I was just setting SSL on nginx for one of customers, that was extremely easy, everything done in few minutes, the nginx documentation guided me step by step, even with custom certificates.
If you ever had been considering switch then just have a look on the documentation, there is nothing to add: http://wiki.nginx.org/HttpSslModule.
Some time ago I have migrated my server to nginx. Now I got first chance to setup rails application on it.
Searching for new experiences I have tried a new setup – passenger standalone on rvm monitored by god and cron (see Q&A on the end).
Prerequisite to that guide is a working deployment script (putting files on server and db:migration working also rvm set up on server). Important is also to replace all occurrences of “/path/to/application” with your real path to application on server.
Nginx is also required, in case you do not have it already you can install it with following command (ubuntu server on linode):
sudo apt-get install nginx
Assuming you have an deploy script up and running you need to add few changes before deployment.
First add god configuration, in your RAILS_ROOT create file config/local.god:
passenger_config = {
:instances => (1..3),
:path => '/path/to/your/application/current'
}
God.watch do |w|
w.name = 'Passenger'
w.start = "ps -U $USER u | grep -v awk | awk '/nginx/ {print $2}' | xargs kill 2>/dev/null ;
passenger start #{passenger_config[:path]} -d -e production \
-S #{passenger_config[:path]}/tmp/pids/passenger.socket --pid-file #{passenger_config[:path]}/tmp/pids/passenger.pid \
--min-instances #{passenger_config[:instances].min} --max-pool-size #{passenger_config[:instances].max}"
w.stop = "passenger stop #{passenger_config[:path]} --pid-file #{passenger_config[:path]}/tmp/pids/passenger.pid"
w.pid_file = "#{passenger_config[:path]}/tmp/pids/passenger.pid"
w.behavior(:clean_pid_file)
w.start_if do |start|
start.condition(:process_running) do |c|
c.interval = 5.seconds
c.running = false
end
end
end
Also new gems have to be added in Gemfile:
group :production do gem 'passenger', '~>3.0.5' gem 'god', '~>0.11.0' end
Now deploy both files to server, they will be needed later on, and do not forget to run
bundle install --without=production
before deployment.
Second add an request to restart passenger after deploy:
touch /path/to/application/tmp/restart.txt
If your deployment script is capistrano you should use the following snippet:
namespace :deploy do
[:start, :stop].each do |method|
task method, :roles => :app, :except => { :no_release => true } do
run "local_god #{method} Passenger"
end
end
task :restart, :roles => :app, :except => { :no_release => true } do
run "touch #{File.join(current_path,'tmp','restart.txt')}"
end
end
So now lets go to server to finish configuration.
We need to install god and passenger (which we added on the beginning):
bundle install --without=development test cucumber
please note that cucumber is only required when you use it, skip this param if cucumber is only an tasty vegetable for you.
One of most important steps is to create god wrapper that will be used for starting application (replace my_ruby_1.9.2@my_application with your rvm identifier):
rvm wrapper my_ruby_1.9.2@my_application local god
Next we need to make test run of passenger, it will also compile nginx and notify of any problems if it finds any:
cd /path/to/application/current ; passenger start
Passenger will be started on port 3000 if there is no firewall on server (you missed to install it) then you can visit your browser and enter your server.address:3000. adding -p 8080 would server application on the port 8080 (welcome java users). To stop passenger just hit CTRL+C :)
When that works we can set up proxy in the main nginx configuration. On ubuntu (linode) the steps look as follows:
sudo vim /etc/nginx/available-sites/your-application.conf
and put the following content (do not forget to replace my_domain with your dns name of the server):
server {
listen 80;
server_name my_domain;
access_log /var/log/nginx/my_domain.access.log;
error_log /var/log/nginx/my_domain.error.log;
location / {
proxy_pass http://unix:/path/to/application/current/tmp/pids/passenger.socket;
proxy_set_header X-Real-IP $remote_addr;
}
}
after that (ESC :wq) you need to link configuration and restart server
sudo ln -s /etc/nginx/sites-available/your-application.conf /etc/nginx/sites-enabled/your-application.conf sudo /etc/init.d/nginx restart
last step is to put local god into autorecovery mode with a simple cron job run crontab -e and enter the following content:
* * * * * ps aux | grep -v grep | grep -q "local\.god" || /home/user_name/.rvm/bin/books_god -c /path/to/application/current/config/local.god
That’s all, in one minute your server should be ready, do not forget that first call to passenger application might be sluggish, but it is only the first one when rails need to be initialized, rest of them is really fast.
To check the whole setup you could put small change in some view, deploy application, refresh your browsers (wait few seconds for rails startup) and check your results.
Q: Why passenger, why not unicorn or thin ?
A: It is extremely easy to set up.
A: It is one of the fastest ruby servers (some say it is fastest one).
A: It takes far less memory then glassfish or torquebox.
Q: Why passenger standalone, not integrated into apache or nginx ?
A: It is integrated with nginx, but installation is automated – almost no manual steps needed.
A: It runs from user context, so it can be fully controled by user and does not affect other users.
A: It does not need to recompile main server – no dependencies for serving other pages, multiple version can be run at the same time.
Q: Why rvm?
A: It allows easy maintenance of ruby version for user installations.
A: It allows to separate gem repositories for multiple applications.
Q: Why God ?
A: It allows easy monitoring and management of processes – in our case manage passenger standalone.
Q: Why Capistrano ?
A: Really?
Q: Why do you kill nginx when starting passanger ?
A: It’s a hack, it might sometimes happen that passenger process is already stopped but nginx did not finished it’s operation yet, so to allow new process to start we kill the old one.
Q: Can I ask a new question, or provide more answers
A: I encourage you to ask questions and give answers, of course I will post only those that give any value.
Over a year ago I have posted instruction how to setup simple git server, today I had to do it again but already having code so here is new instruction.
Create remote repository:
ssh mpapis@niczsoft.com -C "git init --bare repos/library3.git"
Create local repository:
git init
git add .
git commit -m "initial commit"
Tell local repository to synchronize with remote repository:
git remote add origin mpapis@niczsoft.com:repos/library3.git
git config branch.master.remote origin
git config branch.master.merge refs/heads/master
git push
You might be interested in the original post: fastest way to get git server
It has been long time since last post, but finally something useful shown up, today I want to present simple script for monitoring memory in Linux.
But first happy news: our server is now sucessfully migrated to nginx, no more apache, now maximal memory usage is 20MB per process.
So here is script, it is almost simple, find some processes, and kill them if to much RAM used:
#!/bin/bash
threshold_mb=25
kill_at_mb=$((threshold_mb*5))
memory=$(free -m | awk '{if (FNR==2) print $2}')
threshold=$((threshold_mb*100/memory))
kill_at=$((kill_at_mb*100/memory))
log=/dev/shm/psaux.log
count=$(ps aux | awk -v threshold=$threshold '{if (FNR==1 || $4>=threshold) print}' | tee $log | wc -l)
[ $count -gt 1 ] && echo "Showing processes over ${threshold_mb}MB, killing processes over ${kill_at_mb}MB" && cat $log
cat $log | awk -v kill_at=$kill_at '{if ($4>kill_at) print $2" "$4 }' | while read pid mem;
do
used_mb=$(($(echo $mem | sed 's/\.//')*memory/1000))
# fix rounding problem in awk
if [ $used_mb -gt $kill_at_mb ]; then
kill -9 $pid
echo "pid $pid used ${used_mb}MB - killed"
fi
done
rm -f $log
Most important in this script are first two variables, threshold_mb which is a limit for showing processes (it is rough comparison) and kill_at_mb which is limit for killing processes, by default this limit is 5 times bigger then showing threshold. Cause killing is more important operation additional check for used memory is more strict to be sure, only processes over the limit are killed.
Save it to disk and in crontab:
sudo crontab -e
add the following lines:
MAILTO=<your @email> * * * * * /root/bin/psaux.sh
That’s all, now add some filter in your mailbox to ignore mails form server – this is all automatic, but you might want to have this for later check if some important processes are missing.
I was searching for a fast and easy way to setup git server, and I found one, but I was not fully happy with it, so lets have a look on another way:
ssh mpapis@niczsoft.com -C "mkdir -p repos/library2.git; cd repos/library2.git; git --bare init"
git clone mpapis@niczsoft.com:repos/library2.git
cd library2/
touch test.txt
git add .
git commit -a -m "1st"
git push origin master
This is good way to keep Your private repo, just as central repo or backup, no packages needed, just git on both sides
The same can be done on local filesystem like shared storage(nfs or smb):
cd /remote
mkdir test.git
cd test.git/
git --bare init
cd
git clone /remote/test.git/
cd test/
touch test.txt
git add .
git commit -a -m "1st"
git push origin master
From now on it will be working by simply calling “git pull” and “git push”.
