Using an SSH tunnel to step debug through a firewall

In a previous post I covered how to set up PHP step debugging in Zend Studio. But if that doesn’t work there may be a firewall in between the server and the debugging client, or IDE, preventing the connection. Here is a possible way to get around that.

Note: Of course there is no way to avoid the firewall, but this post assumes a connection to the server using SSH is possible. What we’ll do is allow communications from the server to the client using the Zend Studio default debugging port (10137) forwarded through an SSH tunnel which uses port 22 by default. For this to work an SSH connection must be possible from the client to the server.

While it is possible to do this using command line from Linux or Mac, or using PuTTY on Windows, this example will use the built-in SSH capabilities of Zend Studio 13. For older versions of Zend Studio I recommend using command line or PuTTY linked above.

Assuming step debugging in Zend Studio was already set up as outlined in my previous post we will continue using that setup, but enhance it with an SSH tunnel.

In Zend Studio open the preferences. (Windows|Preferences) With the preferences open, expand the PHP node to get to Servers. Highlight the server configuration to work with, and click Edit.

Screenshot from 2016-04-18 15:07:40

When the Edit Server dialog opens select the SSH Tunneling tab. Check the box to Enable SSH Tunneling, and populate the desired Username and Password. If your server requires the use of an SSH Private Key in order to login, please supply that.

Screenshot from 2016-04-18 14:41:34

Now that the SSH connection is set up we need to add the Port Forwarding for the debugging port. Do this by clicking the Add button in the Port Forwarding section.

Screenshot from 2016-04-18 14:43:45

NOTE: The SSH command would look like this:

$ ssh -R 10137:127.0.0.1:10137 [email protected]: -p 22

Select ‘remote’ to specify which side of the tunnel will be sending communication on the forwarded port, enter the local address the remote side (server) will use and port number to send to. Then enter the port number on the receiving end (the client). Now click Finish to apply the setup, and click finish to exit the preferences.

In the PHP Servers view (Windows|Show View|PHP Servers) right-click the server we just added SSH Tunneling support to and select Open SSH Tunnel. You should then see a brief dialog letting you know the connection was made.

Screenshot from 2016-04-18 14:52:41

We are ready to debug!

Since I was using Zend Server in this example I have Z-Ray available, and while on a page I wished to debug I could simply click on the debug icon and select any of the debugging options.

Screenshot from 2016-04-03 15:24:13

This will cause Zend Debugger to contact Zend Studio for debugging, which in turn will ask the user if they wish to open the debugging perspective.

IMPORTANT NOTE: Debugging over an SSH tunnel is not fast. Therefore you may notice a lag between initiating the debug session and your IDE reacting. After that things speed up, but the initial connection is slow on many networks.

Screenshot from 2016-04-03 15:24:44

If Yes is selected the IDE is now ready to perform any debugging the user desires.

Screenshot from 2016-04-03 15:27:24

Happy debugging!!!

This post is one in a series on debugging. For others click below:

PhpStorm and debugging issue
Setting up step debugging in Zend Studio
Setting up local debugging with PhpStorm

Setting up remote step debugging with Zend Studio

Recently I was helping someone set up step debugging of PHP in Zend Studio to debug a remote site, and had some difficulties. So I decided to create this post to remind me later, and perhaps help others get it set up.

I was doing this on an Ubuntu laptop, so while menus may vary slightly the process should be very similar regardless of OS. Also, I did this using a local VirtualBox virtual machine, using Bridged networking mode to simulate a remote server. In Zend Studio I had a project created with the Zend Framework Skeleton Application, and created a virtualhost in the virtual environment that mirrored that.

NOTE: If the desire is to use a local server the setup is much simpler.

Server setup

While this post doesn’t cover how to install Zend Debugger or Xdebug, ensure one of these are set up correctly. Also, ensure the debugger of choice “knows” where to find the IDE to be debugging from. Zend Debugger can try to do this automatically, or an IP can be manually specified within Zend Debugger or Xdebug. Also, if using Zend Debugger ensure the IP of the client is added to the whitelist. More on how to verify this IP from the client later.

Aiming at the server

The first step, assuming you already have a project created in Zend Studio, is to add a server to the project configuration. Do this in the preferences. (Windows|Preferences)  With the preferences open, expand the PHP node to get to Servers.

Screenshot from 2016-04-03 15:17:07

From there click “New”, and follow the wizard for setup. The first step is to specify the type of server. In my case I was using an install of Zend Debugger that comes with Zend Server, so selected Remote Zend Server. Alternatively I could have easily selected Generic PHP Server to arrive at the same endpoint later.

Screenshot from 2016-04-03 15:17:47

Next, after giving this server a name and URL (ensure the URL actually hits the server), I am prompted for the Zend Server login credentials to gain access to the Zend Server Web API.

Screenshot from 2016-04-03 15:19:09

Entering the user and password authorizes Zend Studio to pull down an API key for interacting directly with Zend Server if I desired to later. (This creates a new Zend Server Web API Key on the server specifically for this client.) Alternatively it is possible to click Cancel and enter the credentials manually.

Again, this is not really required for simply debugging, but I’m including it for completeness sake.

Screenshot from 2016-04-08 09:25:43

At this point a test can be run to ensure we are hitting the server as expected by clicking the Test button.

NOTE: If this doesn’t end in a success you may have some network issues to overcome. See my post on using an SSH Tunnel if you need to.

Screenshot from 2016-04-03 15:20:12

After a success, click OK and then Finish the wizard. If you had troubles, please see my post for using an SSH tunnel.

Enable debugging for the project

With the server set up it is now possible to set up debugging for the Zend Studio project.

In the Preferences (Windows|Preferences) click on the Debug within the PHP node.

Screenshot from 2016-04-03 15:21:16

Though it is possible to specify the PHP Server globally from the resulting option screen I prefer to set up preferences for each project, since most of my projects may be different in any way. So I click Configure Project Specific Settings… link at the top of the dialog and am prompted to specify which project I desire to configure.

Screenshot from 2016-04-03 15:21:57

After selecting the appropriate project I can then appoint the server I just added above, and then specify the Base Path and ensure the Auto-generated Base URL is correct in the lower section.

Screenshot from 2016-04-03 15:22:26

After approving and closing the Preferences, we are ready to debug!!!

Test: If the following step doesn’t work it may be because the debugger on the server cannot find the IDE. In a browser check what ports the IDE is listening on by entering the following URL to hit Zend Studio’s built in web server.

Screenshot from 2016-04-08 09:48:52

If the debug_host doesn’t show an IP address reachable by the server then it may be necessary to manually specify the IP in Zend Studio by altering the server configuration we created previously.

If the IP address should be reachable by the server the issue may be in the configuration on the servers end, or perhaps a firewall or load balancer in between is limiting. Please see my post on how to get around this with an SSH tunnel.

Since I was using Zend Server in this example I have Z-Ray available, and while on a page I wished to debug I could simply click on the debug icon and select any of the debugging options.

Screenshot from 2016-04-03 15:24:13

This will cause Zend Debugger to contact Zend Studio for debugging, which in turn will ask the user if they wish to open the debugging perspective.

Screenshot from 2016-04-03 15:24:44

If Yes is selected the IDE is now ready to perform any debugging the user desires.

Screenshot from 2016-04-03 15:27:24

I hope this helps others. Happy debugging!!!

This post is one in a series on debugging. For others click below:

PhpStorm and debugging issue
Using an SSH tunnel to step debug through a firewall
Setting up local step debugging with PhpStorm

PHPStorm and debugging IP issue

Recently I was helping someone troubleshoot an issue using PhpStorm and Zend Debugger. In this case Zend Studio was able to debug an application using Zend Debugger while PhpStorm was failing unless an SSH tunnel was used. The error received was:

Host ‘127.0.1.1’ is not allowed to open debug sessions – please configure zend_debugger.allow_hosts in the ini file.Failed to connect to host ‘127.0.0.1’, reason: ‘Connection refused’.

The person experiencing this issue was attempting to debug a site in a VirtualBox virtual machine from the host machine. Both the host machine and the virtual machine were running Ubuntu 14.04. At first glance I thought adding 127.0.1.1 to the allowed hosts would do it. But turns out it was more than that.

In this case we knew there was not a firewall blocking access, so it had to be networking.

To start things off I wanted to take a look at what PhpStorm was listening to, so I used the broadcast port 20080 to see this in a browser:

Screenshot from 2016-04-04 16:13:09

So it appears PhpStorm was attempting to use the IP addresses linked to the host systems ‘localhost’ and ‘hostname’, but not an IP address accessible via the network. This meant the server would never be able to send information back to the IDE without the use of an SSH tunnel, because it could not reach 127.0.1.1 or 127.0.0.1 of the host.

Unfortunately PhpStorm doesn’t provide a way to alter the listening IP addresses in the preferences, so we were left with either using an SSH tunnel to allow port forwarding of the listening port (10137) back to the host, or manually informing Zend Debugger where the IDE would be located.

Zend Debugger Tweak

By default Zend Debugger will automatically attempt to detect the IDE settings, as shown below:

Screenshot from 2016-04-04 16:23:04

However, this wasn’t working because PhpStorm was not reporting a usable IP address, so we needed to update the settings manually:

Screenshot from 2016-04-04 16:22:37

NOTE: Checking the box “Use browser’s IP Address” did not fix the issue. The IP address needed to be entered.

With this done, the server now knew where to reach the IDE for debugging sessions. One downside to this is if the host machines IP address changes, this setting will need to be updated.

This post is one in a series on debugging. For others click below:

Setting up step debugging in Zend Studio
Using an SSH tunnel to step debug through a firewall
Setting up local step debugging with PhpStorm

Edit: Please head out to the PhpStorm ticket system and +1 this fix to make this a thing of the past. https://youtrack.jetbrains.com/issue/WI-7465

Mirror mobile device screen to your computer

I needed to perform a demo of a tool where I would utilize my mobile device (phone) to perform an action, and it caused a reaction on my laptop.  However, part of the “WOW” factor is to mirror my mobile device screen onto my laptop so the viewer can see both the mobile device and the web browser.

Thanks to Apple’s AirPlay this is relatively easy for the iPhone with the purchase of 3rd part software like Air Squirrels Reflector, but I don’t have an iPhone. (I can never figure out how to switch between apps, or how to go back if the app developer didn’t include a back button in the app.  But I digress.)  Instead I have an Android device, which has a much larger user base, and I really didn’t want to switch.  Unfortunately nobody has created a 3rd party application that utilizes the Cast Screen functionality of Android in the same manner as the AirPlay.

In searching I found many solutions that required the user to “root” their mobile device.  This really wasn’t an option for me.  I have a Google Nexus device, so I’m not really held back by mobile vendor limitations, lock downs, or pre-installed software.  No need to “root” my device.  I’ve rooted/unlocked other mobile devices in the past, and since I’m not a mobile developer, I feel no need to tinker with what works for me.

I did manage to find a couple other solutions (one with the help of my co-workers) that did work without altering my device software, or installing applications on my laptop.  Well, that is not entirely true.  Both of the solutions I’m about to share did require the Java runtime environment to be installed, but I consider that a mute point since most computers these days already have it installed for one reason or another. (Most developer IDE’s already require it, so I already had it.)

Step 1 – Ensure you have JRE

As I said, for this to work you will need to have the Java Runtime Environment of some sort installed on your system.  If you don’t already have the JRE installed you can do it at http://java.com.

Step 2 – Connect with USB

You must connect your Android device to your PC via USB connection for this to work.  As of this writing I have not found a way to make this wireless.

Step 3 – Enable Developer Mode

By default Android devices do not come with Developer Mode enabled.  This mode is needed so we can take advantage of debugging via USB tether.

On Android devices prior to 4.2 you could set USB Debugging from the settings…easy-peasy.

To enable this on Android 4.2+ go into Settings->AboutPhone and tap the Build Number 7 times.  The device will inform you that Developer Mode is now enabled.  Click back to hit the previous screen and you will now see Developer Options available.  Check the box for USB Debugging and you’re done.

Step 4 – Download the Android developer tools

For simplicity sake I only downloaded the standalone Android SDK Tools Only. (I had no use for the Studio.) I did this at the URL http://developer.android.com/sdk/index.html#Other, then unzipped the file to a place of my liking.

After making the file ‘/tools/android’ executable I ran it on the system.  This opens the Android SDK Manager window.  The purpose for this is to download and install the needed packages to allow us to “develop” Android apps.  I didn’t change a thing and simply clicked the button that said “Install n packages”. (Note: n will be some sort of number.)

It took awhile for the manager to do the update/download, but after it was completed I simply closed it.  This would have downloaded a bunch of things, but the most important for us is ‘/platform-tools/adb’ which is required to mirror our device screen to the PC. (Make sure this file is executable as well.)

Step 5 – Add locations to the PATH

For this screen sharing to work you will need to add two folders of the Android SDK to your PATH: ‘/platform-tools’ and ‘/tools’.  I did this by editing my .bashrc file as follows:

export PATH=$PATH:/home/aculp/android-sdk-linux/platform-tools:/home/aculp/android-sdk-linux/tools

Step 6 – Download Apps

There are two possible apps to use to do this:

Both carry the same sorts of functionality, however Droid @ Screen is a bit more mature and makes additional options a little easier.  One thing I didn’t like was the need to have an extra window open for the settings.  Due to my being a fan of simplicity I have been using Android-Screen-Monitor.

Both apps are a simple matter of executing the jar file using java and they just work.

Step 7 – Launch it!

Now it is simply a matter of launching either the Android-Screen-Monitor or [email protected] application. I did this via CLI like so:

$ java -jar asm.jar

NOTE: This command assumes we changed directory to where we downloaded the Android-Screen-Monitor jar file.

Conclusion

If you have questions or comments please post them.  I will return to this post and tweak it a bit more to become really easy to use, but for now this is mostly what I did.

Clone Hard Drive to External USB Drive via CLI

Thumb and USB drives

No matter what OS you’re cloning, using “dd” via command line will still work.  I personally tested while cloning a 1TB Ubuntu hard drive to a fancy new 1TB SSD.

Backstory: I purchased a new Dell 7737 laptop with a 1TB hybrid drive, which turned out to be slower than watching paint dry compared to the old SSD I’d been using for a few years.  Otherwise it is a kickass laptop.  So I purchased a 1TB SSD after finding they are roughly 50 cents per GB these days…very affordable.

First I put the new SSD into USB caddy I had laying around for backup purposes.

Next I created a bootable USB stick with an Ubuntu ISO image following the instructions at:

Windows = http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-windows
Ubuntu = http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-ubuntu
MAC = http://www.ubuntu.com/download/desktop/create-a-usb-stick-on-mac-osx

With the USB stick created I booted the system to Ubuntu using the USB LiveCD disk image.  It may require a BIOS change to enable the PC/Laptop to boot from USB device.  Doing this will not make any changes to your current hard drive as long as “Install Ubuntu” is not chosen.

Once booted up I was able to use Gparted, which is a standard app on the LiveCD, to create a new partition table on the new drive in the external USB caddy.

I then used fdisk via command line to find all disks and gain their identifiers needed.

fdisk -l

With the new partition and the identifier of the USB drive I was now ready to initiate the copy.  I used the following command to do that:

dd if=/dev/sdc of=/dev/sdb mb=8M && sync

NOTE: ‘if’ = read from and ‘of’ = write to.

It takes a very long time for this to finish up, especially with larger drives, but the end result was a working drive with my data on it.

After completion I simply switched out the SSD from the caddy with the internal HD in the laptop and all worked well.

Good luck!