I love it when the big companies share some insight into how they solve a problem.
Australians
http://techblog.realestate.com.au/
Big Global Players
https://engineering.twitter.com/
http://developers.instagram.com/
http://instagram-engineering.tumblr.com/
https://engineering.pinterest.com/
http://nerds.airbnb.com/
https://blog.asana.com/
https://eng.uber.com/
TL:DR Updated Endian this morning, and the DHCP service failed to start. Turns out having a 2nd DNS server set in the Web GUI doesn’t correctly write to the dhcp.conf file. Solution. Remove 2nd DNS server or manually add a comma (,) into the config file using nano.
In the Web GUI under “Status -> System Status”
The DHCP server was shown as “Stopped”.
Manually starting from the shell also failed.
‘service dhcpd start’
A quick look in the logs:
‘cat /var/log/messages’
Feb 25 10:22:51 endian dhcpd: Internet Systems Consortium DHCP Server V3.0.5-RedHat Feb 25 10:22:51 endian dhcpd: Copyright 2004-2006 Internet Systems Consortium. Feb 25 10:22:51 endian dhcpd: All rights reserved. Feb 25 10:22:51 endian dhcpd: For info, please visit http://www.isc.org/sw/dhcp/ Feb 25 10:22:51 endian dhcpd: /etc/dhcpd.conf line 21: semicolon expected. Feb 25 10:22:51 endian dhcpd: option domain-name-servers 192.168.0.3 192. Feb 25 10:22:51 endian dhcpd: ^ Feb 25 10:22:51 endian dhcpd: Configuration file errors encountered -- exiting Feb 25 10:22:51 endian dhcpd: Feb 25 10:22:51 endian dhcpd: If you did not get this software from ftp.isc.org, please Feb 25 10:22:51 endian dhcpd: get the latest from ftp.isc.org and install that before Feb 25 10:22:51 endian dhcpd: requesting help. Feb 25 10:22:51 endian dhcpd: Feb 25 10:22:51 endian dhcpd: If you did get this software from ftp.isc.org and have not Feb 25 10:22:51 endian dhcpd: yet read the README, please read it before requesting help. Feb 25 10:22:51 endian dhcpd: If you intend to request help from the [email protected] Feb 25 10:22:51 endian dhcpd: mailing list, please read the section on the README about Feb 25 10:22:51 endian dhcpd: submitting bug reports and requests for help. Feb 25 10:22:51 endian dhcpd: Feb 25 10:22:51 endian dhcpd: Please do not under any circumstances send requests for Feb 25 10:22:51 endian dhcpd: help directly to the authors of this software - please Feb 25 10:22:51 endian dhcpd: send them to the appropriate mailing list as described in Feb 25 10:22:51 endian dhcpd: the README file. Feb 25 10:22:51 endian dhcpd: Feb 25 10:22:51 endian dhcpd: exiting.
Luckily the log points us in the right direction.
/etc/dhcpd.conf line 21: semicolon expected. Feb 25 10:22:51 endian dhcpd: option domain-name-servers 192.168.0.3 192.
In the Web GUI if I remove the 2nd Name server, all is well, the service starts up and the log shows requests being received.
When I add it back in, it fails to start again.
When I add the comma in using nano, I’m able to manually start the service.
Although I’m sure it will break if any changes are made to the web gui.
Update: It appears that this bug has been around for a few days, and is reported: https://jira.endian.com/browse/UTM-1388
TL;DR: Bridged ASDL modem over VLAN – yes it can work!
The problem:
x86 Router (Endian) has run out of physical network cards, but more WAN ports are required, can we do something with a ‘Router on a stick’ and use a VLAN aware Switch?
We can do this in a ‘double NAT’ style configuration, but can we do it in a bridged mode configuration. It seems that we can in fact. However I’m using a L3 switch (Dell 6248) I have tired in the past to use a HP PS1810-8G Switch (J9833A) without successful (granted I didn’t spend too much time on it).
Update: Try and use iPython Notebox instead….makes this stuff easy by default :)
Need to have a ‘pretty’ version of a dictionary, in PHP I would use:
print “<pre>”
print_r($array);
but in python……?
Use pprint
import pprint pp = pprint.PrettyPrinter(indent=4) pp.pprint(thing)
All the info you need: Pretty Print
Personal TL;DR notes on getting this to work, not a tutorial.
Download Install Anaconda
– At the time of writing it didn’t create Windows Shortcuts, fix this with openning cmd as admin
‘c:\Anaconda2\scripts\conda.exe install menuinst’
Agree to Updates
‘c:\Anaconda2\scripts\conda.exe install -f console_shortcut ipython ipython-notebook ipython-qtconsole launcher spyder’
Agree to updates.
Now there should be shortcuts in:
C:\ProgramData\Microsoft\Windows\Start Menu\Programs\Anaconda2 (64-bit)
Now onto Xero
The last two commands fix the error: ImportError: No module named jwt.algorithms
Again these are personal notes, not a full blown tutorial.
Just ran into a strange issue when configuring a SNMP community on the web interface. Alas it was broken.
And clicking on “add’ results in an error
‘Access Error: Request Entity Too Large’
An easy fix is to stop being lazy and CLI into the switch and fix it.
The command:
snmp-server community public su 192.168.0.5
And look, it works for us. Now you can webconfig until your heart is content.
Don’t forget to write your switch config changes.
Reference: Dell 5424 CLI Manual, Page 328 ‘snmp-server community’
Service discovery failed for this host: Agent exited with code 255: Pseudo-terminal will not be allocated because stdin is not a terminal. Host key verification failed.
Current Setup: Ubuntu 14.04 running OMD
Solution: Running the ssh command from the OMD user appears to fix the problem by allowing them into the known hosts list.
Here’s how:
linuxuser@ubuntu_vm:~$ sudo su
[sudo] password for linuxuser:
root@ubuntu_vm:/home/scadmin# su [omd-site-name]
ubuntu_vm[[omd-site-name]]:~$
then run your remote command eg:
ubuntu_vm[[omd-site-name]]:~$ ssh -l root -i /etc/check_mk/check_mk.key [ip]
It will ask to save the host to the known hosts, type yes and enter. It should then output the status from the check_mk agent.
The great debate in the wonderful land of mobile devices, Apple vs Google. But what happens when you start to mix ecosystems between the two.
I’m an iPhone 4s (stop laughing, I realise it’s 2025) and iPad mini 2 guy, but when it comes to putting content on my TV, I’ve tested both the Apple TV & the humble Chromecast & funnily I prefer the…..Chromecast.
The Apple TV allows sharing of your screen (which is nice to have), along with the ability to stream apps & games, but the downside, no multitasking. Say you flick a Netflix movie up from your iPad to your Apple TV, then head over safari which then sends you to YouTube, bam! Netflix stops showing your movie. However with the Chromecast you can multitask, you can watch your Netflix Movie on your TV & your YouTube clip on your iPad.
The way Netflix & the YouTube apps hand off to the Chromecast allow you to continue using the app & search for more content to watch, the YouTube app even allows for “queuing” up content.
Unfortunately the Chromecast doesn’t support mirroring from the iPad. But you can mirror from the Google Chrome web browser with the aid of an extension which I haven’t used an awful lot, but it is handy.
So if you want a cheap way to show Netflix or YouTube from your iPad to your TV, the humble $50 Chromecast is a winner.
My own personal directory of photography / AV shops in and around Melbourne:
Protog – http://www.protog.com.au
Image Melbourne – http://www.imagemelbourne.com.au
Dragon Image – https://www.dragonimage.com.au
Side note – These guys sell a LP-6 replacement battery which seems to be holding up strong after 6 months of use, for around half the price of a Canon one – Jupio LP-E6. Their online store seems to ship from Sydney.
Vanbar Imaging – http://vanbarphoto.com.au
Factory Sound – http://factorysound.com/
These guys are more for sound and the A side of AV.
Thanks to James for introducing me to half of these stores. :)
Back in 2014 I brought a copy of Lightroom 5.
Unfortunately after buying a Canon 7D Mk II and finding out it won’t tether with Lightroom 5, I looked into upgrading to Lightroom 6.
It turns out that if have brought Lightroom 5 after 22 march 2015 you get a free upgrade. Unfortunately for me I had brought Lightroom almost 12 months earlier. No free upgrade for me :(
Now the question beckons, do I upgrade to Lightroom 6 or fork out $10/month for the Photography bundle :/
