OpenShift實戰(七)：OpenShift定制鏡像S2I

1、基礎鏡像制作

　　由於公司的程序是Java開發，上線發布使用的是maven，如果使用openshift自帶的S2I，每次都會全量拉取代碼(代碼比較多，每次全量拉太慢)，然后每次打包都會再一次下載maven插件，官方也有save-artifacts的方法，貌似是保存編譯的產物，但是我沒有研究成功，所以就用了制作鏡像的笨方法進行一些基礎環境的搭建。

[root@master1 dockerfile]# cat Dockerfile 
# There is a base Dockerfile
# Version 1.0
# Auther is Dukuan

FROM centos:6

MAINTAINER Du Kuan
ADD ./apache-maven-3.0.5.tar.gz /usr/local/
ADD ./jdk1.8.0_144.tar.gz /usr/local
ADD ./apache-tomcat-8.5.23.tar.gz /tmp
ADD ./key.tar.gz /tmp
ADD ./data.tar.gz /
RUN  useradd -m tomcat -u 1001 && mkdir /home/tomcat/{.ssh,git} && mkdir /data01 && chown -R tomcat.tomcat /data* && mv /tmp/apache-tomcat-8.5.23 /home/tomcat/ && mv /tmp/id_dsa /home/tomcat/.ssh && mv /tmp/known_hosts /home/tomcat/.ssh  && yum install git -y  && chown -R tomcat.tomcat /home/tomcat/ &&  chmod -R a+rw /home/tomcat &&  chmod a+rwx /home/tomcat/apache-tomcat-8.5.23/* && chmod +x /home/tomcat/apache-tomcat-8.5.23/bin/*.sh && yum clean all && chmod 600 /home/tomcat/.ssh/id_dsa && su - tomcat -c "cd /home/tomcat/git && git clone git@192.168.1.212:server/walrus-platform.git"  
ENV JAVA_HOME=/usr/local/jdk1.8.0_144
ENV PATH=/usr/local/apache-maven-3.0.5/bin:${JAVA_HOME}/bin:${PATH}
USER 1001
# WORKDIR /home/tomcat/git
# RUN git clone git@192.168.1.212:server/walrus-platform.git 
WORKDIR /home/tomcat/git/walrus-platform
RUN git checkout develop-feature-4.1-optimiz && mvn compile package -Dmaven.test.skip=true -Ptesting && mvn clean
USER 0

　　上面的Dockerfile包括拉取全量代碼到Tomcat家目錄下(公司使用的都是Tomcat用戶)，然后進行Maven打包，下載對應的插件，最后在clean，然后生成的鏡像作為S2I的基礎鏡像。

　　執行構建

docker build -t xxx:xxx .

 

2、安裝S2I

　　安裝比較簡單，在https://github.com/openshift/source-to-image/releases下載最新版S2I。

tar xf source-to-image-v1.1.9a-40ad911d-linux-amd64.tar.gz -C /usr/bin/

　　檢驗安裝

[root@master1 bin]# s2i version
s2i v1.1.9a
[root@master1 bin]#

 

3、創建S2I

　　創建一個名為tomcat-s2i的S2I Builder鏡像。第三個參數為工作目錄的名稱。

[root@openshift-master1]s2i create tomcat-s2i tomcat-s2i
[root@openshift-master1 tomcat-s2i]# ls
Dockerfile  Makefile  README.md  s2i  test

 

4、修改S2I的Dockerfile

　　由於已經制作了基礎鏡像，所以S2I的Dockerfile只需要將FROM改為上述創建的鏡像即可。

# walrus-platform
FROM xxx:xxx
LABEL io.openshift.s2i.scripts-url=image:///usr/libexec/s2i io.k8s.description="Tomcat S2I Builder" io.k8s.display-name="tomcat s2i builder 1.0" io.openshift.expose-services="8080:http"  io.openshift.tags="builder, tomcat"
COPY ./s2i/bin/ /usr/libexec/s2i
RUN chown -R tomcat.tomcat /usr/libexec/s2i && chmod +x /usr/libexec/s2i/bin/*
USER 1001
# 端口
EXPOSE 8080
ENTRYPOINT []
CMD ["usage"]

 

5、修改S2I的assemble

　　assemble主要寫一些編譯的參數或命令，主要用於寫重構的步驟，由於上述采用的定制的基礎鏡像，並將全部代碼放到了Tomcat下，所以直接在Tomcat的家目錄下進行操作，忽略openshift自帶的build，相當於欺騙了openshift，用於避免每次全量拉取代碼和每次重構下載插件。

#!/bin/bash -e
#
# S2I assemble script for the 'walrus' image.
# The 'assemble' script builds your application source so that it is ready to run.
#
# For more information refer to the documentation:
#    https://github.com/openshift/source-to-image/blob/master/docs/builder_image.md
#

# If the 'walrus' assemble script is executed with the '-h' flag, print the usage.
if [[ "$1" == "-h" ]]; then
    exec /usr/libexec/s2i/usage
fi

# Restore artifacts from the previous build (if they exist).
#
if [ "$(ls /tmp/artifacts/ 2>/dev/null)" ]; then
  echo "---> Restoring build artifacts..."
  mv /tmp/artifacts/. ./
fi

echo "---> Installing application source..."
echo "+++++++++++++++++++++++${POM_ENV}++++++++++++++"
# WORKDIR on xxx now
mvn compile package -Dmaven.test.skip=true -P${POM_ENV}
find . -type f -name "*${WAR_NAME}*" | xargs -i cp {} /home/tomcat/apache-tomcat-8.5.23/webapps
mvn clean
rm -rf ./*
echo "---> Building application from source..."
# TODO: Add build steps for your application, eg npm install, bundle install, pip install, etc.

 

6、修改S2I的run

　　此文件主要寫容器啟動后需要執行的命令，我公司的就是啟動Tomcat。

#!/bin/bash -e
#
# S2I run script for the 'walrus-platform' 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
#

/home/tomcat/apache-tomcat-8.5.23/bin/startup.sh
tail -f /home/tomcat/apache-tomcat-8.5.23/logs/catalina.out

 

7、執行構建

　　通過執行make進行構建，通過docker images查看生成的鏡像，鏡像名稱即為創建S2I寫的名字

 

8、導入S2I

　　由於生成的S2I在本地，它需要能被openshift的所有節點都能下載，所以講它直接push到自己的私有倉庫中，如果沒有私有倉庫，可以使用docker-registry搭建一個簡易的。

yum install docker-registry
systemctl start docker-distribution.service 
systemctl enable docker-distribution.service
修改所有節點Docker配置
[root@master1]# cat /etc/sysconfig/docker
# /etc/sysconfig/docker

# Modify these options if you want to change the way the docker daemon runs
#OPTIONS='--selinux-enabled --log-driver=journald --signature-verification=false'
OPTIONS=' --selinux-enabled  --log-driver=journald  --registry-mirror=https://docker.mirrors.ustc.edu.cn --insecure-registry=172.30.0.0/16 --insecure-registry 192.168.10.110:5000'

　　其中--insecure-registry 192.168.10.110:5000為自己的私有倉庫。

　　添加tag並push

docker tag walrus-platform 192.168.10.110:5000/xxx
docker push 192.168.10.110:5000/xxx

　　 導入鏡像到IS

[root@master1 walrus-platform]# oc project openshift
Now using project "openshift" on server "https://master1.xxx.net:8443".
[root@master1 walrus-platform]# oc import-image 192.168.10.110:5000/walrus-platform -n openshift --confirm --insecure
The import completed successfully.

Name:            walrus-platform
Namespace:        openshift
Created:        Less than a second ago
Labels:            <none>
Annotations:        openshift.io/image.dockerRepositoryCheck=2018-03-19T07:14:21Z
Docker Pull Spec:    docker-registry.default.svc:5000/openshift/walrus-platform
Image Lookup:        local=false
Unique Images:        1
Tags:            1

latest
  tagged from 192.168.10.110:5000/walrus-platform
    will use insecure HTTPS or HTTP connections

  * 192.168.10.110:5000/walrus-platform@sha256:0b963c801da6e40c3a201449c504ab8f605ea8db6054dea6873ac6e80b3c718d
      Less than a second ago

Image Name:    walrus-platform:latest
Docker Image:    192.168.10.110:5000/walrus-platform@sha256:0b963c801da6e40c3a201449c504ab8f605ea8db6054dea6873ac6e80b3c718d
Name:        sha256:0b963c801da6e40c3a201449c504ab8f605ea8db6054dea6873ac6e80b3c718d
Created:    Less than a second ago
Image Size:    625 MB (first layer 1.188 kB, last binary layer 70.08 MB)
Image Created:    19 minutes ago
Author:        <none>
Arch:        amd64
Command:    usage
Working Dir:    /home/tomcat/git/walrus-platform
User:        1001
Exposes Ports:    8080/tcp
Docker Labels:    build-date=20180302
        io.k8s.description=Tomcat S2I Builder
        io.k8s.display-name=tomcat s2i builder 1.0
        io.openshift.expose-services=8080:http
        io.openshift.s2i.scripts-url=image:///usr/libexec/s2i
        io.openshift.tags=builder, tomcat
        license=GPLv2
        name=CentOS Base Image
        vendor=CentOS
Environment:    PATH=/usr/local/apache-maven-3.0.5/bin:/usr/local/jdk1.8.0_144/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
        JAVA_HOME=/usr/local/jdk1.8.0_144

 

9、修改信息

　　修改注釋讓openshift識別出這個鏡像：

oc edit is/walrus-platform -n openshift

　　修改如下：

　　

 

10、查看鏡像

　　登錄控制台查看：