I have a virtual machine on a cloud host that stays running in non-desktop mode. It has the Cinnamon desktop environment installed, but I don't typically leave the desktop environment open.
I have a cron job I'd like to run every hour which requires opening an app which requires a desktop environment (headful Chrome).
I've been able to schedule the cron job to use the desktop environment by adding the DISPLAY envvar in the job definition:
1 * * * * DISPLAY=:20 /path/to/script/to/execute
However, this only works when I use remote desktop software to open Cinnamon from my laptop.
I'd like to be able to leave the web server running, without having a remote desktop connection permanently open on my end, and run cron jobs that depend on a desktop environment.
Do y'all have a suggestion for running a cron job as I want to? Maybe a way to leave a desktop environment open without using a remote desktop? Or a way to open a desktop environment within a cron job?
If you don't have a display attached, you'll need to find a headless system that can run with a virtual DISPLAY. Headless Chrome is probably the easiest for you to swap in, and has convenient python bindings [related question].
You might also want to look into running selenium, depending on the task you need to run.
Finally, you might be interested in running a VNC server; depending on the config of your server, you can configure it to stay alive while your client disconnects. usually this is useful for temporary network hiccups, but set to a high enough timeout value, you may get the effects of a persistent, virtual, non-transient display.
Related
Let's state a situation:
I have the possibility to run arbitrary commands on a server as an unprivileged user, through "unconventional means".
I do not have the possibility to login using ssh to that server, either as my unprivileged user or anything else. So I do not have currently a CLI allowing me to run any commands I would like in a "normal" way.
I can ping that server and nothing prevents me to connect to arbitrary ports.
I still would like to have a command line to allow me to run arbitrary command as i wish on that server.
Theoretically nothing would prevent me to launch any program as my unprivileged user, including one that would open a port, allow some remote user to connect to it and just forward any commands to bash, returning the result. I just don't know any good program to do that.
So, does any one know? I looked at ways to launch ssh_server as an unprivileged user but some users reported that recent versions of ssh_server do not allow that anymore. Actually I don't even need ssh specifically, any way to get a working CLI would do the trick. Even a crappy node.js program launching an http server would work, as long as I have a CLI (... and it's not excessively crappy, the goal is to have a clean CLI, not something that bugs every two characters).
In case you would ask why I would like to do that, it's not related to anything illegal ^^. I just have to work with a very crappy Jenkins server for which I'm not allowed to have direct access to its agents. Whoever is responsible for that server doesn't give a sh** about its users' needs so we have to use hacky solutions just to have some diagnostic data about that server (like ram, cpu and disk usage, installed programs, etc...). Having a CLI that I can launch some time instead of altering a build configuration and waiting 20 minutes to have an answer about what's going on would really help.
Thanks in advance for any answer.
So do you have shell access to the server at least once? E.g., during the single day of the month when you are physically present at the site of your client or the outsourcing contractor?
And if you have shell access then, can you or your sysmin install Cockpit?
It listens on port 9090.
You can then use the credentials of your local user and open a terminal window in your browser. See sidebar item "Terminal" on the screenshots of the cockpit homepage.
According to the documentation
Cockpit has no special privileges and doesn’t run as root. It creates a session as the logged in user and has the same permissions as that user.
I'm trying to automate Coded UI tests.
My test controller launches the tests on a remote test server, which I normally access via a Remote Desktop connection.
Is it possible to run the Coded UI tests without having to connect via remote desktop?
Currently, the tests only run when I have connected via Remote Desktop, and the window must be open. When I close the Remote Desktop session, the tests do not run.
If it isn't possible to run coded UI tests without remote desktop, how can I automate connecting via remote desktop?
Thanks
As to your first question, the test agent needs to be "online" for tests to run. and the test agent is "online" only when the environment is in "ready" state.
You cannot run a test in an environment(remote connection/local machine) without it being in "Ready" state.
With regards to your second question about automating a desktop connection, this
link, however seems to be helpful:
Automating remote desktop connection
Coded UI tests are independent of Remote Desktop.
All UI tests are dependent on UI though. This means, the user must be logged in, and the screen cannot be locked.
Usually, when you disconnect from an RDP session, the screen gets locked. Also, you would have to set the user to auto-login in order for tests to be run. (RDP connections will also log you in.)
So, if you are able (allowed) to, easiest is:
Set user to auto-login.
Use VNC software for connection, like UltraVNC. You do not have the problem of the screen locking on disconnect.
You can automatically initiate RDP connection. I used it, and it is a bad idea, because it is fragile, and if it breaks, it will fail your tests (e. g. when you have it linked to a build job and it should run all the time).
I want to run few scripts (jmeter scripts) in few AWS ubuntu machines and windows7 machines. Usually I use WinScp (transfer files), putty (run commands) for linux and Remote Desktop Connection for windows machines, to do the work manually.
Now I want to automate these processes and would like to know how to achieve that. My intention is to write code to,
connect to these machines,
copy the scripts,
run the scripts,
fetch the log files and
close the machine
I also want to schedule them. What is the best way of doing this? Also I prefer that the code that I write can be hosted somewhere (so that rest api can be exposed) or called as a direct library (API) in my java server.
I know that chef scripts can be written, but want to know any other alternatives. https://www.chef.io/chef/
Thanks a ton in Advance.
I'm using the yii framework and trying to get its unit tests running while connected over ssh on a CentOS server. When I run phpunit, it tries to launch Firefox, which fails with the error "no display specifiied"
General theory
Error: no display specified
To understand that error message you first have to understand how the X Windowing System works - that is the name of the framework used by Linux (and other types of Unix) systems used to display graphical user interfaces.
X consists of two parts - there is a client and a server. Client is the program that wants to draw the interface - in your case that would be Firefox. Server is a program that makes drawing possible. There are X servers available for all the major operating systems. Linuxes and OSX usually ship with one, on Windows you will have to find and install one - Cygwin/X is one option, but there are others.
So why is this client/server architecture even necessary?
Most of the time its not even needed. If you happen to run Linux locally, then you will not even notice that there is any kind of client/server communication happening somewhere - but there is.
Where X shines though is that this architecture means that network capabilities are built right into it. You can run a client (Firefox) on one machine and display the GUI on a completely different machine. You could run 10 different clients on 10 different machines and have them all display output on a single machine thanks to X. Think VNC or Remote Desktop - X is somewhat similar, but you could say that its on steroids compared to those. And X has had this ability for a really long time.
Whenever your start up a X client (a program that wants to display graphical user interface) it looks for an X server. One possibility for the client to find one is an environment variable named DISPLAY. I'm on OSX and this is what I see.
[~]> echo $DISPLAY
/tmp/launch-ihNtDq/org.x:0
This point to my local X server. It could point to any server on my local network. When the client finds this environment variable it will connect to it and the user interface pops up.
If client cannot find this environment variable - you will get the familiar
Error: no display specified
Back to Yii
Looks like Yii has Selenium tests bundled. PHPUnit needs to start up Selenium RC to control a Firefox instance to run those tests. Selenium RC (or maybe Firefox itself) fails to find DISPLAY environment variable. And dies with the above error.
How do you solve this issue?
There are 3 options
1) install Yii, PHPUnit and all their dependencies locally. Selenium runs just fine on Windows. It wont use the X protocol on Windows, so none of that business with X clients and X servers. And you can then run Yii testsuite locally.
2) install an X server on your Windows box. Then enable 'X Forwarding' in your ssh client settings (or use the -X command line parameter for ssh). When you do that, then there will be a DISPLAY variable set when you are logged in to that CentOS server. You can verify it by typing the echo command above. Then the X client on CentOS can talk (show GUI) to the X server on your Windows machine - all the X traffic is tunneled over the ssh connection. This however means that you need java (which selenium RC is built in) and Firefox on that CentOS server. You may or may not have them there.
3) use a virtual framebuffer - for example Xvfb - an X server that performs all drawing operations in memory, not showing any output anywhere.
What good is that? Selenium has commands for taking screenshots at any point during the test run and saving them to files. For example a typical Selenium test would check whether an element exist on the page - and to make a screenshot when it does not. Screenshot would then be saved in a file, which you can view later to determine what the reason for the failure was. Making screenshots works just fine with a virtual framebuffer.
Final clarification
Note that Selenium tests are merely one type of tests that PHPUnit can run. Selenium in not required to write PHPUnit tests, its an optional add-on. But Yii testsuite apparently relies upon it.
Last, but not least
Integration tests (which Selenium tests are) are not usually ran on production systems, because there is a chance that test data is left behind in your production database. Also, getting good test results means isolating from external factors as much as possible - the contents of your production database will be constantly changing and this may affect your tests.
Normally all tests will be executed somewhere else (your development machine, dedicated QA server, whatever you have), before the new code is deployed to production servers. After all the point of tests is to verify that the system works after the changes. There is not much value in running them on production systems - the code does not change after it has been deployed.
Of course - its up to you - if you see value in doing those tests on production system, go right ahead.
Its simpler than you think. Run Selenium locally on your desktop, make sure phpunit is setup on the remote server. Then start a reverse SSH tunnel in your SSH connection. This varies depending on your SSH client. In PuTTY, there is a setting for SSH tunnels and you can reverse the direction by selecting the remote option. Check out this page for details. With OpenSSH from the command line, its done like this:
ssh -R 4444:localhost:4444 user#remoteserver
This will listen on the remote server on port 4444 and forward it to your selenium server running on localhost on your desktop port 4444.
Once you've done that, you'll need to change the TEST_BASE_URL setting in yourproject/protected/tests/WebTestCase.php to go to the remote server's URL for your yii project.
The simplest way to run a gui test on from another agent machine on a Windows client is to use "psexec" (http://technet.microsoft.com/en-us/sysinternals/bb897553.aspx).
We have a set of Mac machines (mostly PPC) that are used for running Java applications for experiments. The applications consist of folders with a bunch of jar files, some documentation, and some shell scripts.
I'd like to be able to push out new version of our experiments to a directory on one Linux server, and then instruct the Macs to update their versions, or retrieve an entire new experiment if they don't yet have it.
../deployment/
../deployment/experiment1/
../deployment/experiment2/
and so on
I'd like to come up with a way to automate the update process. The Macs are not always on, and they have their IP addresses assigned by DHCP, so the server (which has a domain name) can't contact them directly. I imagine that I would need some sort of daemon running full-time on the Macs, pinging the server every minute or so, to find out whether some "experiments have been updated" announcement has been set.
Can anyone think of an efficient way to manage this? Solutions can involve either existing Mac applications, or shell scripts that I can write.
You might have some success with a simple Subversion setup; if you have the dev tools on your farm of Macs, then they'll already have Subversion installed.
Your script is as simple as running svn up on the deployment directory as often as you want and checking your changes in to the Subversion server from your machine. You can do this without any special setup on the server.
If you don't care about history and a version control system seems too "heavy", the traditional Unix tool for this is called rsync, and there's lots of information on its website.
Perhaps you're looking for a solution that doesn't involve any polling; in that case, maybe you could have a process that runs on each Mac and registers a local network Bonjour service; DNS-SD libraries are probably available for your language of choice, and it's a pretty simple matter to get a list of active machines in this case. I wrote this script in Ruby to find local machines running SSH:
#!/usr/bin/env ruby
require 'rubygems'
require 'dnssd'
handle = DNSSD.browse('_ssh._tcp') do |reply|
puts "#{reply.name}.#{reply.domain}"
end
sleep 1
handle.stop
You can use AppleScript remotely if you turn on Remote Events on the client machines. As an example, you can control programs like iTunes remotely.
I'd suggest that you put an update script on your remote machines (AppleScript or otherwise) and then use remote AppleScript to trigger running your update script as needed.
If you update often then Jim Puls idea is a great one. If you'd rather have direct control over when the machines start looking for an update then remote AppleScript is the simplest solution I can think of.