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Showing posts from July, 2017

Installation of Linux distros on Windows 10

Starting with the Windows 10 Fall Creators Update, Microsoft is making some Linux distros, including Ubuntu, SUSE Linux Enterprise Server 12, and OpenSUSE Leap 42 available in the Windows Store. Additionally, it's no longer a prerequisite to enable Developer mode, which makes the installation of Linux distros a lot easier.

Google now allows G Suite users to access coworkers' real-time free/busy information through both Google Calendar's Find a Time feature and Microsoft Outlook's Scheduling Assistant interchangeably.

G Suite admins can enable the new Calendar Interop management feature through the Settings for Calendar option in the admin console. Admins will also be able to easily pinpoint issues with the setup via a troubleshooting tool, which will also provide suggestions for resolving those issues, and can track interoperability successes and failures for each user through logs Google has made available.
Amazon Polly is a service that turns text into lifelike speech. Amazon Polly includes dozens of lifelike voices and support for a variety of languages, so you can select the ideal voice and distribute your speech-enabled applications in many countries. With Amazon Polly, you just send the text you want converted into speech to the Amazon Polly API, and Amazon Polly immediately returns the audio stream to your application so you can play it directly or store it in a standard audio file format, such as MP3.

The @Model annotation

The @Model annotation does 2 things:

it makes the object @RequestScoped, instead of @Dependent
it gives the object an EL name So it's not intended to be used for entities, rather for things that contain application/business logic.

To ensure interoperability of Serializable across versions, consider adding an explicit serialVersionUID.

This class implements the Serializable interface, but does not define a serialVersionUID field.  A change as simple as adding a reference to a .class object will add synthetic fields to the class, which will unfortunately change the implicit serialVersionUID (e.g., adding a reference to String.class will generate a static field class$java$lang$String). Also, different source code to bytecode compilers may use different naming conventions for synthetic variables generated for references to class objects or inner classes. To ensure interoperability of Serializable across versions, consider adding an explicit serialVersionUID.

AWS Public Subnet vs Private Subnet

Public Subnet
If a subnet’s default traffic is routed to an Internet gateway, the subnet is known as a public subnet. For example, an instance launched in this subnet is publicly accessible if it has an Elastic IP address or a public IP address associated with it.
Private Subnet
If a subnet's default traffic is routed to an NAT instance/gateway or completely lacks a default route, the subnet is known as a private subnet. For example, an instance launched in this subnet is not publicly accessible even if it has an Elastic IP address or a public IP address associated with it.

How to Limit Access to Your Site Based on IP Address

You can limit access to your website so that only your IP address can access the site.  Here are the steps to do that.
Find out what your IP address is by visiting a file called .htaccess in your website root directory.Place the text below in the file and replace the marker with your IP address.order deny,allow deny from all allow from <your ip> That should block anyone who isn’t from your IP address from accessing your web applications. Test it by using FTP or SSH to change the IP slightly and you should lose access to the website. Make sure you aren’t using a web based file manager, or you will block yourself when you do this test.

This is very useful when setting up WordPress and anything else knowing that no one else can abuse your setup scripts. During the initial set up, it is very vulunable.

To remove the access control, simply delete the above lines from your .htaccess file and access for everyone else will be restored.

chrootkit is one of the best tools for keeping your system clean or knowing when it isn’t

chkrootkit is a tool to locally check for signs of a rootkit. It contains:
chkrootkit: shell script that checks system binaries for rootkit modification.ifpromisc.c: checks if the interface is in promiscuous mode.chklastlog.c: checks for lastlog deletions.chkwtmp.c: checks for wtmp deletions.check_wtmpx.c: checks for wtmpx deletions. (Solaris only)chkproc.c: checks for signs of LKM trojans.chkdirs.c: checks for signs of LKM trojans.strings.c: quick and dirty strings replacement.chkutmp.c: checks for utmp deletions.

How to Enable Glassfish SErver in Verbose Mode

To have the server logs and messages printed to System.out on your command prompt screen, you can start the server in verbose mode. This makes it easy to do simple debugging using print statements, without having to view the server.log file every time.

To start the server in verbose mode, use the ----verbose option as follows:
asadmin start-domain --verbose [domain-name]

How to Delete File Permanently in Linux

Normally, we use the rm command to delete files from a Linux system, however, these files do not completely get deleted, they are simply stored and hidden on the hard disk and can still be recovered these files in Linux and viewed by another person. To prevent this, we can use the shred command which overwrites the file content and optionally deletes the file as well.
$ shred -zvu tecmint.pdf The options used in the above command:
-z – adds a final overwrite with zeros to hide shredding.-u – helps to truncate and remove file after overwriting.-v – shows progress.

Wordpress Text-Editor JavaScript API

With the addition of TinyMCE to the text widget in 4.8 comes a new JavaScript API for instantiating the editor after page load. This can be used to add an editor instance to any text area, and customize it with buttons and functions. Great for plugin authors!

Shortcuts for Private Mode

To quickly open private browsing mode in popular browsers, use the following shortcuts: Firefox – Ctrl + Shift + PChrome [incognito] – Ctrl + Shift + NOpera - Ctrl + Shift + N

Alpine is a free software email client which is much more of a familiar interface if you are used to GUI email software like Thunderbird.

Alpine is a rewrite of the Pine Message System that adds support for Unicode and other features. Alpine is meant to be suitable for both inexperienced email users and the most demanding of power users. Alpine can be learned by exploration and the use of context-sensitive help. The user interface can be customized.

Enabling Single Sign-On Access to Amazon QuickSight Using SAML 2.0

Amazon QuickSight supports identity federation through Security Assertion Markup Language 2.0 (SAML 2.0) in both Standard and Enterprise editions. You can use an identity provider that supports SAML 2.0 to provide a simple on-boarding flow for your Amazon QuickSight users. Such identity providers include Microsoft Active Directory Federation Services, Ping One Federation Server, and Okta.

Microservice architecture

Microservice architecture is the hottest architectural style these days. It advocates to structure the application or system as a set of loosely coupled, ideally small, self-sufficient services which collaborate with each other.

Amazon Aurora

Amazon Aurora is a relational database engine that combines the speed and availability of commercial databases with the simplicity of open source databases, compatible with MySQL and PostgreSQL.


Gradle is build automation evolved. Gradle can automate the building, testing, publishing, deployment and more of software packages or other types of projects such as generated static websites, generated documentation or indeed anything else.

Gradle combines the power and flexibility of Ant with the dependency management and conventions of Maven into a more effective way to build. Powered by a Groovy DSL and packed with innovation, Gradle provides a declarative way to describe all kinds of builds through sensible defaults. Gradle is quickly becoming the build system of choice for many open source projects, leading edge enterprises and legacy automation challenges.

Data types of Custom Fields of objects

Summary of some common used supported data types of Custom Fields of objects:

Auto Number—a system-generated read-only sequence number, analogous to the SQL identity type. These fields can be used to provide a unique ID that is independent of the internal object ID. These fields are not used in creating object relationships.Checkbox—for representing Boolean data.Date or Date/Time—for representing dates or date and time combinations.Number—for representing real numbers, with optional decimal points.Email, Phone and URL—format-validated email, phone and URL string representations.Picklist and Multi-Select Picklists—represent values from a list.Text and Text Areas—for representing text of various lengths.Currency—a formatted number type, with optional multi-currency support.Formula—a read-only field holding data generated from a formula expression.Geolocation—allows you to identify locations by their latitude and longitude and calculate distances between locations.

Differences Between Lookup and Master-Detail Relationships in

Differences Between Lookup and Master-Detail Relationships:

There are fundamental differences between the two types of relationships in areas such as data deletion, sharing, and required fields in page layouts.

Master-detail relationships are typically used when there is a direct dependency between the two objects. These relationships have the following unique features.You can’t create a detail record without a master record.When you delete a master record, all its detail records are automatically deleted.The detail record inherits sharing rules from the master record.The number of master-detail relationships you can use are limited, depending on your edition and license.You can’t set profile object permissions for a detail record.Master-detail relationships are automatically included in report record types.

Lookup relationships are appropriate when a relationship between two objects is required in some cases, but not always. Typical scenarios for lookup relationships are:

To reference…

Email Feedback Forwarding Destination of Amazon SES

When you receive notifications by email, Amazon SES rewrites the From: header and sends the notification to you. The address to which Amazon SES forwards the notification depends on how you sent the original message. If you used the SMTP interface to send the message, then notifications go to the address specified in the MAIL FROM command, which overrides any Return-Path: header specified in the SMTP DATA. If you used the SendEmail API to send the message, then the notifications are delivered as follows: If you specified the optional ReturnPath parameter of SendEmail, then notifications go to that address. Otherwise, notifications go to the address specified in the required Source parameter of SendEmail, which populates theFrom: header of the message. If you used the SendRawEmail API to send the message, then the notifications are delivered as follows: If you specified the optional Source parameter of SendRawEmail, then notifications go to that address, overriding anyReturn-Path: hea…

How to enable http access of Jenkins

Edit the /etc/sysconfig/jenkins

and change

JENKINS_PORT="8888" or "

Now start jenkins service with the following command from terminal

service jenkins start

you can check the status : with following command

service jenkins status

How to Edit HTML to easily Add Gadget/Widget Sections Anywhere in Blogger

To add a gadget or widget section in your blogger blog, add the following code to your template html: <b:section class='newsectionclass' id='uniquesectionid' maxwidgets='1' showaddelement='yes'/><div style='clear: both;'/> You can add a b:section tag anywhere between <body> and </body> in your blogger blog. See the table below about the b:section tag and its attributes; Elementdescription<b:sectionb:section tag indicates the place or section to add widget/gadget in the blogger blog.
For adding gadget this code is a must. You can add this tag anywhere in between the body tag of your blogger template. class=’newsectionclass’The class of a b:section tag. It is better to use a unique class of’uniquesectionid’The id of the b:section tag and it must be a unique one. This is also handy if you want to add custom CSS code for it.maxwidgets=’1′Indicates the number of gadgets or widgets can be used inside the section. Valu…

Example Methods of browser Console object

Console.assert()Log a message and stack trace to console if first argument is false.Console.count()Log the number of times this line has been called with the given label.Console.debug()An alias for log();Console.dir()Displays an interactive listing of the properties of a specified JavaScript object. This listing lets you use disclosure triangles to examine the contents of child objects.Console.dirxml()Displays an XML/HTML Element representation of the specified object if possible or the JavaScript Object view if it is not. Console.error()Outputs an error message. Console._exception()An alias for error(); a new inline group, indenting all following output by another level. To move back out a level, call groupEnd().Console.groupCollapsed()Creates a new inline group indenting all following output by another level; unlike group(), this starts with the inline group collapsed, requiring the use of a disclosure button to expand it. To move back out a level, call groupEnd…


If you're running on Nginx then you can add the following to your site config this listens for any requests coming to your site on port 80 with is HTTP, then will redirect the user to the request page on HTTPS. server { listen80;; rewrite^/(.*)$1 permanent;

How to update/modify a file inside a jar

The Jar tool provides a u option which you can use to update the contents of an existing JAR file by modifying its manifest or by adding files. The basic command for adding files has this format: jar uf jar-file input-file(s) In this command: The u option indicates that you want to update an existing JAR file.The f option indicates that the JAR file to update is specified on the command line.jar-file is the existing JAR file that is to be updated.input-file(s) is a space-delimited list of one or more files that you want to add to the JAR file. Any files already in the archive having the same pathname as a file being added will be overwritten.
See Updating a JAR File.

GitHub’s major features

Each time you create a repo you get access to all of GitHub's major features including version control, Issues, Wiki, etc. Even with non-code objects you can submit pull requests and make incremental changes.

AWS WAF is a web application firewall that helps protect your web applications from common web exploits that could affect application availability, compromise security, or consume excessive resources.

AWS WAF gives you control over which traffic to allow or block to your web applications by defining customizable web security rules. You can use AWS WAF to create custom rules that block common attack patterns, such as SQL injection or cross-site scripting, and rules that are designed for your specific application. New rules can be deployed within minutes, letting you respond quickly to changing traffic patterns. Also, AWS WAF includes a full-featured API that you can use to automate the creation, deployment, and maintenance of web security rules.

How to quickly set up your own personal VPN server with Docker

CID=$(docker run -d --privileged -p 1194:1194/udp -p 443:443/tcp jpetazzo/dockvpn) docker run --rm -t -i -p 8080:8080 --volumes-from $CID jpetazzo/dockvpn serveconfig
docker run -d --privileged -p 1194:1194/udp -p 443:443/tcp --name vpn cdrage/openvpn-server
docker run --rm -ti -p 8080:8080 --volumes-from vpn cdrage/openvpn-server serveconfig

Check docker is running:
$ docker ps -a CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 88fdb2af8888 jpetazzo/dockvpn:latest "/bin/sh -c run" About a minute ago Up About a minute>1194/udp, 8080/tcp,>443/tcp boring_heisenberg
To fetch the config open up a webbrowser and connect to your docker box’s IP on port 8080. You’ll likely get some security errors because this is being served over HTTPS without the correct certificates. It’s safe to ignore these errors. You ca…

How To install Docker on Oracle Linux

To install Docker on Oracle Linux 6:Enable theol6_addonschannel in/etc/yum.repos.d/public-yum-ol6.repoRun:# yum install docker To install Docker on Oracle Linux 7:Enable the ol7_addonschannel in/etc/yum.repos.d/public-yum-ol7.repoRun:# yum install docker

Trading Forex.

Why? You don't need a ton of cash to start trading - you can quite literally make a fortune with a "kitty" as small as $100! You don't have to wait months or years to see significant results - some of my students are seeing returns of up to 30% PER MONTH!

Automation is a must

With the growing adoption of containers, microservices, and serverless architecture, the cloud is evolving and moving quickly.

In order to keep up with today's complexity of application development, automation is a must.

Tilix is a powerful, flexible, and easy to use terminal emulator.

Tilix requires a graphical user interface (GUI) and can't be used in an environment like a text-only console. It was written using GTK3, with some effort to conform with the GNOME Human Interface Guidelines (HIG). It can be launched from your distribution's application launcher. It could also be launched from the command line of an already running terminal session such as Xterm or Konsole.

AWS Elastic Beanstalk and App Engine are often described as similar offerings

But there are significant differences in their approaches. Both offer auto-scaling, load balancing, monitoring, etc., but unlike App Engine, Elastic Beanstalk requires the typical system administration that raw VMs require (OS updates, etc.). App Engine is a platform as a service (PaaS), meaning that it's fully managed, so all of these administrative tasks are handled by Google. The basic App Engine setup includes built-in services such as Task Queues, Memcache, Users API, and more.

Serverless applications offer benefits of an increase in speed of development, reduction in required code, and simplicity with scale.

Serverless doesn't mean there are no servers - it just means the developer doesn't have to worry about servers. A large part of traditional application development is answering questions around scaling, hosting, and monitoring solutions to meet the demands of the application. With Serverless, these questions are taken care of as part of the solution. In addition, Serverless applications are billed on a consumption-based plan. If the application is never used, a charge is never incurred. These features allow developers to focus solely on the business logic of the solution.

Linux System Hardware Information Commands

Hardware InformationKernel detected hardware
# dmesg # Detected hardware and boot messages # lsdev # information about installed hardware # dd if=/dev/mem bs=1k skip=768 count=256 2>/dev/null | strings -n 8 # Read BIOS Linux# cat /proc/cpuinfo # CPU model # cat /proc/meminfo # Hardware memory # grep MemTotal /proc/meminfo # Display the physical memory # watch -n1 'cat /proc/interrupts' # Watch changeable interrupts continuously # free -m # Used and free memory (-m for MB) # cat /proc/devices # Configured devices # lspci -tv # Show PCI devices # lsusb -tv # Show USB devices # lshal # Show a list of all devices with their properties # dmidecode # Show DMI/SMBIOS: hw info from the BIOS FreeBSD# sysctl hw.model # C…