I ran into this bug which prevented me to update yum packages, and after a quick search, this helped to fix it:
# vim /usr/lib/python2.7/site-packages/urlgrabber/grabber.py
Go to line 1539, with vim you can use :1539
Replace the line with this:
if cur > (float(max_size)*1.10):
Django is a great web framework and we have several ways to deploy it in production.
You can use apache too for example, but for django my favorite is nginx + gunicorn.
Nginx is a well-known player and it will be used as front-end. Gunicorn is not as well-known, but it has proved to be quite stable (instagram and pinterest use it).
Installation:
yum install nginx pip install gunicorn
Previously you have to have installed python pip and epel repository.
Next step is to run gunicorn, which is quite easy. As we are going to run it with a django project, it is possible to use gunicorn_django
cd /path/to/your/django/project gunicorn_django --workers=4 -b 127.0.0.1:8888 -D
And that is it. We have told gunicorn to run with 4 workers (processes), to listen on localhost:8888 and to run in background with -D.
Last step is to configure a server for nginx:
upstream app_server_djangoapp {
server localhost:8888 fail_timeout=0;
}
server {
listen 80;
server_name server.com;
access_log /path/log/access.log;
error_log /path/log/error.log info;
keepalive_timeout 5;
# path for static folder
location /static {
root /path/to/static/;
}
location / {
proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
proxy_set_header Host $http_host;
proxy_redirect off;
if (!-f $request_filename) {
proxy_pass http://app_server_djangoapp;
break;
}
}
}Restart nginx:
service nginx restart
Our django site is deployed, as easy as that.
Some of my library was in m4a files, which I have problems to play, furthermore I prefer having everything in mp3 format.
So I wrote the following script:
echo "Dependencies: mplayer and lame" if [ $# -lt 1 ]; then echo "Usage: sh m4a2mp3.sh '/path/to/files'" else echo "This could take sometime. Converting to 320kbps MP3 files..." sleep 1 cd "$1" for i in *.m4a; do mplayer -ao pcm "$i" -ao pcm:file="$i.wav"; done for i in *.wav; do lame -h -b 320 "$i" "$i.mp3"; done echo "Cleaning the house..." rm -rf *.m4a rm -rf *.wav fi echo "All files converted. Thank you."
Usage is pretty straightforward:
sh m4a2mp3.sh /path/to/your/songs
The only dependencies, as you can see also in the script are mplayer and lame
You can install them with the following command:
# Yum based (Fedora, CentOS, SuSE) yum install mplayer lame # Apt based (Debian, Ubuntu, Mint) (NOT TESTED) apt-get install mplayer lame
As always, you also can find the script on my Github.
More simple than it may seems. It will take care of adjusting months and days automatically:
Working with days:
// My date Y-m-d $mydate = "2012-05-06"; //Adding five days $newdate = date(“Y-m-d”, strtotime($mydate. " +5 days”)); // Substracting five days $newdate = date(“Y-m-d”, strtotime($mydate. " -5 days”));
Working with weeks:
// My date Y-m-d $mydate = "2012-05-06"; //Adding two weeks $newdate = date(“Y-m-d”, strtotime($mydate. " +2 weeks”)); // Substracting one week $newdate = date(“Y-m-d”, strtotime($mydate. " -1 week”));
Working with months
// My date Y-m-d $mydate = "2012-05-06"; //Adding six months $newdate = date(“Y-m-d”, strtotime($mydate. " +6 months”)); // Substracting three months $newdate = date(“Y-m-d”, strtotime($mydate. " -3 months”));
Working with years
// My date Y-m-d $mydate = "2012-05-06"; //Adding ten years $newdate = date(“Y-m-d”, strtotime($mydate. " +10 years”)); // Substracting two years $newdate = date(“Y-m-d”, strtotime($mydate. " -2 years”));
Be aware of the Unix Millenium Bug
I’ve written a simple Python script to backup and restore installed rpm packages.
On Ubuntu, I used APTonCD for this matter, but in this case, for Fedora I decided to use my own script.
The usage is quite simple, only two parameters:
Backup:
python rpm-backup.py --backup
Restore:
python rpm-backup.py --restore
This is source code, although you can download it from my github (link to the gh-page of the entire repository)
#!/usr/bin/python
''' Backup script for installed packages.
Only RPM.
Tested under Fedora
Error list:
Code 1: Missing modules
Code 2: Not root
Code 3: Tried to restore without backup file'''
print " ____ ____ __ ___"
print " / __ \/ __ \/ |/ /"
print " / /_/ / /_/ / /|_/ / "
print " / _, _/ ____/ / / / "
print " /_/ |_/_/ /_/ /_/ "
print " ____ ___ ________ ____ ______ "
print " / __ )/ | / ____/ //_/ / / / __ \ "
print " / __ / /| |/ / / ,< / / / / /_/ /"
print " / /_/ / ___ / /___/ /| / /_/ / ____/ "
print " /_____/_/ |_\____/_/ |_\____/_/ "
#Import modules
try:
import os
import argparse
except ImportError:
print "Could not find required modules. Exiting..."
exit(1)
# Create parser
parser = argparse.ArgumentParser(description='Backup your installed packages.', epilog="Written by Adrian Espinosa (aesptux).")
# if user types --backup it will be stored as true in variable backup
#if user types --restore it will be stored as true in variable backup
parser.add_argument('--backup', action='store_true', dest='backup', help='Backup your packages.')
parser.add_argument('--restore', action='store_true', dest='restore', help='Restore your packages.')
args = parser.parse_args()
#print args
#print(args.option(args.integers))
#variables
userlogged = os.environ['LOGNAME']
directory = '/%s' % (userlogged)
filename = 'packages-installed.bak'
path = directory + '/' + filename
rpm_list = []
print " "
print "Hello %s!" % (userlogged)
print "If you are having troubles using the script, use the argument '--help'"
def dobackup():
''' Create backup '''
print "Starting copy..."
command = 'rpm -qa > ' + path
#os.system('touch '+path)
os.system(command)
os.system('echo Total packages: ; cat ' + path + ' | wc -l ')
print "Done."
def dorestore():
''' Restore packages'''
print "Starting restore..."
global rpm_list
# try, except, to see if the backup file exists
try:
for line in open(path, 'r'):
rpm_list.append(line)
except IOError:
print "The backup file does not exist. Please, create a backup first. "
exit(3)
# take the list and join it
rpm_list = ''.join(rpm_list)
# remove \n
rpm_list = rpm_list.replace('\n', ' ')
os.system('yum install ' + rpm_list)
#This script must be run as root
if userlogged != 'root':
print "You have to run the script as root"
exit(2)
# if backup is true, dobackup. Else if restore is true, dorestore
if args.backup == True:
dobackup()
elif args.restore == True:
dorestore()
Then, you can set up a cron job like this:
0 22 * * * /usr/bin/python /root/rpm-backup.py --backup
Just in case you do not know, tail prints the last ten lines of the indicated file. Like this:
tail /var/log/yum.log
Furthermore, if you want to print more lines you can do it with -n parameter:
tail -n 20 /var/log/yum.log
But I think the most interesting parameter for tail is -f. This parameter allows tail to “follow” the file. New data is displayed as the file grows.
Now, using sed we can append to each new line, a bell sound:
tail -f /var/log/yum.log | sed -e $'s/$/\a/'
Notice that ‘$’ escape sequences will only work on bash.
This was tested on Fedora 16.
We cannot return two variables from a function, but we could use an array for that.
So for example, in JavaScript, it would be like this:
function foo() {
// do something here
// whatever
return [myvalue, myothervalue, otherthing];
}And then, for use those values:
foo()[0] // this is myvalue foo()[1] // this is myothervalue foo()[2] // this is otherthing
This can be applied to any other language you may know. And that’s how we return more than one value from a function