Virtualization with Vagrant

 some rights reserved by MedithIT

While going ahead with Chef configuration management tutorials i came across "Vagrant". I heard this term many a times. For quite sometime i thought it was just another VirtualBox like application. until i finally started using it.

What is Vagrant?

Open Source application for creating and configuring virtual dev environment. Vagrant manages VMs hosted in VirtualBox. Basically its a commandline utility that allows you to communicate with VirtualBox (or any virtualization software) with an easy set of commands. Many describe it as a wrapper around the virtualization software too.

How is it used?

Fist of all download Vagrant for your OS from this link. Install it. As mentioned its a commandline utility tool, you need commandline to access this.

1. You will need to initialize vagrant box using the init command. This will initialize a vagrant environment in the present directory you are in. The second argument will set the name for your box and the third will set the URL to access in the Vagrant file.
   
• Syntax: vagrant init [box-name] [url-to-access]
• Example: vagrant init precise32 http://files.vagrantup.com/precise32.box
2. Next you need to create and configure the vagrant box as per your vagrant file. Use the up command for this. This command will be used frequently as this is how you start you machine as well.
   
• vagrant up
3. Now that the machine has started you still have not logged in to the machine. You can use ssh to login. You don't need to use the traditional long ssh command to login to your box a simple vagrant ssh suffices.
   
• vagrant ssh
• Note: Please check the documentation on the vagrant website as there is a list of optional parameters that you may need in case you run into any errors. Fatal can be expected.
4. To check valid configurations to ssh into a running vagrant box use vagrant ssh-config
• vagrant ssh-config
5. As you now know how to setup and start using your vagrant box, we also need to know how to shut it down. This is simple too by just a "vagrant halt" similar to the halt command in linux machine.
• vagrant halt
6. These were the few basics of vagrant. You can do more with vagrant as well. The vagrant box command gives you other alternatives that you could try out.
• vagrant box add [box-name] [url-path]
• This adds a box with the specified name using the local file path or url specified to access it.
• vagrant box list
• Lists all the boxes installed and available
• vagrant box remove [box-name] [provider]
• Removes the box with the specified box name for the specific provider. Providers are VirtualBox or VMWare or any other utility.
• vagrant box repackage [box-name] [provider]
• Repackages the given box and puts it to present directory for redistribution purpose. When a box is added, vagrant unpacks and stores it internally and the original box is not preserved.
7. Restarting a vagrant machine can be done using vagrant reload. Its equivalent to a vagrant halt and vagrant up.
• vagrant reload
8. To check the current state of the machine, i.e to verify if the machine is running, stopped or not created etc a status command helps
• vagrant status
9. To save the status of the machine and suspend it so that you can resume it at a later instance and not completely shut it down, you can use suspend command.
• vagrant suspend
10. To resume a suspended machine use vagrant resume
• vagrant resume
11. Finally, to stop and delete/destroy and existing machine use the destroy command. All the resources allocated are destroyed as if the machine was never there. This command asks for confirmation before destroying.
• vagrant destroy

Checking Open Ports on a Remote Computer using PortQry

Some rights reserved by Ryan Franklin

 Today for one of the projects the SFTP connection kept failing for some reason. The user-id password used for connecting to the host was correct the hostname was as well correct. There was no way to find out what went wrong. Thankfully command-line gives a good log to verify what goes wrong.

I tried connecting to the SFTP host with various tools like FileZilla, WinSCP but could not get good enough logs. Finally i tried connecting the server using ssh on command-line using my Ubuntu machine. The connection used to time out. That is what i see in the logs as well. I assumed that probably the SFTP port number 22 was closed for the host.

I googled for if i could find a tool to check if a particular port on a machine is accessible or not. I finally found something called as PortQry taht could be used on Windows machine using Commandline.

Its a very small 140 KB command-line based software tool that you can use to check if a port on some machine is accessible or not.

After using this tool i got to know that the machine had a Firewall  kind of protection which wasn't allowing me to access the SFTP port on it.

Here's how you PortQry on Windows:

• Download the software using the link : http://www.microsoft.com/en-in/download/details.aspx?id=17148

• Double click an unzip the files to any location say C:/

• Hit Windows+R in the run box enter "cmd"

• Go to the directory where the PortQry was extracted.

• Execute the program PortQry by entering PortQry<enter>

• This will display a list of help information and the correct usage of the command

The following is the syntax to check the port status :
portqry -n myhostname.net -e 80

PortQry can inform the status of a port as "Listening", "Not Listening", or "Filtered"
Listening : There is some service active on that port
Not Listening : Port is closed
Filtered : No response, Presumably its behind some kind of firewall.

Syntax
portqry -n name_to_query [-p protocol] [-e || -r || -o endpoint(s)]

Common command line switches:
-n : IP address or name of system to query
-p : TCP or UDP or BOTH (default is TCP)
-e : single port to query (valid range: 1-65535)
-r : range of ports to query (start:end)

For single port use
portqry -n 127.0.0.1 -e 80

For a Range of ports, use the -r switch:
portqry -n 127.0.0.1 -r 80:85

Note:
- PortQry also displays extended information for known services, such as SMTP, POP3, IMAP4, FTP, and is capable of performing LDAP queries.
- A GUI based alternative is also available now called PortQryUI

Sample Output:
C:\PortQryV2>portqry -n 127.0.0.1 -e 40
Querying target system called:
 127.0.0.1
Attempting to resolve name to IP address...
Name resolved to xx.xx.xx.xx
querying...
TCP port 22 (ssh service): FILTERED

C:\PortQryV2>portqry -n 127.0.0.1 -e 80
Querying target system called:
 127.0.0.1
Attempting to resolve IP address to a name...
IP address resolved to xx.xx.xx.xx
querying...
TCP port 80 (http service): LISTENING

C:\PortQryV2>portqry -n 127.0.0.1 -e 22
Querying target system called:
 127.0.0.1
Attempting to resolve IP address to a name...
IP address resolved to xx.xx.xx.xx
querying...
TCP port 22 (ssh service): NOT LISTENING

Data Recovery with TestDisk

some rights reserved by epSos .de

 You buy a portable hard disk drive to keep a back up of all your important data, Or you are carrying an extremely important doc in a USB drive, or you have some data on your internal hard disk drive. You try to get the data and ... boom!!! No Data!!! You have absolutely no clue how to get back the important data you had in the drives. Finally you just consider it lost and curse your fate and carry on.

This happened to me too. 1 TeraBytes of important data in my external Hard disk drive got corrupt in a second and was lost. I tried all OS's i could right from MAC to Windows to Linux but no luck. I was about to give up when i came across Data Recovery softwares on Internet.

Data Recovery softwares are those softwares that help you read corrupt/lost/deleted data from your drives. There were so many softwares out there. I started trying out my luck on all the softwares i could with a windows machine(i should not have done that, but i have no option!!). Unfortunately most of them just gives a list of deleted items on the disk that i never needed. One or two of them did get me the data however since they were trial versions, i could only view the data and not copy them. Anyways it just gave me the hope that the data was still there in the disk.

Finally i searched for Open Source alternatives and there i got my answer. TestDisk!!!

What is TestDisk?
As per their website wiki: TestDisk is a free data recovery software designed to help recover lost partitions and/or make non-booting disks bootable again when these symptoms are caused by faulty software, certain types of viruses, or human error. It can also be used to repair some filesystem errors.

Installation:
You don't need to install it. Its a very small 1.5 MB software, where you just need to run the executable, it was really easy to use command line based software with most of the information self explanatory.

Steps to Use:

1. Logs Creation : Like every other Linux based software, this one as well makes a log of every session carried out. when you execute the TestDisk.exe You are 1st asked for if, you would like to CREATE a new log, APPEND  the existing log, or want NO LOG.
2. Media/Disk Detection :Next you need to select the disk you want to recover the lost data from. It shows a list of all volumes connected to you computer and you can select using keyboard arrow keys.
3. Disk/Partition Table Type Selection : The next screen prompts you to select the partition table type. In most of the cases it detects all by itself the type. Otherwise it keeps it to none for you to select. Mine was a windows machine that i was running this program on and i used this with quiet a many volumes and every time it detected Intel. I am assuming windows users could probably select Intel in case they are unsure of this option. But selection "None"is not recommended as its very rare that a drive is non partitioned.
4. Next Screen Gives the following Options :

Analyse Analyse current partition structure and search for lost partitions to restore them
Advanced Filesystem Utils

FAT: Boot and FAT repair

NTFS: Boot and MFT repair

ext2/ext3: Find Backup SuperBlock
FAT file undelete
NTFS file undelete
ext2 file undelete
Image Creation

Geometry Change disk geometry

Options Modify options

MBR Code Write TestDisk MBR code to first sector

Delete Delete all data in the partition table

Analyzing of disk is done to look for lost partitions. This takes long time based on the size of the disk. Most of the times for windows if you get an error "The type of the file system is RAW." or "The disk in drive D is not formatted. Do you want to format it now?" then that means the Boot sector is damaged. You can click on Advanced file system Utils and and use the FAT: Boot and FAT repair/NTFS: Boot and MFT repair based on the type of partitioin you have. This was the problem with my disk too and got corrected in no time.



To be contd ...