Centos Nginx Python3.4 uWSGI Emperor

Tutorial

Here are steps:

1. # yum upgrade
2. $ curl -O http://fedora.mirror.nexicom.net/epel/6/i386/epel-release-6-8.noarch.rpm
3. # yum localinstall epel-release-6-8.noarch.rpm
4. $ curl -O http://yum.postgresql.org/9.3/redhat/rhel-6-x86_64/pgdg-centos93-9.3-1.noarch.rpm
5. # yum localinstall pgdg-centos93-9.3-1.noarch.rpm
6. # yum install postgresql93-server postgresql93-contrib postgresql93-devel
7. # service postgresql-9.3 initdb
8. # service postgresql-9.3 start
9. # chkconfig postgresql-9.3 on

At this point CentOS6 is fully updated and running postgres. Time to install nginx.

This should go in /etc/yum.repos.d/nginx.repo

        [nginx]
        name=nginx repo
        baseurl=http://nginx.org/packages/centos/$releasever/$basearch/
        gpgcheck=0
        enabled=1


Aside: This configures a repository for nginx, provided by the nginx team.

1. # yum install nginx
2. # service nginx start
3. # chkconfig nginx on

At this point nginx is installed and running (Although not yet configured for YOUR needs). Time to install Python3.

1. # yum groupinstall 'development tools'
2. # yum install zlib-dev openssl-devel sqlite-devel bzip2-devel xz-libs pcre-devel
3. $ curl -O http://www.python.org/ftp/python/3.4.0/Python-3.4.0.tar.xz
4. $ xz -d Python-3.4.0.tar.xz
5. $ tar -xvf Python-3.4.0.tar
6. $ cd Python-3.4.0
7. $ ./configure
8. $ make
9. # make altinstall
10. # ln -s /usr/local/bin/python3.4 /usr/bin/python3

Python3 is installed at this point. Time to create virtualenvironments.

1. $ cd /srv/
2. $ python3 -m venv uwsgi
3. $ source /srv/uwsgi/bin/activate
4. $ pip install uwsgi

Place the following in /etc/init.d/uwsgi

(This script could be improved)

        #!/bin/sh
        #
        # uwsgi        Startup script for uwsgi
        #
        # chkconfig: - 85 15
        # processname: uwsgi
        # description: uwsgi is an HTTP and reverse proxy server
        #
        ### BEGIN INIT INFO
        # Provides: uwsgi
        # Required-Start: $local_fs $remote_fs $network
        # Required-Stop: $local_fs $remote_fs $network
        # Default-Start: 2 3 4 5
        # Default-Stop: 0 1 6
        # Short-Description: start and stop uwsgi
        ### END INIT INFO

        # Source function library.
        . /etc/rc.d/init.d/functions

        DAEMON=/srv/uwsgi/bin/uwsgi
        DAEMON_OPTS="--ini /srv/uwsgi/emperor.ini"
        OWNER=uwsgi
        NAME=uwsgi
        RETVAL=0

        get_pid() {
            if [ -f /var/run/$daemon_name.pid ]; then
                echo `cat /var/run/$daemon_name.pid`
            fi
        }  

        case "$1" in
          start)
            echo -n "Starting $NAME: "
                PID=$(get_pid)
                if [ -z "$PID" ]; then
                    [ -f /var/run/$NAME.pid ] && rm -f /var/run/$NAME.pid
                    touch /var/run/$NAME.pid                                        
                    chown $OWNER /var/run/$NAME.pid
                $DAEMON $DAEMON_OPTS
                fi
            ;;
          stop)
            echo -n "Stopping $NAME: "
                PID=$(get_pid)
                [ ! -z "$PID" ] && kill -s 3 $PID &> /dev/null
                if [ $? -gt 0 ]; then
                    echo "was not running"
                    exit 1
                else
                echo "$NAME."
                    rm -f /var/run/$NAME.pid &> /dev/null
                fi
            ;;
          reload)
                echo "Reloading $NAME"
                PID=$(get_pid)
                [ ! -z "$PID" ] && kill -s 1 $PID &> /dev/null
                if [ $? -gt 0 ]; then
                    echo "was not running"
                    exit 1
                else
                echo "$NAME."
                    rm -f /var/run/$NAME.pid &> /dev/null
                fi
            ;;
          force-reload)
                echo "Reloading $NAME"
                PID=$(get_pid)
                [ ! -z "$PID" ] && kill -s 15 $PID &> /dev/null
                if [ $? -gt 0 ]; then
                    echo "was not running"
                    exit 1
                else
                echo "$NAME."
                    rm -f /var/run/$NAME.pid &> /dev/null
                fi
                ;;
          restart)
                $0 stop
                sleep 2
                $0 start
            ;;
          status) 
            killall -10 $DAEMON
            ;;
              *) 
                N=/etc/init.d/$NAME
                echo "Usage: $N {start|stop|restart|reload|force-reload|status}" >&2
                exit 1
                ;;
            esac
            exit 0

**Run the following, to keep selinux happy**

1. # semanage fcontext -a -t initrc_exec_t -r s0 "/etc/init.d/uwsgi"
2. # restorecon /etc/init.d/uwsgi

**Run the next commands to auto-start uwsgi-emperor on boot** *and turn off when system turns of*

1. # chkconfig --add nginx
2. # chkconfig nginx on
3. # service nginx start

Place the following in /srv/uwsig/emperor.ini

      [uwsgi]
      uid = uwsgi
      gid = uwsgi
      emperor-pidfile = /var/run/uwsgi.pid
      emperor = /srv/uwsgi/vassals
      master = true
      die-on-term = true
      daemonize = true
      logto = /srv/uwsgi/log/emperor.

##What is left to do?

A metric crapload. You are about 25% of the way finished at this point. You still are required to do the following:

1. Place your vassal file in /srv/uwsgi/vassals.
2. Create database to use in postgres.
3. Configure your firewall. Both IP-tables and AWS Security Policy.
4. Configure nginx to to work with your vassal.

##Optional:

* DNS?
* Redundancy
* Configure Backups?

## Additional NOTE:

For pip to be able to install psycopg2, it needs to be able to find pg_config.

Easiest way to do this, is to add "/usr/pgsql-9.3/bin" to your path.
Alter your ~/.bash_profile to include it: 

        PATH=$PATH:$HOME/bin:/usr/pgsql-9.3/bin
        export PATH

Then source it:

        source ~/.bash_profile