Monthly Archives: December 2016

Read a file from resources folder in Java

String fileName="build.txt";
ClassLoader classLoader = getClass().getClassLoader();
InputStream in = classLoader.getResourceAsStream(fileName);
BufferedReader bufferedReader=new BufferedReader(new InputStreamReader(in));
String buildNumberStr= bufferedReader.readLine();
bufferedReader.close();
result=buildNumberStr;

References
https://www.mkyong.com/java/java-read-a-file-from-resources-folder/

RealVNC on Linux

Installed systemd unit for VNC Server in Service Mode daemon
Start or stop the service with:
systemctl (start|stop) vncserver-x11-serviced.service
Mark or unmark the service to be started at boot time with:
systemctl (enable|disable) vncserver-x11-serviced.service

Installed systemd unit for VNC Server in Virtual Mode daemon
Start or stop the service with:
systemctl (start|stop) vncserver-virtuald.service
Mark or unmark the service to be started at boot time with:
systemctl (enable|disable) vncserver-virtuald.service

Use Spring Boot behind Apache front-end proxy server

Apache

a2enmod proxy
a2enmod proxy_http
a2enmod proxy_ajp
a2enmod rewrite
a2enmod deflate
a2enmod headers
a2enmod proxy_balancer
a2enmod proxy_connect
a2enmod proxy_html
sudo a2enmod remoteip
sudo service apache2 restart
<VirtualHost *:80>
  ServerName iterator.ir

  ProxyRequests Off
  ProxyPreserveHost On
  RemoteIPHeader X-Forwarded-For
  <Proxy *>
    Order deny,allow
    Allow from all
  </Proxy>

  ProxyPass / http://localhost:13602/
  ProxyPassReverse / http://localhost:13602/
</VirtualHost>
<VirtualHost *:443>
	SSLEngine on
	RewriteEngine on
	SSLCertificateKeyFile /etc/letsencrypt/live/lastlab.pupli.net/privkey.pem
	SSLCertificateFile /etc/letsencrypt/live/lastlab.pupli.net/cert.pem
	SSLCertificateChainFile /etc/letsencrypt/live/lastlab.pupli.net/chain.pem
	ServerName lastlab.pupli.net
 
	ProxyRequests Off
	ProxyPreserveHost On
	RemoteIPHeader X-Forwarded-For
	<Proxy *>
		Order deny,allow
		Allow from all
	</Proxy>
 
	ProxyPass / http://localhost:14001/
	ProxyPassReverse / http://localhost:14001/
</VirtualHost>

Spring Boot
set server.use-forward-headers to server.use-forward-headers in Spring Boot application.properties

Java

String ipAddress = request.getHeader("X-FORWARDED-FOR");
if (ipAddress == null) {
	   ipAddress = request.getRemoteAddr();
}

References
https://docs.spring.io/spring-boot/docs/current/reference/html/howto-embedded-servlet-containers.html#howto-use-tomcat-behind-a-proxy-server
https://www.mkyong.com/java/how-to-get-client-ip-address-in-java/
http://serverfault.com/questions/130925/passing-ip-address-with-mod-proxy
https://www.leaseweb.com/labs/2014/12/tutorial-apache-2-4-transparent-reverse-proxy/
http://www.thegeekstuff.com/2011/07/Apache-Virtual-Host/
https://devops.profitbricks.com/tutorials/configure-apache-as-a-reverse-proxy-using-mod_proxy-on-ubuntu/
https://www.digitalocean.com/community/tutorials/how-to-use-apache-http-server-as-reverse-proxy-using-mod_proxy-extension

Installing Spring Boot applications

apply plugin: 'org.springframework.boot'

springBoot {
    executable = true
}

Installation as a systemd service

/etc/systemd/system
[Unit]
Description=erpserver

[Service]
User=root
ExecStart=/var/erpserver/erpserver-1.0.0.jar
SuccessExitStatus=143

[Install]
WantedBy=multi-user.target
service erpserver start

Keywords
deploy , jar

References
http://docs.spring.io/spring-boot/docs/current/reference/html/deployment-install.html

Using Virtual_host and mod_proxy together in Apache

first configure DNS :

dns2

a2enmod proxy_http
nano /etc/apache2/apache2.conf
<VirtualHost *:80>
  ServerName public.server.name

  ProxyRequests Off
  ProxyPreserveHost On

  <Proxy *>
    Order deny,allow
    Allow from all
  </Proxy>

  ProxyPass / http://localhost:8080/
  ProxyPassReverse / http://localhost:8080/
</VirtualHost>

Keywords
apache , virtual host , VirtualHost , reverse , proxy

References
http://stackoverflow.com/questions/956361/apache-tomcat-using-mod-proxy-instead-of-ajp
https://httpd.apache.org/docs/2.4/vhosts/examples.html
http://askubuntu.com/questions/58179/install-mod-proxy-to-get-proxypass-to-work
http://www.thegeekstuff.com/2011/07/Apache-Virtual-Host/

How to configure proxy authentication to work with Ubuntu Software Center

Go to /etc/apt. Create the file apt.conf if you don’t have it there. Write the following lines there.

Acquire::http::proxy "http://username:password@proxyserver:port/";
Acquire::https::proxy "https://username:password@proxyserver:port/";
Acquire::socks::proxy "socks://username:password@proxyserver:port/";
Acquire::ftp::proxy "ftp://username:password@proxyserver:port/";

Save it. You are done.

Keywords
apt , ubuntu , proxy

References
http://askubuntu.com/questions/77449/how-to-configure-proxy-authentication-to-work-with-ubuntu-software-center