Checking Oracle Database Connection from Java

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import java.sql.Connection;
import java.sql.Date;
import java.sql.DriverManager;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;

public class OracleSample {

    public static final String DBURL = "jdbc:oracl:thin:@***.***.***.***:1521:oracledatabase";
    public static final String DBUSER = "username";
    public static final String DBPASS = "Oracle8521";

    public static void main(String[] args) throws SQLException {
     
        // Load Oracle JDBC Driver
        DriverManager.registerDriver(new oracle.jdbc.OracleDriver());
     
        // Connect to Oracle Database
        Connection con = DriverManager.getConnection(DBURL, DBUSER, DBPASS);

        Statement statement = con.createStatement();

        // Execute a SELECT query on Oracle Dummy DUAL Table. Useful for retrieving system values
        // Enables us to retrieve values as if querying from a table
        ResultSet rs = statement.executeQuery("SELECT SYSDATE FROM DUAL");
     
     
        if (rs.next()) {
            Date currentDate = rs.getDate(1); // get first column returned
            System.out.println("Current Date from Oracle is : "+currentDate);
        }
        rs.close();
        statement.close();
        con.close();
    }
}
===================

>># javac -cp "./ojdbc7.jar:." OracleSample.java
>># java -cp "./ojdbc7.jar:." OracleSample
Current Date from Oracle is : 2017-02-09

Kibana Authentication with Nginx on Centos

Kibana doesn’t support authentication or restricting access to dashboards by default.We can restrict access to Kibana 4 using nginx as a proxy in front of Kibana.

Install nginx server:

To install Nginx using yum we need to include the Nginx repository, install the Nginx repository using,

1	rpm -Uvh http://nginx.org/packages/centos/7/noarch/RPMS/nginx-release-centos-7-0.el7.ngx.noarch.rpm

Install Nginx and httpd-tools by issuing the following command,

1	yum -y install nginx httpd-tools

Create a password file for basic authentication of http users, this is to enable the password protected access to kibana portal. Replace “admin” with your own user name

1	htpasswd -c /etc/nginx/conf.d/kibana.htpasswd adin

Configure Nginx:

Create a confiiguration file with the name kibana.conf in /etc/nginx/conf.d directory

1	vi /etc/nginx/conf.d/kibana.conf

Place the following content to the kibana.conf file, assuming that both kibana and Nginx are installed on same server


server {
listen *:8080;
server_name 192.168.01;
access_log /var/log/nginx/kibana-access.log;
error_log /var/log/nginx/kibana-error.log;

location / {
auth_basic "Restricted Access";
auth_basic_user_file /etc/nginx/conf.d/kibana.htpasswd;
proxy_pass http://192.168.01:5601;
#proxy_connect_timeout 150;
#proxy_send_timeout 100;
#proxy_read_timeout 100;
}
}

Restart nginx server:

1	sudo service nginx restart

Go to the URL : http://192,168.01:8080, we should get an authentication screen as below on successful setup,

If nothing is showing up check the logs and see whether you have encountered an error as below,

2015/08/11 22:31:13 [crit] 80274#0: *3 connect() to 192.168.1.5:5601 failed (13: Permission denied) while connecting to upstream, client: 10.200.100.29, server: 10.242.126.73, request: "GET / HTTP/1.1", upstream: "http://192.168.1.5:5601/", host: "192.168.1.5:8080"

Error Resolution:
This is happening because we have selinux enabled on our machine.

Disable the selinux by running the command

1	sudo setsebool -P httpd_can_network_connect 1

Restart nginx:

1	sudo service nginx restart

Aws Volume tagging Script.

Following Script will give the aws cli command to tag the volumes with tags associated to its instance.

Prerequisite
1. All instance are tagged properly
2. Aws Cli is installed and Configured properly
3. Configure the Aws Cli output to Json
4. Create the File Full_Json_Instances.json with output of describe-instances

===================
#/bin/python
import json

def fun_Instance_Volume_Tagging(Instance_ID, Instance):
    for Volumes in Instance["Instances"][0]["BlockDeviceMappings"]:
        VOL_ID = Volumes["Ebs"]["VolumeId"]
        for Tags in Instance["Instances"][0]["Tags"]:
            TAG_KEY = Tags["Key"]
            TAG_VALUE = Tags["Value"]
            print "aws ec2 create-tags --resources " + VOL_ID + " --tags Key=" + TAG_KEY + ",Value=" + TAG_VALUE +""

with open("Full_Json_Instances.json") as json_file:
    json_data = json.load(json_file)
    for Instances in json_data["Reservations"]:
        Instance_ID = Instances["Instances"][0]["InstanceId"];
        fun_Instance_Volume_Tagging(Instance_ID, Instances)
====================