {            "kind": "Service",            "apiVersion": "v1",            "spec": {                "ports": [                    {                        "port": 8080,                        "targetPort": 8080                    }                ],                "selector": {                    "deploymentConfig": "${APPLICATION_NAME}"                }            },            "metadata": {                "name": "${APPLICATION_NAME}",                "labels": {                    "application": "${APPLICATION_NAME}"                },                "annotations": {                    "description": "The web server's http port."                }            }        },        {            "kind": "Route",            "apiVersion": "v1",            "id": "${APPLICATION_NAME}-http-route",            "metadata": {                "name": "${APPLICATION_NAME}-http-route",                "labels": {                    "application": "${APPLICATION_NAME}"                },                "annotations": {                    "description": "Route for application's http service."                }            },            "spec": {                "host": "${APPLICATION_HOSTNAME}",                "to": {                    "name": "${APPLICATION_NAME}"                }            }        },        {            "kind": "ImageStream",            "apiVersion": "v1",            "metadata": {                "name": "${APPLICATION_NAME}",                "labels": {                    "application": "${APPLICATION_NAME}"                }            }        },        {            "kind": "BuildConfig",            "apiVersion": "v1",            "metadata": {                "name": "${APPLICATION_NAME}",                "labels": {                    "application": "${APPLICATION_NAME}"                }            },            "spec": {                "strategy": {                    "type": "Source",                    "sourceStrategy": {                        "from": {                            "kind": "ImageStreamTag",                            "namespace": "openshift",                            "name": "openshift-tomcat8-svn:latest"                        },                        "env": [                                    {                                        "name": "SVN_URI",                                        "value": "${SVN_URI}"                                    },                                    {                                        "name": "SVN_USERNAME",                                        "value": "${SVN_USERNAME}"                                    },                                    {                                        "name": "SVN_PASSWORD",                                        "value": "${SVN_PASSWORD}"                                    }                       ]                    }                },                "output": {                    "to": {                        "kind": "ImageStreamTag",                        "name": "${APPLICATION_NAME}:latest"                    }                },                "triggers": [                    {                        "type": "GitHub",                        "github": {                            "secret": "${GITHUB_TRIGGER_SECRET}"                        }                    },                    {                        "type": "Generic",                        "generic": {                            "secret": "${GENERIC_TRIGGER_SECRET}"                        }                    },                    {                        "type": "ImageChange",                        "imageChange": {}                    }                ]            }        },        {            "kind": "DeploymentConfig",            "apiVersion": "v1",            "metadata": {                "name": "${APPLICATION_NAME}",                "labels": {                    "application": "${APPLICATION_NAME}"                }            },            "spec": {                "strategy": {                    "type": "Recreate"                },                "triggers": [                    {                        "type": "ImageChange",                        "imageChangeParams": {                            "automatic": true,                            "containerNames": [                                "${APPLICATION_NAME}"                            ],                            "from": {                                "kind": "ImageStream",                                "name": "${APPLICATION_NAME}"                            }                        }                    }                ],                "replicas": 1,                "selector": {                    "deploymentConfig": "${APPLICATION_NAME}"                },                "template": {                    "metadata": {                        "name": "${APPLICATION_NAME}",                        "labels": {                            "deploymentConfig": "${APPLICATION_NAME}",                            "application": "${APPLICATION_NAME}"                        }                    },                    "spec": {                        "containers": [                            {                                "name": "${APPLICATION_NAME}",                                "image": "${APPLICATION_NAME}",                                "imagePullPolicy": "Always",                                "readinessProbe": {                                    "exec": {                                        "command": [                                            "/bin/bash",                                            "-c",                                            "curl http://localhost:8080"                                        ]                                    }                                },                                "ports": [                                    {                                        "name": "http",                                        "containerPort": 8080,                                        "protocol": "TCP"                                    }                                ],                                "env": [                                    {                                        "name": "SVN_URI",                                        "value": "${SVN_URI}"                                    }                                ]                            }                        ]                    }                }            }        }    ]}

集群管理员账号执行命令。

oc create -n openshift -f openshift-tomcat8-svn-removegit-template.json

验证

可从界面输入SVN的地址、账号、密码完成创建。

最终完成了从SVN拉取代码、编译、部署等一系列流程。

已知缺陷

1.SVN密码现在是明文的形式
2.template中暂未提供对build config、deploy config等的配置，界面还较为简单。

结语

本篇博客主要记录了工作过程，没有特别具体，但基本覆盖了所有过程。

仅供参考。