這篇要介紹在 OpenSUSE 上安裝Nginx、Java、Tomcat，並將前端畫面放置在Nginx，後端放置在Tomcat中，當中碰到小卡關的地方

安裝軟體時，會有儲存庫缺失問題，需要加入儲存庫
Tomcat因為Java安裝路徑不對，無法啟動
同樣的安裝指令安裝起來的Java版本不同
Nginx如何設置才讀到到畫面
前端畫面call後端發生CORS問題

安裝軟體時，會有儲存庫缺失問題，需要加入儲存庫

SUSE 有專用安裝軟體的套件，zypper & Yast，這裡只使用zypper，zypper安裝指令為 (以Java為例) zypper install java-1_8_0-openjdk

在安裝前可以先查詢，指令為 zypper search java，搜尋後發現沒有java，這是因為我們的儲存庫 repository 中沒有支援java，我們只要加入即可

1	zypper addrepo https://download.opensuse.org/repositories/Java:Factory/openSUSE_Leap_15.1/Java:Factory.repo

java repository

此時使用 zypper search java ，就可以看到java版本供選擇，加入儲存庫後要安裝時又發生一個問題，說有一個giflib套件沒有加入，再加入即可

1	zypper addrepo https://download.opensuse.org/repositories/openSUSE:Leap:15.1/standard/openSUSE:Leap:15.1.repo

giflib repository

1	zypper install java-1_8_0-openjdk

Tomcat因為Java安裝路徑不對，無法啟動

tomcat(source code install, download from http://ftp.mirror.tw/pub/apache/tomcat/tomcat-9/v9.0.36/bin/apache-tomcat-9.0.36.tar.gz)

1	sudo wget http://ftp.mirror.tw/pub/apache/tomcat/tomcat-9/v9.0.36/bin/apache-tomcat-9.0.36.tar.gz

將壓縮檔丟到/opt
解壓縮

1	sudo tar xvf /opt/apache-tomcat-9* -C /opt/tomcat --strip-components=1

更改權限

1	sudo useradd -M -s /bin/nologin -d /opt/tomcat tomcat

加上log

1	sudo mkdir /opt/tomcat/Log

改變所屬群組

1	sudo chown -R tomcat:users /opt/tomcat

編輯tomcat.service檔

1	vi /etc/systemd/system/tomcat.service

JAVA_HOME要符合java安裝路徑

[Unit]
Description=Apache Tomcat Web Application Container
After=network.target
 
[Service]
Type=forking
 
Environment=JAVA_HOME=/usr/lib64/jvm/jre-1.8.0-openjdk/bin
Environment=CATALINA_PID=/opt/tomcat/temp/tomcat.pid
Environment=CATALINA_HOME=/opt/tomcat
Environment=CATALINA_BASE=/opt/tomcat
Environment='CATALINA_OPTS=-Xms512M -Xmx8192M -server -XX:+UseParallelGC'
Environment='JAVA_OPTS=-Djava.awt.headless=true -Djava.security.egd=file:/dev/./urandom -Dfile.encoding=UTF8'
 
ExecStart=/opt/tomcat/bin/startup.sh
ExecStop=/opt/tomcat/bin/shutdown.sh
 
User=tomcat
Group=users
RestartSec=10
Restart=always
 
[Install]
WantedBy=multi-user.target

設定開機啟動

1	systemctl enable tomcat

重讀service腳

1	systemctl daemon-reload

啟動tomcat

1	systemctl start tomcat

確認tomcat

1	systemctl status tomcat

同樣的安裝指令安裝起來的Java版本不同

去客戶那邊安裝時，測試環境我安裝起來是1.8.0_252，客戶自行安裝的java版本卻變成1.8.0_202，猜測可能是OpenSuse跟Suse的repository不一樣，故採用直接手動安裝的方式

使用AdoptOpenJDK
選擇欲安裝的版本與系統，把.tar.gz檔案載下來
scp 方式丟上遠端server
cp 到預安裝的路徑，並解壓縮

1	$ sudo tar xvf /usr/lib64/java/OpenJDK8U-jre_x64_linux_hotspot_8u252b09.tar.gz -C /usr/lib64/java --strip-components=1

設定環境變數

$ sudo vim /etc/profile
#最後一行加入
#set java info
export JAVA_HOME=/usr/lib64/java
export PATH="$JAVA_HOME/bin:$PATH"

6.reload /etc/profile

1	$ . /etc/profile

檢查java版本

$ java -version
openjdk version "1.8.0_252"
OpenJDK Runtime Environment (AdoptOpenJDK)(build 1.8.0_252-b09)
OpenJDK 64-Bit Server VM (AdoptOpenJDK)(build 25.252-b09, mixed mode)

將Tomcat中的java路徑更改後暫停再重啟，確認CGroup的啟動路徑已經改為設定的環境變數

$ sudo vim /etc/systemd/system/tomcat.service
$ sudo systemctl enable tomcat
$ sudo systemctl daemon-reload
$ sudo systemctl start tomcat
$ sudo systemctl status tomcat
tomcat.service - Apache Tomcat Web Application Container
   Loaded: loaded (/etc/systemd/system/tomcat.service; enabled; vendor preset: disabled)
   Active: active (running) since 三 2020-06-17 13:58:34 CST; 23min ago
  Process: 14578 ExecStop=/opt/tomcat/bin/shutdown.sh (code=exited, status=0/SUCCESS)
  Process: 14628 ExecStart=/opt/tomcat/bin/startup.sh (code=exited, status=0/SUCCESS)
 Main PID: 14635 (java)
    Tasks: 31 (limit: 512)
   CGroup: /system.slice/tomcat.service
           └─14635 /usr/lib64/java/bin/java -Djava.util.logging.config.file=/opt/tomcat/conf/logging.properties -Dja...

 6月 17 13:58:34 linux-g5k0 systemd[1]: Starting Apache Tomcat Web Application Container...
 6月 17 13:58:34 linux-g5k0 startup.sh[14628]: Tomcat started.
 6月 17 13:58:34 linux-g5k0 systemd[1]: Started Apache Tomcat Web Application Container.

Nginx如何設置才讀到到畫面

加入nginx repository

1	sudo zypper addrepo -G -t yum -c 'http://nginx.org/packages/sles/12' nginx

更新 repository

1	zypper refresh

安裝 nginx

1	zypper install nginx

編輯default.conf檔

cd /etc/nginx/conf.d/
#備份default.conf
cp /etc/nginx/conf.d/default.conf /etc/nginx/conf.d/default.conf_bk
#編輯default.conf
vi /etc/nginx/conf.d/default.conf

server {
        location /yourPath {
            root   /usr/share/nginx;
            index  index.html index.htm;
            try_files $uri $uri/ /yourPath/index.html;
    }
}

前端畫面call後端發生CORS問題

call後端一直call不到，browser一直顯示

1	Request header field Access-Control-Allow-Headers is not allowed by Access-Control-Allow-Headers in preflight response

而且看了NetWork的地方同一request竟然call了兩次，一次是以http Method Option去call，一次是以原本的post去call，但是請求失敗，上網了解後原來是因為某些條件觸發了預檢請求(Option)，先確認說server可以接受什麼樣的request，所以去檢查是不是有沒有對起來的地方，發現我server接受的Access-Control-Request-Headers: 沒有authorization，於是我在後端程式加入authorization就好了

Access-Control-Allow-Headers: X-requested-with, Content-Type
Access-Control-Allow-Methods: POST, GET, PUT, OPTIONS, DELETE
Access-Control-Allow-Origin: *
Access-Control-Max-Age: 3600
Allow: GET, HEAD, POST, PUT, DELETE, OPTIONS, PATCH
Connection: keep-alive
Content-Length: 0
Date: Fri, 12 Jun 2020 02:37:43 GMT
Keep-Alive: timeout=20

Request Headers view source
Accept: */*
Accept-Encoding: gzip, deflate
Accept-Language: zh-TW, zh; q=0.9,en-US; q=0.8,en; q=0.7, zh-CN; q=0.6 
Access-Control-Request-Headers: authorization, content-type

public class CORSFilter implements Filter {

    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        HttpServletResponse response = (HttpServletResponse) res;
        HttpServletRequest request = (HttpServletRequest) req;
        request.setCharacterEncoding("UTF-8");
        response.setHeader("Access-Control-Allow-Origin", "*");
        response.setHeader("Access-Control-Allow-Methods", "POST, GET, PUT, OPTIONS, DELETE");
        response.setHeader("Access-Control-Max-Age", "3600");
        response.setHeader("Access-Control-Allow-Headers", "X-requested-with, Content-Type, authorization");
        chain.doFilter(req, res);
    }

    public void init(FilterConfig filterConfig) {}

    public void destroy() {}

}

跨來源資源共用（CORS）

Catherine's blog

OpenSUSE-install