When you are trying the Flask flaskr tutorial, you may encounter this error:-
AttributeError: 'Flask' object has no attribute 'teardown_request'
I was initially stumped, but then realised the catch. I’m reading the tutorial for Flask v0.7.
I installed Flask v0.61 from pypi, which is the current stable version.
Solution;-
easy_install Flask==dev
This was already put in the github project page.
After installing Fedora 15, you may find your
eth0 network card (NIC) is no longer present when you do an ifconfig. e.g:-
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:36008 errors:0 dropped:0 overruns:0 frame:0
TX packets:36008 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:3368266 (3.2 MiB) TX bytes:3368266 (3.2 MiB)
p34p1 Link encap:Ethernet HWaddr 20:CF:30:0F:37:4A
inet addr:192.168.0.10 Bcast:192.168.0.255 Mask:255.255.255.0
inet6 addr: fe80::22cf:30ff:fe0f:374a/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:3010801 errors:0 dropped:1 overruns:0 frame:0
TX packets:2249595 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:4355046356 (4.0 GiB) TX bytes:180163909 (171.8 MiB)
Interrupt:69 Base address:0x2000
What has happened is, from Fedora 15 onwards, they have implemented a new feature called Consistent Network Device Naming.
As a result, embedded NICs will be shown as em1, em2 etc, while PCI network cards will have the name pp.
As seen from the output of my motherboard, my eth0 is actually a PCI add on card number 34, and is using slot number 1.
But my card is built-in to the motherboard. Shouldn’t it be em1 or something?
This is by design of your motherboard. These cards are integrated PCI addons, done by the manufacturer itself.
Virtual Machines however, will have their cards remain as eth0 etc.
You can disabled this feature by appending the following into your grub.conf kernel commandline:
biosdevname=0
For more information, look at the Fedora 15 page.
When is the Centos 6 release date?
A question that keeps popping up for most people, as there has been much silence on this.
The good new is: Very soon! After lurking around their mailing lists, the QA team have started getting their packages / rpms / isos around since the 3rd of June 2011.
They hope to start syncing it to external (if QA passes) by 13th July 2011. So
there’s a high possibility we may get it on the 14th of July 2011.
Lets keeps our fingers crossed ya?
Update: Sob Sob, due to some issues identified by QA, its currently targeted to be sync to external mirrors on the 4th of July 2011. :(
VirtualBox is a popular Virtualization
product for Windows, Linux, Mac & Solaris. They have a RPM repository set up
so people can alway get the latest version of it.
To install, first become root, and then download the repo file and save it in
/etc/yum/repos.d.
wget http://download.virtualbox.org/virtualbox/rpm/fedora/virtualbox.repo -O /etc/yum.repos.d/virtualbox.repo
Then install the dkms package to make sure your kernel gets host kernel modules each time the kernel is updated.
yum install dkms.noarch
Finally, install VirtualBox 4.0:
yum install VirtualBox-4.0
Gvim, the graphical version of vim is a pretty
cool addition to your existing vim editors. However, sometimes the default
font seems to be lacking and you may want to change it.
To do that, first go into your preferences and select the font you wish to use. In Windows, this is Edit -> Select Font.
Then, in command mode, type
:set gfn?
You should get something like at the bottom of this picture: [caption
id=”attachment_309” align=”aligncenter” width=”300” caption=”Font name as
described by GVIM”]
[/caption]
This step is important, as it tells you how vim sets the font name
In my case, I chose the Windows font Lucida Console at 12 pixels, so GVIM shows it as
guifont=Lucida_Console:h12:cANSI
What we need to do, is now edit your
.vimrc
and add the following line:-
set guifont=Consolas:h12:cANSI
The next time you launch GVIM, the default font should be Lucida Console.
Sometimes, just using sudo isn’t enough. You may need an extended session to do work as the root user. At times like this, the following command will save your day:-
sudo -i
The -i means interactive, and opens a root shell, assuming you have sudo priviledges.
While we wait for
Centos to release Centos 6, there are a few
alternatives for the impatient.
While they are good for the impatient who wish to try out the latest & greatest ‘stable’ builds of RHEL for free, I’d suggest waiting for Centos 6. Rumours? lurking around the centos mailing lists are that QA releases will be with the testers soon, so we probably might get them in a month or two.
As much as I’d like to try out the latest releases, I stand firmly by their decision to continue with updates for the existing Centos installed base first, before focusing on rebuilding a whole new distro.
Like they say, there’s an installed base of Centos 5 users, but you don’t see any Centos 6 users yet.
If you really need support, you should purchase a subscription from Red Hat. This helps their continued development of our favourite Enterprise Linux.
With the release of Fedora 15, they have introduced a totally new GNOME. One thing long time Gnome users may find missing is the ability to change their font sizes.
Fortunately, GNOME has a nice little utility called the Gnome Tweak Tool.
Install is using:
sudo yum install gnome-tweak-tool
One of its many options is changing the font size. [caption
id=”attachment_288” align=”alignleft” width=”150” caption=”Gnome Tweak
Tool”]
[/caption]
Sometimes when editing configuration files or for quick debugging on a server, you use vim. And you wish it could show line numbers.
Actually it can. Here’s how:
In command mode, type
set number
.
Yup, that’s it.