If ruby myapp.rb starts sinatra previewing at localhost:4567, how can I programatically stop/halt/kill it? Terminal command (other than Ctrl-C), or Rake tasks would be fine.
I need to incorporate this into a Rake task or terminal.
In myapp.rb, add this before sinatra starts:
puts "This is process #{Process.pid}"
When you want to kill it, do this in a shell:
kill <pid>
Where <pid> is the number outputted by myapp.rb. If you want to do it in ruby:
Process.kill 'TERM', <pid>
Both of these will let sinatra run it's exit routine. If you don't want to type in the pid every time, have myapp.rb open a file and put it's pid in it. Then when you want to stop it, read the file and use that. Example:
# myapp.rb:
File.open('myapp.pid', 'w') {|f| f.write Process.pid }
# shell:
kill `cat myapp.pid`
# ruby:
Process.kill 'TERM', File.read('myapp.pid')
In OS X, from the command line (Terminal.app, or DTerm) just enter:
$ killall ruby
every ruby process will stop. Sinatra too.
In Linux (and other UNIXes), you can:
$ ps aux | grep ruby
$ kill <ruby-process-id>
The simples way to do that:
kill #{Process.pid}
To do this in a simple repeatable way, there's a few methods.
Record the PID as you start your Sinatra server, e.g.
# Run the Sinatra server and send it to background (using &)
ruby my_sinatra_server.rb &
# Record the PID of the last background process (using $!)
MY_SINATRA_SERVER_PID=$!
# Now go ahead and do your stuff...
# When finished, kill the sinatra server (from the same shell)
kill $MY_SINATRA_SERVER_PID
Instead of using an env variable ($MY_SINATRA_SERVER) you can use a temporary file e.g. my_sinatra_server.pid
# Run the Sinatra server and send it to background (using &)
ruby my_sinatra_server.rb &
# Record the PID of the last background process (using $!)
echo $! > my_sinatra_server.pid
# Now go ahead and do your stuff...
# When finished, kill the sinatra server (from the same shell)
kill $(< my_sinatra_server.pid)
Related
I want to create a Ruby script, which will start like this:
$ ruby script.rb &
Then, I will close the console and it must stay alive, working in the background. At the moment I have to run it like this, in order to achive that:
$ nohup ruby script.rb &
I want to get rid of nohup and deal with SIGHUP directly inside the script -- simply ignore it. Is it possible?
Sure, just Signal.trap HUP signal:
def do_fork
$pid = fork do
Signal.trap("HUP") do
puts "Received HUP, ignoring..."
end
Signal.trap("TERM") do
puts "Received TERM, terminating..."
exit(0)
end
while true do sleep(10_000) end
end
Process.detach($pid)
end
do_fork
Copy the code above to some file and run it with ruby file.rb to see it ignores kill -HUP pid and closes on kill -TERM pid.
What is the best way to launch multiple process in background with ruby ? I need to use Thread.new ?
I have like 5 process to launch in background then i want to get the pid to stop properly all the process.In bash i can do it easyli:
htop &
echo $! >/tmp/htop.pid
And to kill:
kill `cat /tmp/htop.pid`
I want to be able to do the same thing with Ruby
You could use spawn:
pid = spawn('htop')
And to Process.kill:
Process.kill('TERM', pid)
I pretty much need what my Question statement says, currently I have a Capistrano task that looks like this:
desc "stops private pub"
task :stop_private_pub do
run "kill -9 $(lsof -i:9292 -t)"
end
before 'deploy', 'servers:stop_private_pub'
...And it works well when in fact the process in port 9292 is running, The problem is that when the process Isn't running this task will FAIL! and it Halts the whole Deployment Process!
I'm not a UNIX Shell expert, nor am I a Capistrano master, so.. I really need help improving this Capistrano Task, Is there a way to kill -9 only if the process is running?
How can I do this?
Thanks in advance.
You could use Capistrano's capture command (in V3 at least, probably a V2 equivalent) to grab the output from your lsof command, and then only if you get a PID run the kill command.
pid = capture 'lsof', '-i:9292', '-t'
if pid # ensure it's valid here
run "kill -9 #{pid}" # make darn sure pid is an integer if you embed it
end
You could also do:
run "kill -9 $(lsof -i:9292 -t); true"
or add on error continue:
task :stop_web, :roles => :app, :on_error => :continue do
run "dosomething.sh; true"
end
If you start a command in a remote server with the net/ssh gem, and the command is on a deadlock, how do find the pid of the process running in the remote server and kill it?
Does net/ssh gem support this?
Well, if you can ssh into the remote server, you can use this to get the pid of the process:
# Assuming the command you want to kill is a ruby program.
# If the program is something else, say sparrow mail app, you should replace
# ruby with sparrow below.
ps -ax | grep ruby
And then, perhaps:
kill -9 <pid>
I want to control many different Sinatra apps from a central (Sinatra) app.
The problem I have is no matter which way I exec/spawn/fork the call to start it, I cannot get the pid of the Sinatra server so that I can kill (:int) it?
This is due to my shell exec string, which contains a few other commands first, so I get the pid of the first.
My command string is like
command = source ~/.profile; rbenv #{ver}; some_env=1234 ruby app.rb
So I get the pid of the sh process of the sourcing command.
The question is, how can I get the pid of the ruby command launched above?
I am currently using spawn, but have tried most others as well, but I don't think that is the problem!?
pid = Process.spawn(command)
pid # => 1234
The ruby app itself starts
$ ps aux
1234 sh -c . ~/.profile; shell_script
4567 shell_script
I want to know 4567!?
There's no easy way of getting your '4567', but you should be able to make your process have the same pid as Process.spawn returns.
Try ending your command with an exec rather than a straight call to ruby, i.e.:
source ~/.profile; rbenv #{ver}; export some_env=1234; exec ruby app.rb
you can check whether the process "shell_script" is a child of "sh -c . ~/.profile; shell_script".you can check this through "ps -axgf" command.
if it is a parent then u can use the group id of pid 1234 (get it form the output of ps -axgf) to kill the child with pid 4567 using this command .
kill -9 -1234(assumming 1234 is the group id)