07/30/09
Barcode (GTIN) field for Django -
Categories: It was pretty simple in the end. You can find the item with and without zero padding.
Code:
from django.db import models | |
class BarcodeField(models.IntegerField): | |
__metaclass__ = models.SubfieldBase | |
| |
def to_python(self, value): | |
if value is None: return | |
return "%014.0d" % value | |
| |
def get_db_prep_save(self, value): | |
if value is None: return | |
return int(value) |
And using it:
Code:
from project import cfields | |
class Product(models.Model): | |
status = models.IntegerField() | |
barcode = cfields.BarcodeField() |
Code:
>>> eeepc = Product(name="ASUS Eee PC 1005HA-PU1X-BK 10.1-Inch Black Netbook", status=1) | |
>>> eeepc.barcode=304 | |
>>> eeepc.barcode | |
'00000000000304' | |
>>> eeepc.save() | |
>>> eeepc.barcode | |
'00000000000304' | |
>>> eeepc.barcode=39584 | |
>>> eeepc.save() | |
>>> Product.objects.get(barcode="00000000039584") | |
<Product: ASUS Eee PC 1005HA-PU1X-BK 10.1-Inch Black Netbook> | |
>>> Product.objects.get(barcode="00000000039584").barcode | |
'00000000039584' | |
>>> Product.objects.get(barcode=39584).barcode | |
'00000000039584' |
07/05/09
So, I have been having some problems with my ISP again. However, I have a 3G modem (Option iCON 225) that works in Linux, but you cannot pass it to DomU directly by creating a bridge and attaching that. So I have a following setup:
Internet<->modem<->
Dom0
Internet<->DomU<->
There is several things I need to do:
0. Get DKMS
1. Get hso driver
1.1. Unpack it to /usr/src/hso
1.2. dkms add -m hso -v 1.9; dkms build -m hso -v 1.9; dkms install -m hso -v 1.9
2. Obtain some scripts
2.1. cp -f hso.udev /etc/udev/rules.d/z20_hso-udev.rules; cp -f rezero /usr/sbin/; /etc/init.d/udev restart
2.2. Stick the modem in
2.3. Modify the connect.sh script:
Find line “route add default dev $NETDEV". Modify it to following:
ip route add default dev $NETDEV table 10 ip route add $INTERNALRANGE dev $INTERNALBRIDGE table 10 iptables -t nat -A POSTROUTING -s $BACKUPIP -o hso0 -j SNAT --to-source $PIP iptables -t nat -A PREROUTING -i $NETDEV -j DNAT --to-dest $BACKUPIP ip rule add from $BACKUPIP/32 to any table 10
INTERNALRANGE=Your internal IP range, for example 10.49.2.0/24.
INTERNALBRIDGE=Your internal bridge device, for example xenbr0
BACKUPIP=Router’s IP which you will set as source for the packets that you want to pass thru the 3G modem
Find line “ifconfig $NETDEV down". Modify it to following:
ip route flush table 10 iptables -t nat -D POSTROUTING -s $BACKUPIP -o hso0 -j SNAT --to-source $PIP iptables -t nat -D PREROUTING -i $NETDEV -j DNAT --to-dest $BACKUPIP ip rule add from $BACKUPIP/32 to any table 10 ifconfig $NETDEV down
You also might to comment out the resolv.conf lines.
2.4. Modify conninfo.ini
Note! Dom0 should have IP routing enabled, so “echo 1 > /proc/sys/net/ipv4/ip_forward". Use sysctl to set it at the boot time
3. Set the DomU
3.1. Add $BACKUPIP to $INTERNALBRIDGE
3.2. Add to boot script (for example, /etc/rc.local):
ip route add $INTERNALRANGE dev $INTERNALBRIDGE ip route add default via $DOM0IP dev $INTERNALBRIDGE ip rule add from $BACKUPIP lookup 10
Test with:
traceroute -s $BACKUIP ping.funet.fi
haruhi:~# traceroute -s 10.2.255.1 ping.funet.fi
traceroute to ping.funet.fi (128.214.248.132), 30 hops max, 40 byte packets
1 nanoha.serv.azt (10.2.0.10) 0.000 ms 0.000 ms 0.000 ms
2 ge0-0-1-650.esptnl-pe1.fi.elisa.net (213.161.47.241) 1384.000 ms 1384.000 ms 1416.000 ms
3 ae2.heltli-gw1.fi.elisa.net (139.97.6.246) 1416.000 ms 1456.000 ms 1536.000 ms
4 csc.ficix1-ge.ficix.fi (193.110.226.14) 1616.000 ms 1616.000 ms 1692.000 ms
5 helsinki0-x4100-csc0.funet.fi (193.166.255.154) 1736.000 ms 1784.000 ms *
6 ns-secondary.funet.fi (128.214.248.132) 424.000 ms !X 504.000 ms !X 556.000 ms !X
Now everything sent to your modem will be redirected to DomU. Unfortunally the only way to detect them is to match everything but interal IPs, but you can improve this if you want (for example, by setting ToS or creating new bridge for DomU-Dom0 communication).
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